UNIVERSE
1,000,000,000,000 YBN	1) We are a tiny part of a universe made of an infinite amount of space, matter and time.
995,000,000,000 YBN	11) There is no time I can identify as the start of the universe, the universe has no beginning and no end; perhaps the same photons that have always been in the universe continue to move in the space that has always been.
990,000,000,000 YBN	2) There is more space than matter.
980,000,000,000 YBN	3) All of the matter is made of particles of light humans have named ''photons''. Photons are the base unit of all matter from the tiniest particles to the largest galaxies.
960,000,000,001 YBN	5) Photons move 300 million meters every second in a line.
950,000,000,000 YBN	6) Matter is attracted to other matter and so photons form structures such as protons, atoms, molecules, molecule groups (like all of life of earth), planets, stars, galaxies, and clusters of galaxies. Gravity is responsible for photons forming Hydrogen, Hydrogen forming nebulas, nebulas forming stars, and stars forming galaxies.
940,000,000,000 YBN	7) All of the hundreds of billions of galaxies we can see are only a tiny part of the universe. Most of the galaxies in the universe we will never see because they are too far away for even 1 particle of light from them to be going in the exact direction of our tiny location, or are captured by atoms between here and there. One estimate has 70e21 (sextillion) stars in only the universe we can see. That is 10 times more stars than grains of sand on all the earth.
935,000,000,000 YBN	4) The patterns in the universe are clear. Photons form gas clouds of Hydrogen and Helium, these gas clouds, called nebuli condense to form galaxies of stars. The stars emit photons back out into the rest of the universe, where they collect and form clouds again. Around each star are many planets and pieces of matter. On many of those planets intelligent life evolves. This life moves their stars out of spiral galaxies to form globular clusters, and ultimately to transform spiral galaxies into elliptical galaxies that travel the universe looking for more matter to fuel their movement.
930,000,000,000 YBN	8) Photons from the most distant galaxies we can see are slowed because of delays with other photons in between here and there.
880,000,000,000 YBN	13) The Milky Way Galaxy forms, perhaps from a gas cloud that formed by capturing matter in the form of light from other stars, from the remains of a previously destroyed galaxy, or some combination of the two.
5,500,000,000 YBN	16) The yellow star earth will eventually orbit forms, perhaps in a nebula, when matter in the nebula starts accumulating and rotating as a result of gravity, or from the remains of an exploded star that condensed again under the influence of gravity. My opinion is that stars contain molten iron in their center, similar to the earth. [check with supernova remnants] The density of the star the earth rotates is similar to that of a liquid. The most popular theory to explain how stars give off so many photons is that these photons exit as a result of Hydrogen atomically fusing into Helium, and I want to add my opinion that potentially the pressure of gravity simply separates atoms of Hydrogen and helium into their source photons. Perhaps the reaction is similar to the center of the earth where red hot liquid iron emits photons. We obviously do not explain that red hot molten metal as being the result of nuclear fusion, but yet it is clearly not oxygen combustion. Clearly there are many photons exiting stars every second, and each star is losing large amounts of matter in the form of photons. In addition, the most popular theory explains that most atoms heavier than Hydrogen and no heavier than Iron are made in stars, and atoms larger than iron can only be made in supernovae.
5,000,000,000 YBN	22) Heavier atoms in the star system move closer to the center and lighter atoms are sent farther out.
4,600,000,000 YBN	17) Planets form around star. Terrestrial planets are red hot, have surface of melted rock, all lighter atoms float to the surface of the molten planets. All the H2O from the first earth oceans and lakes is in the atmosphere in gas form.
	30) Moon of earth is formed by 1 of 3 ways: 1) spherical planet collides with earth, moon forms from remaining matter in ring around earth. 2) spherical planet is caught in earth orbit 3) moon of earth forms naturally from original matter of star system in orbit around earth.
4,571,000,000 YBN	31) Oldest meteorite yet found on earth 4,571 million years old.
4,530,000,000 YBN	33) Oldest Moon rock returned from Apollo missions (4.53 billions old).
4,500,000,000 YBN	24) Oldest meteor and moon (although no earth) rocks date from this time 4.5 billion years before now.
LIFE
	50) Start Precambrian Eon, Hadean Era.
4,450,000,000 YBN	21) Planet earth cools, molten rock cools into thin crust, H2O condenses from the atmosphere by raining, filling the lowest parts of land to make the first earth oceans, lakes, and rivers.
4,404,000,000 YBN	34) Oldest ''terrestrial'' (not from meteorite) zircon yet found on earth, 4.404 billion years old, from Gneiss in West Australia, is evidence that the crust and liquid water were on the surface of earth 4.4 billion years before now.
4,400,000,000 YBN	18) Amino acids, phosphates, and sugars, the components of living objects are created on earth. These molecules are made in the oceans, fresh water, and or atmosphere of earth (or other planets) by lightning, photons with ultraviolet frequency from the star, or ocean floor volcanos.
4,395,000,000 YBN	19) How nucleic acids (polymers made of nucleotides), proteins (polymers made of amino acids), carbohydrates (polymers made of sugars) and lipids (glycerol attached to fatty acids) evolved is not clearly known. Some proteins and nucleic acids have been formed in labs by using clay which can dehydrate and which provides long linear crystal structures to build proteins and nucleic acids on. Amino acids join together to form polypeptides when an H2O molecule is formed from a Hydrogen (H) on 1 amino acid and a hydroxyl (OH) on the second. Are all proteins, carbohydrates, lipids and DNA the products of living objects? Is RNA the only molecule of these that was made without the help of living objects? The most popular theory now has RNA (and potentially lipids) evolving first before any living objects. There is still a large amount of experiment, exploration and education that needs to be done to understand the origins of living objects on planet earth. My opinion is that as soon as there was liquid water on the earth, 4.4 billion years before now, as zircon crystals show, the construction of living objects started on earth.
4,390,000,000 YBN	25) RNA duplication evolves. Perhaps RNA molecules, called ''ribozymes'' evolved which can make copies of RNA, by connecting free floating nucleotides that match a nucleotide on the same or a different RNA, without any proteins. But until such ribozyme RNA molecules are found, the only molecule known to copy nucleic acids are proteins called polymerases. If such ribozymes exist, then one of the first coded instructions on the RNA molecule that was the ancestor of every living species, must have been the code to make this ribozyme. These early RNA molecules may have been protected by liposomes (spheres of lipids). This process of RNA (and then later DNA) duplication is the most basic aspect of life on earth, and for all the diversity, the one common element of all life is this constant process of DNA duplication, which will later evolve to include cell division. This starts the unbroken thread of copying and division that connects the earliest ancestor, some RNA molecule, to all life on earth that has ever lived.
4,385,000,000 YBN	167) Protein assembly evolves with the creation of various Transfer RNA (tRNA) molecules. Random mutations in the copying (and perhaps even in the natural formation) of RNA molecules probably created a number of the necessary tRNAs (transfer RNA, an RNA molecule responsible for matching free floating amino acid molecules to 3 nucleotide sequences on other RNA molecules). This would be a precellular protein assembly system, where tRNA (transfer RNA) molecules can build polypeptide chains of amino acids by linking directly to other RNA strands. Part of each tRNA molecule bonds with a specific amino acid, and a 3 nucleotide sequence from a different part of the tRNA molecule bonds with the opposite matching 3 nucleotide sequence on an (m)RNA molecule. Since there are tRNA molecules for each amino acid (although some tRNAs can attach to more than one amino acid?), there must have been a slow accumulation of various tRNA molecules for each of the 20 amino acids used in constructing polypeptides in cells living now. Perhaps after the evolution of the first tRNA, the first polypeptides were chains of all the same one amino acid. With the evolution of a second tRNA polypeptides would have more variety because now two amino acids would be available to build polypeptides. This polypeptide assembly system may exist freely in water, or within a liposome. This sytem builds many more proteins than would be built without such a system. The mRNA with the code to make copier RNA, now also contains the code to produce various tRNA molecules. These molecules function as a unit, and proto-cell, with the rest of the mRNA initially containing random codes for random proteins. For the first time, RNA code represents a template for other RNA molecules, but also a template for building proteins with the help of tRNA molecules. There is some question of where the origin of the first cell took place, near volcanos on the ocean floor, or in fresh water lakes and tidal pools near volcanos on land, because unprotected nucleic acids cannot exist for much time in the ocean because of Sodium and Chlorine. What were the first amino acids connected as proteins? Were the first proteins all made with the same amino acid?
4,380,000,000 YBN	168) Ribosomal RNA (rRNA) evolves. Ribosomal RNA moves down mRNA molecules functioning as a platform for bringing the mRNA and tRNA molecules together to assemble polypeptides (proteins). This rRNA serves as an early ribosome; objects that serve as sites for building polypeptides and are found in every cell. As time continues the ribosome will grow to include two more RNA molecules, some protein molecules, and a second half that will make polypeptide construction more efficient. The rRNA serves the purpose of bringing amino acids close enough to bond with each other to form polypeptides. As an rRNA moves down an mRNA, tRNA molecules bond with the mRNA and on the opposite side of the tRNA, a matching amino acid (separates? from the tRNA and) attaches to a growing polypeptide chain. Now the mRNA that is the ancestral/progenitor of all of life, contains the code for the copier RNA, tRNAs, and the rRNA molecule. These nucleic acids function as a unit, and proto-cell.
4,375,000,000 YBN	211) The first protein of real importance is built, an RNA polymerase. A molecule that can more efficiently copy RNA. The first protein of real importance is evolved by RNA and assembled by the early ribosome, an RNA polymerase. A molecule that can more efficiently copy RNA.
4,370,000,000 YBN	41) A ribonucleotide reductase protein is built by the early ribosome protein making protocell. This protein changes ribonucleotides into deoxyribonucleotides. This allows the first DNA molecule on earth to be assembled. Ribonucleotide reductase may be the molecule that allowed DNA to be the template for the line of cells that survived to now.
4,365,000,000 YBN	212) A DNA polymerase protein evolves to copy DNA by assembling DNA nucleotides from other DNA molecules.
4,360,000,000 YBN	166) An RNA molecule evolves that causes the early ribosome to create reverse transcriptase, a protein that can assemble DNA molecules from an RNA molecule template. With this advance, a DNA molecule can be constructed that has all of the code that was stored on the long evolved RNA molecule. DNA now serves as a more stable template for making mRNA, each tRNA, rRNA, and the RNA and DNA polymerases. RNA polymerase proteins build RNA molecules using the new DNA template, that still perform their original polypeptide building function together with the tRNA and rRNA molecules, but are labeled ''mRNA'' (Messenger RNA) because they move from DNA to ribosome. Why DNA serves as the template for all cells and not mRNA is not fully understood, but DNA is a more stable molecule than the single stranded RNA. Perhaps the 2 legs of DNA serve some other important reasons, for example, two legs may allow two processes to happen at one time.
4,355,000,000 YBN	20) The first cell membrane evolves around DNA, made of proteins. This membrane holds water inside a cell. This is the first cell. rRNA comparison shows that this is most likely a eubacterium. DNA produces instructions for cytoplasm, the cytoplasm is assembled from proteins made by the ribosome. For the first time, DNA and ribosomes are building cell structure. The templates for each tRNA, rRNA, mRNA and DNA polymerase proteins are already coded in a central strand of DNA. DNA protected by cytoplasm is more likely to survive and copy. This cell is heterotrophic and has no metabolism to produce ATP. Amino acids, nucleotides, H2O, and other molecules enter and exit the cytoplasm only because of a difference in concentration from inside and outside the cell (passive transport) and represent the beginnings of the first digestive system. This either happens in fresh water lakes or in salty oceans, perhaps near lava vents on or under the ocean floor. As this line of DNA continues to make copies of itself, all copies now have cytoplasm. The DNA is composed mainly of instructions to assemble the nucleic acids and proteins needed to build ribosomes, polymerases and cytoplasm. This cell structure forms the basis of all future cells of every living object on earth. These first cells are anaerobic (do not require free oxygen) and heterotrophic, meaning that they do not make their own food: amino acids, nucleotides, phosphates, and sugars. These bacteria depend on these molecules and photons in the form of heat to reproduce and grow. A system of division must evolve which attaches the original and newly synthesized copy of DNA to the cytoplasm, so that as the cell grows, the two copies of DNA can be separated and the first membraned cells can divide into two cells. This is the beginning of the ''binary fission'' method of cell division. Division of the cell begins with the division of the DNA membrane-attachment site and separates by the growth of new cytoplasm. DNA has 2 functions, 1) to be copied by the polymerase protein, 2) to serve as a code for assembling proteins. Two important evolutionary steps evolve: DNA duplication in cytoplasm, and cell (DNA with cytoplasm) division. The process of DNA duplication is probably similar if not the same process using the same proteins that were used to duplicate DNA without cytoplasm.
4,350,000,001 YBN	26) Perhaps DNA that is connected in a circle allows the DNA polymerase to make continuous copies of the cell. In theory prokaryote cells do not deteroiate from the effect of aging, but they do endure mutations (from photons with ultraviolet frequency, for example), however, there are many other ways prokaryotes can be destroyed (loss of water, physically damaged by nonliving objects, eaten by other organisms, and other mechanisms).
4,345,000,000 YBN	195) Proteins that actively transport molecules into and out of the cytoplasm (facilitative diffusion) evolve.
4,340,000,000 YBN	23) The first viruses are made either from bacteria, or are initially bacteria. These cells depend on the DNA duplicating and protein producing systems of other cells to reproduce themselves. Over time, more effective, and efficient virus designs will survive.
4,335,000,000 YBN	28) Glycolysis evolves in the cytoplasm. Cells can now make ATP from glucose and eventually other monosaccharides, the end product is pyruvate. The glycolysis equation is: C6H12O6 (glucose) + 2 NAD+ + 2 ADP + 2 P -----> 2 pyruvic acid, (CH3(C=O)COOH + 2 ATP + 2 NADH + 2 H+
4,330,000,000 YBN	44) Fermentation evolves in the cytoplasm. Cells (all anaerobic) can now make more ATP and convert pyruvate (the final product of glycolysis) to lactate (an ionized form of lactic acid).
4,325,000,000 YBN	213) A second kind of fermentation evolves in the cytoplasm. Cells (all anaerobic) can now convert pyruvate (the final product of glycolysis) to ethanol.
4,320,000,000 YBN	183) Cells evolve that make proteins that can assemble lipids.
4,315,000,000 YBN	196) Cells that use both proteins and metabolism (ATP) to transport molecules into and out of the cytoplasm (active transport) evolve.
4,310,000,000 YBN	40) One of the first useful proteins to be created with an early precellular protein production system must have been a protein (like RNA polymerase) that can make copies of RNA from mRNA molecules. This protein may have outperformed a ribozyme that was performing the copying function. Eventually mRNA that coded for tRNA molecules and mRNA that coded for rRNA molecules merged to form a template. Now the entire protein production system (the mRNA itself, tRNAs, rRNAs, and the RNA polymerase) could be copied many times by the RNA polymerase protein. This is before cytoplasm or any cell wall has evolved. RNA and DNA copying happens in water, the first cell has not evolved yet.
	76) Pili, plasmids and conjugation evolves in prokaryotes. Now some prokaryotes can exchange circular pieces of DNA (plasmids), through tubes (pili). Conjugation may be the process that led to sex (cellular fusion) and also the transition from a circle of DNA to chromosomes in eukaryotes, since some protists (cilliates and some algae) reproduce sexually by conjugation. Archaeal flagellins are related to members of the type IV pilin/transport superfamily widespread in bacteria. In addition to pili and conjugation, proteins evolve that can assist in splitting DNA and also proteins that assist in merging two strands of DNA together, since some times the DNA in split and the new plasmid is connected and the DNA circle is sown back together.
4,307,000,000 YBN	292) Prokaryote flagella evolve. Perhaps pili evolved into flagella, flagella into pili, or the two systems are unrelated. Proteins in Archaebacteria flagella are related to pili in bacteria. This may be the beginning of motility. Now for the first time, cells are not completely controlled by surrounding matter, but can make limited choices about their location.
4,305,000,000 YBN	64) Operons, sequences of DNA that allow certain proteins coded by DNA to not be built, evolve. Proteins bind with these DNA sequences to stop RNA polymerase from building mRNA molecules which would be translated into proteins. Operons allow a bacterium to produce certain proteins only when necessary. Bacteria before now can only build a constant stream of all proteins encoded in their DNA.
4,304,500,000 YBN	322) Nitrogen fixation evolves in eubacteria. Without bacteria that convert N2 into nitrogen compounds, the supply of nitrogen necessary for much of life would be seriously limited and would drastically slow evolution on earth. Nitrogen fixation is the process by which nitrogen is taken from its relatively inert molecular form (N2) in the atmosphere and converted into nitrogen compounds useful for other chemical processes (such as, notably, ammonia, nitrate and nitrogen dioxide). Nitrogen fixation is performed naturally by a number of different prokaryotes, including bacteria, and actinobacteria certain types of anaerobic bacteria. Many higher plants, and some animals (termites), have formed associations with these microorganisms.
4,304,000,000 YBN	287) Multicellularity in the form of filment growth evolves in prokaryotes. Cyanobacteria grow in filaments. Unlike eukaryotes, there is no communication between cells in prokaryote filments.
4,302,000,000 YBN	316) Cell differentiation in prokaryotes evolve. Heterocysts evolve in cyanobacteria. Heterocysts are specialized nitrogen-fixing cells formed by some filamentous cyanobacteria during nitrogen starvation. What cell differentiation is first is unknown, perhaps cells that form spores, or cysts, or perhaps cell differentiation that is observes in cyanobacterial filamentous cells. Heterocysts are specialized nitrogen-fixing cells formed by some filamentous cyanobacteria, such as Nostoc punctiforme and Anabaena sperica, during nitrogen starvation. They fix nitrogen from dinitrogen (N2) in the air using the enzyme nitrogenase, in order to provide the cells in the filament with nitrogen for biosynthesis. Nitrogenase is inactivated by oxygen, so the heterocyst must create a microanaerobic environment. The heterocysts' unique structure and physiology requires a global change in gene expression. For example, heterocysts: * produce three additional cell walls, including one of glycolipid that forms a hydrophobic barrier to oxygen * produce nitrogenase and other proteins involved in nitrogen fixation * degrade photosystem II, which produces oxygen * up regulate glycolytic enzymes, which use up oxygen and provide energy for nitrogenase * produce proteins that scavenge any remaining oxygen Cyanobacteria usually obtain a fixed carbon (carbohydrate) by photosynthesis. The lack of photosystem II prevents heterocysts from photosynthesising, so the vegetative cells provide them with carbohydrates, which is thought to be sucrose. The fixed carbon and nitrogen sources are exchanged though channels between the cells in the filament. Heterocysts maintain photosystem I, allowing them to generate ATP by cyclic photophosphorylation. Single heterocysts develop about every 9-15 cells, producing a one-dimensional pattern along the filament. The interval between heterocysts remains approximately constant even though the cells in the filament are dividing. The bacterial filament can be seen as a multicellular organism with two distinct yet interdependent cell types. Such behaviour is highly unusual in prokaryotes and may have been the first example of multicellular patterning in evolution. Once a heterocyst has formed, it cannot revert to a vegetative cell, so this differentiation can be seen as a form of apoptosis. Certain heterocyst-forming bacteria can differentiate into spore-like cells called akinetes or motile cells called hormogonia, making them the most phenotyptically versatile of all prokaryotes. The mechanism of controlling heterocysts is thought to involve the diffusion of an inhibitor of differentiation called PatS. Heterocyst formation is inhibited in the presence of a fixed nitrogen source, such as ammonium or nitrate. The bacteria may also enter a symbiotic relationship with certain plants. In such a relationship, the bacteria do not respond to the availability of nitrogen, but to signals produced by the plant. Up to 60% of the cells can become heterocysts, providing fixed nitrogen to the plant in return for fixed carbon. The cyanobacteria that form heterocysts are divided into the orders Nostocales and Stigonematales, which form simple and branching filaments respectively. Together they form a monophyletic group, with very low genetic variability.
4,300,000,000 YBN	58) First autotrophic cells, cells that can produce some if not all of their own food (amino acids, nucleotides, sugars, phophates, lipids, and carbohydrates), but require phosphorus, nitrogen, CO2, water and light in the form of heat. There are only 2 kinds of autotrophy: Lithotrophy and Photosynthesis. These are lithotrophic cells that change inorganic (abiotic) molecules into organic molecules. These cells are archaebacteria, called methanogens that perform the reaction: 4H2 + CO2 -> CH4 + 2H2O. They convert CO2 into Methane. Methane is better than CO2 for trapping heat, and could have contributed to heating the earth.
4,295,000,000 YBN	49) First photosynthetic cells. These cells only have Photosystem I. Photosynthesis Photosystem I evolves in early anaerobic prokaryote cells. One of two photosythesis systems, photosystem I uses a pigment chlorophyll A, absorbs photons in 700 nm wave lengths best, breaking the bond betwenn H2 and S. They are anaerobic and perform the reaction: H2S (Hydrogen Sulfide) + CO2 + light -> CH2O (Formaldehyde) + 2S. Only 5 phyla of eubacteria can photosynthesize.
4,290,000,000 YBN	43) Photosynthesis Photosystem II evolves in early prokaryote cells. Photosystem 2 absorbs photons best at 680nm wavelengths, a higher frequency of light than Photosystem I. These cells can break the strong Hydrogen bonds between Hydrogen and Oxygen in water molecules (more abundant than Sulphur). This system emits free Oxygen. The simple equation of photosynthesis is: 6 H2O + 6 CO2 + photons = C6H12O6 (glucose) + 6O2. The detailed steps of photosynthesis are called the ''Calvin Cycle''. Prokaryote cells can now produce their own glucose to store and be converted to ATP by glycolysis and fermentation later. This sytem is the main system responsible for producing the Oxygen now in the air of earth. Of the 5 phyla of eubacteria that can photosynthesize, only 1, cyanobacteria, produces oxygen.
4,280,000,000 YBN	57) Cellular Respiration (also called the ''Citric Acid Cycle'', and the ''Krebs Cycle'') evolves, probably in cyanobacteria, as a substitute for fermentaton, by using oxygen to break down the products of glycolysis, pyruvic acid, to CO2 and H2O, producing 18 more ATP molecules. This is the first aerobic cell, a cell that has an oxygen based metabolism. This cell uses oxygen to convert glucose (and eventually other sugars and fats) into CO2, H2O and ATP. For example, cells that oxidize glucose perform the reaction: C6H12O6 + 6 O2 + 38 ADP + 38 phosphate -> 6 CO2 + 6 H2O + 38 ATP This reaction (with glycolysis) can produce up to 36 ATP molecules. Cellular respiration is the opposite (although the specific reactions differ) of photosynthesis which starts with H2O and CO2 and produces glucose. Steps are: Glycolysis preparatory phase Glycolysis pay-off phase Oxidative carboxylation Krebs cycle
4,260,000,000 YBN	27) DNA (or RNA) produces instructions for a cell wall. The cell wall only protects bacteria and does not filter any molecules as the cytoplasm does. is first gram-negative cell wall? 1. Only contain a few layers of peptidoglycan -- the building block for strong, rigid cell walls 2. Contain an outer membrane, external to the peptidoglycan, called the lipopolysaccharide 3. The space between the layers of peptidoglycan and the secondary cell membrane is called periplasmatic space 4. The S-layer is directly attached to the outer membrane, rather than the peptidoglycan 5. Any flagella, if present, have 4 supporting rings instead of two 6. No teichoic acids are present''
4,250,000,000 YBN	29) There are many proteins and secondary processes in cells that are not fully understood yet.
	42) More prokaryote cell fossils need to be found, more DNA needs to be sequenced, and more bacteria found and grown to fully understand when bacteria parts evolved. For example: flagella plasmids pili and ''conjugation'' the trade of pieces of plasmid DNA (this may be the earliest form of sex [or syngamy]) changing into spores When gram-stain positive cell walls evolved. When the various shapes evolved: spherical (coccus,cocci) rod (bacillus,bacilli) spiral (spirilla) other: short rods (coccobacilli). commas (vibrii). squares (rare) stars (rare) irregular (rare) Which specific bacteria of the Archaea (if any) were first, which of the Eubacteria and Cyanobacteria came next. When the ''Nitrogen Cycle'' or ''Nitrogen Fixing'' evolved. Few cells can separate N2 into N, [needed for nucleic acids?]. The waste product urea is converted by one bacteria to ammonia, a second bacteria converts the ammonia to N2.
	77) There are many widely varying estimates of when the first Eubacteria and Archaea evolved. Eubacteria and Archaea (also called Archaebacteria) are the two major lines of Prokaryotes. Prokaryotes are the most primitive living objects ever found. In contrast to the later evolved Eukaryotes, Prokaryotes have a circle of DNA located in their cytoplasm (not chromosomes) and have no nucleus. At least one genetic comparison shows Eubacteria and Archaea evolving now. After the full genomes of all living species are known, and understood we will have more certainty about the history of evolution. Many genetic trees are based on DNA genes (sequences of DNA that define nucleic acids or proteins). In particular the genes for ribosomal RNA are thought to be very conserved over time, although perhaps genes for reproduction, or cytoplasm, for example may later prove to be more conserved over time. Only when the full genomes of all living species are known, and understood will we have strong certainty about the history of evolution. Many genetic trees are based on DNA genes (sequences of DNA that define nucleic acids or proteins), in particular ribosomal RNA which is thought to be highly conserved over the eons of time. Ribosomal RNA may be the best record of evolutionary history, but perhaps other genes, for example, those involved with reproduction, or cytoplasm will prove to be more conserved or better estimates of evolutionary history. For example, I think the method of reproduction would be the most conserved, since that process is the most necessary for survival, changes to those genes may stop continued existence, where changes to rrna may not be as serious. In addition, the vast diversity and change in reproductive method over time, should tell us that similar large scale changes could have happened for rrna, cytoplasm, and indeed any part of a cell. These early Archaea and Eubacteria are ''thermophile'' bacteria, bacteria that are found and grow best in hot water (80+ degrees Celsius). That genetic evidence puts these prokaryotes as the oldest living prokaryotes is evidence that the first prokaryotes on earth may have lived in hot water, perhaps near thermal springs or near ocean floor volcanos. Perhaps the water on the early earth was hot when these first prokaryotes evolved.
4,112,000,000 YBN	180) The Archaea Phylum, Euryarchaeotes evolve. Genetic comparison shows the Archaea Phylum, Euryarchaeotes evolving now. The Euryarchaeota are a major group of Archaea. They include the methanogens, which produce methane and are often found in intestines, the halobacteria, which survive extreme concentrations of salt, and some extremely thermophilic aerobes and anaerobes. They are separated from the other archaeans based mainly on rRNA sequences. Euryarchaeota may contain the most ancient DNA of any living object on earth.
	181) The Archaea Phylum, Crenarchaeotes evolves. Genetic comparison shows Archaea Phylum, Crenarchaeotes evolving now. The phylum Crenarchaeota, commonly referred to as the crenarchaea, in the domain Archaea, contains many extremely thermophilic and psychrophilic organisms. They were originally separated from the other archaeons based on rRNA sequences, since then physiological features, such as lack of histones have supported this division. Until recently all cultured crenarchaea have been thermophilic or hyperthermophilic organisms, some of which have the ability to grow up to 113 degrees C. These organisms stain gram negative and are morphologically diverse having rod, cocci, filamentous and unusually shaped cells.
4,030,000,000 YBN	35) Metamorphic rock, a Gneiss near Acasta and Great Slave Lake in the North West territories of Canada dates from this time, 4030 million years before now.
3,977,000,000 YBN	193) Eubacteria ''Hyperthermophiles'' (Aquifex, Thermotoga, etc.) evolve now. Genetic comparison shows that Eubacteria ''Hyperthermophiles'' (Aquifex, Thermotoga, etc.) evolve now. This may be the living object with the most primitive DNA found on earth (depending on the age of the archaea). This group of eubacteria includes the Phyla ''Aquificae'', ''Thermodesulfobacteria'', and ''Thermotogae''. The Aquificae phylum is a diverse collection of bacteria that live in harsh environmental settings. They have been found in hot springs, sulfur pools, and thermal ocean vents. Members of the genus Aquifex, for example, are productive in water between 85 to 95 �C. They are the dominant members of most terrestrial neutral to alkaline hot springs above 60 degrees celsius. They are autotrophs, and are the primary carbon fixers in these environments. They are true bacteria (domain eubacteria) as opposed to the other inhabitants of extreme environments, the Archaea. Thermotoga are thermophile or hyperthermophile bacteria whose cell is wrapped in an outer ''toga'' membrane. They metabolize carbohydrates. Species have varying amounts of salt and oxygen tolerance. Thermotoga subterranea strain SL1 was found in a 70�C deep continental oil reservoir in the East Paris Basin, France. It is anaerobic and reduces cystine and thiosulfate to hydrogen sulfide.
3,850,000,000 YBN	36) The oldest sediment on earth is also the oldest Banded Iron Formation, on Akilia Island in Western Greenland. The oldest evidence for life on earth was found in this rock by measuring the ratio of carbon 12 to carbon 13 in grains of apatite (calcium phosphate) from this rock. Life uses the lighter Carbon-12 isotope and not Carbon-13 and so the ratio of carbon-12 to carbon-13 is different from a nonliving source (calcium carbonate or limestone).
	45) This marks the beginning of the Banded Iron Formation Rocks. These rocks are sedimentary. They are made of iron rich chert (silicates, like SiO2). These rocks have alternative bands of orange or yellow and black. In the red parts the iron is oxydized (contains iron oxides, either hematite [Fe2O3 = rust] or magnetite [Fe3O4]). These bands may have formed because photosynthetic bacteria (in stromatolites found in shallow ocean shores, and purple bacteria floating in water) produce oxygen from CO2 during photosynthesis. When the level of oxygen in the water became too high, many bacteria died, and this cycle created the BIF. But BIF also may form naturally when photons in uv frequencies split H2O into H2 and O2. So perhaps the BIF bands represent cycles of more or less uv light reaching the earth. Perhaps the alternating phenomenon is similar to eukaryotic algal blooms. In any event, this free oxygen bonded with the many tons of iron dissolved in the water to form insoluable iron oxide which then fell to the ocean floor to form the orange layers of Banded Iron Formation. How these alternating bands are made is not clear and has not yet been duplicated in a lab. This cycle of alternating orange and black bands will continue for 2 billion years until 1,800 million years before now. This is the beginning of oxygen production on earth, the atmosphere of earth still has only small amounts of oxygen at this time. It is amazing that people are still not certain what was the cause of the oxygen, and the cycles that deposited the banded Iron Formation.
	189) Fossils from Isua Banded iron formation, SW Greenland.
3,800,000,000 YBN	51) End Hadean Era, start Archean Era.
	185) Isoprene compounds from Isua, Greenland Banded Iron Formation sediment are evidence of the existence of Archaea.
3,760,000,000 YBN	186) Sulfur isotope ratios (34S/32S) and Hydrocarbon molecules (alkanes) detected in 3760 billion year old Isua Banded Iron Formation, indicate the possibility of photosynthetic sulfate reducing bacteria (Archaea, for example Sulpholobus) and Cyanobacteria living at that time.
3,700,000,000 YBN	184) Amount of Uranium isotope measured in Isua, Greenland Banded Iron Formation evidence of prokaryote Oxygen photosynthesis.
	215) C13/C12 ratio of 3700+ MYO sediment in Australia shown to be consistent with planktonic photosynthesizing organisms.
3,566,000,000 YBN	78) Genetic comparison shows Archaebacteria (Archaea) Phylum, Korarchaeotes evolving now.
3,500,000,000 YBN	37) The oldest fossil evidence of life yet found. Stromatolites made by photosynthetic bacteria found in both Warrawoona, Western Australia, and Fig Tree Group, South Africa.
	39) Oldest fossils of an organism, thought to be cyanobacteria, found in 3,500 Million Year old chert from South Africa and 3,465 Million year old Apex chert of north-western Australia. Oldest fossils of an organism, thought to be cyanobacteria, found in 3,500 Million Year old chert from South Africa and 3,465 Million year old Apex chert of the Pilbara Supergroup, Warrawoona Group, northwestern Western Australia. Some people argue that these are not fossils of bacteria but abiotic material. Most genetic timelines put the origin of cyanobacteria much later around 2,700mybn.
3,470,000,000 YBN	182) Sulphate fossil molecular marker evidence of moderate thermophile sulphur reducing prokaryotes from North Pole, Australia.
	216) Evidence of sulphate reduction by bacteria.
3,416,000,000 YBN	218) Fossil and molecular evidence of photosynthetic, probably anoxygenic, bacteria that lived in mats in the ocean date to this time.
3,400,000,000 YBN	190) Fossils from Kromberg Formation, Swaziland System, South Africa.
3,260,000,000 YBN	71) Budding evolves in prokayotes. Different from binary division, where a cell is split in half, in budding, a new complete cell is made in the original cell, and the new cell bursts through the cell wall, the original cell wall must then be repaired. Budding is the only other method of reproduction known in prokaryotes besides binary fission. The only major difference between prokaryote budding and binary division are that one or more new cells are completely formed inside the original cell, where in binary division part of the original cell wall is used to make the new cell. In budding, a complete new cell is synthesized from a DNA template, where in binary division only the DNA is duplicated and more cytoplasm and cell wall is synthesized. So, budding preserves organelles made by the main DNA template that cannot duplicate themselves and would not get duplicated or synthesized in binary division, for example, flagella.
3,250,000,000 YBN	191) Fossils from Swartkoppie chert, South Africa are oldest evidence of procaryotes that reproduce by budding and not binary fission.
3,235,000,000 YBN	68) Thermophilic prokaryote fossils found in 3235 million year old deep-sea volcanogenic massive sulphide deposits from the Pilbara Craton of Australia may be oldest Archaea fossils.
2,923,000,000 YBN	178) Eubacteria Phylum Firmicutes (low G+C [Guanine and Cytosine count] Gram positive) evolve. Genetic comparison shows Eubacteria Phylum Firmicutes (low G+C [Guanine and Cytosine count] Gram positive) evolving here. Firmicutes include the Classes: Bacillus (anthrax), Listeria, Mollicutes, and Stephylococcus. Firmicutes may be the first rod shaped bacteria, and first bacteria to have a gram positive cell wall. The peptidoglycan layer is thicker in Gram-positive bacteria (20 to 80 nm) than in Gram-negative bacteria (7 to 8 nm) Firmicultes form endospores, and is the only phlyum of bacteria that evolved the ability to build endospores.
2,920,000,000 YBN	288) Eubacteria firmicutes evolve the abililty to form endpospores.
2,800,000,000 YBN	177) Genetic comparison shows the ancestor of all Proteobacteria (Rickettsia [mitochondria], gonorrhoea, Salmonella, E coli) evolving now. Proteobacteria include 5 Classes: CLASS Alpha Proteobacteria (Rickettsia Prowazekii [mitochondria/typhus]) CLASS Beta Proteobacteria (Neisseria gonorrhoeae [gonorrhoea]) CLASS Gamma Proteobacteria (Salmonella and Escherichia coli.) CLASS Delta Proteobacteria CLASS Epsilon Proteobacteria The Proteobacteria are a major group of bacteria. They include a wide variety of pathogens, such as Escherichia, Salmonella, Vibrio, Helicobacter, and many other notable genera. Others are free-living, and include many of the bacteria responsible for nitrogen fixation. The group is defined primarily in terms of ribosomal RNA (rRNA) sequences, and is named for the Greek god Proteus, who could change his shape, because of the great diversity of forms found in it. All Proteobacteria are Gram-negative, with an outer membrane mainly composed of lipopolysaccharides. Many move about using flagella, but some are non-motile or rely on bacterial gliding. The last include the myxobacteria, a unique group of bacteria that can aggregate to form multicellular fruiting bodies. There is also a wide variety in the types of metabolism. Most members are facultatively or obligately anaerobic and heterotrophic, but there are numerous exceptions. A variety of genera, which are not closely related, can photosynthesize. These are called purple bacteria, referring to their mostly reddish pigmentation. The delta-proteobacteria Myxobacteria is capable of colonial multicellularity and some view as possibly being the bacteria that formed the cytoplasm in eukaryotes.
2,784,000,000 YBN	176) Genetic comparison shows Eubacteria Phylum, Planctomycetes (Planctobacteria) evolving now. Planctomycetes are a possible ancestor of all eukaryotes because the circle of DNA can sometimes be enclosed in a double membrane. Planctomycetes is a small phylum with only 4 Genera, require oxygen for growth (obligately aerobic), are found in fresh and salt water. They reproduce by budding. They have holdfast (stalk) at the nonreproductive end that helps them to attach to each other during budding. The life cycle involves alternation between sessile cells and flagellated swarmer cells. The sessile cells bud to form the flagellated swarmer cells which swim for a while before settling down to attach and begin reproduction. It is also possible, although unlikely, that planctomycetes are descended from a very early eukaryote that lost the nucleus but retained the cytoplasmic DNA, since budding may have evolved as a method to duplicate a eukaryote cell from the nucleus. (ok this is out there...maybe t3)
	179) Genetic comparison shows Eubacteria Phylum, Actinobacteria (high G+C, Gram positive) evolving now. Actinobacteria have 5 Orders: ORDER Acidimicrobiales ORDER Actinobacteriales ORDER Coriobacteriales ORDER Rubrobacteriales ORDER Sphaerobacteriales Actinobacteria include the causes of tuberculosis (Mycobacteria tuberculosis) and leprosy (Mycobacteria leprae). The Actinobacteria or Actinomycetes are a group of Gram-positive bacteria. Most are found in the soil, and they include some of the most common soil life, playing an important role in decomposition of organic materials, such as cellulose and chitin. This replenishes the supply of nutrients in the soil and is an important part of humus formation. Other Actinobacteria inhabit plants and animals, including a few pathogens, such as Mycobacterium.
2,775,000,000 YBN	174) Genetic comparison shows Eubacteria Phylum, Spirochaetes (Syphilis, Lyme disease) evolving now. Includes leptospirosis (leptospira), Lyme disease (Borrelia burgdorferi), and Syphilis (Treponema pallidum). Spirochaetes only have one order: ORDER Spirochaetales This is when the first spiral shaped bacteria evolve. The spirochaetes (or spirochetes) are a phylum of distinctive bacteria, which have long, helically coiled cells. They are distinguished by the presence of flagella running lengthwise between the cell membrane and cell wall, called axial filaments. These cause a twisting motion which allows the spirochaete to move about. Most spirochaetes are free-living and anaerobic, but there are numerous exceptions.
	175) Genetic comparison shows Eubacteria Phyla Bacteroidetes and Chlorobi (green sulphur bacteria) evolving now. PHYLUM Bacteroidetes CLASS Bacteroides ORDER Bacteroidales CLASS Flavobacteria ORDER Flavobacteriales CLASS Sphingobacteria ORDER Sphingobacteriales PHLYUM Chlorobi (Green sulphur) CLASS Chlorobia ORDER Chlorobiales The phylum Bacteroidetes is composed of three large groups of bacteria. By far, more is written about and known about the Bacteroides class, than the other two, the Flavobacteria and the Sphingobacteria classes. They are related by the similarity in the composition of the small 16S subunit of their ribosomes. Members of the bacteroides class are human commensals (they benefit but humans receive no effect) and sometimes pathogens. Members of the other two classes are rarely pathogenic to humans. Chlorobi are the ''green sulphur bacteria'', are a family of phototrophic (photosynthesizing) bacteria. Green sulfur bacteria are generally nonmotile (one species has a flagellum), and come in spheres, rods, and spirals. Their environment must be oxygen-free, and they need light to grow. They engage in photosynthesis, using bacteriochlorophylls c, d, and e in vesicles called chlorosomes attached to the membrane. They use sulfide ions as electron donor, and in the process the sulfide gets oxidized, producing globules of elemental sulfur outside the cell, which may then be further oxidized. (By contrast, the photosynthesis in plants uses water as electron donor and produces oxygen.) A species of green sulfur bacteria has been found living near a black smoker off the coast of Mexico at a depth of 2,500 meters beneath the surface of the Pacific Ocean. At this depth, the bacteria, designated GSB1, lives off the dim glow of the thermal vent since no sunlight can penetrate to that depth.
	217) Genetic comparison shows Eubacteria Phyla Chlamydiae and Verrucomicrobia evolving now. Chlamydiae includes (clamydia, trachoma [Chlamydia trachomatis], a form of pneumonia [Chlamydophila pneumoniae], psittacosis [Chlamydophila psittaci]. CLASS Chlamydiae ORDER Chlamydiales PHYLA Verrucomicrobia ORDER Verrucomicrobiales The Chlamydiae are a group of bacteria, all of which are intracellular parasites of eukaryotic cells. Most described species infect mammals and birds, but some have been found in other hosts, such as amoebae. Chlamydiae have a life-cycle involving two distinct forms. Infection takes place by means of elementary bodies (EB), which are metabolically inactive. These are taken up within a cellular vacuole, where they grow into larger reticulate bodies (RB), which reproduce. Ultimately new elementary bodies are produced and expelled from the cell. Verrucomicrobia is a recently described phylum of bacteria. This phylum contains only a few described species (Verrucomicrobia spinosum, is an example, the phylum is named after this). The species identified have been isolated from fresh water and soil environments and human feces. A number of as-yet uncultivated species have been identified in association with eukaryotic hosts including extrusive explosive ectosymbionts of protists and endosymbionts of nematodes residing in their gametes. Evidence suggests that verrucomicrobia are abundant within the environment, and important (especially to soil cultures). This phylum is considered to have two sister phyla Chlamydiae and Lentisphaera.
2,760,000,000 YBN	80) Endocytosis, a process where the cell membrane folds around some molecules to form a spherical vesicle which enters the cytoplasm, and exocytosis, the opposite process, where a vesicle combines with a call membrane to empty molecules outside a cell both evolve in an early eukaryote cell. Eukaryote cells can now swallow bacteria (phagocytosis) and liquid (pinocytosis). The cells can then (heterotrophically) use the molecules injested (for example a bacterium) for copying and to make ATP. This is the first time one cell can eat a different living cell. How similar endocytosis is to conjugation is unknown at this time.
2,750,000,000 YBN	207) Cytoskeleton evolves in eukaryote cytoplasm. One theory is that the cytoskeleton formed from the eukaryote flagella (cilia, undulipodia) tubules. Cytoskeleton is a single body with the endoplasmic reticulum and nuclear membrane?
2,725,000,000 YBN	60) First eukaryotic cell evolves. This cell has a nucleus, with either single strands or a circle of DNA inside. This is a single anaerobic cell. This is the first protist. This cell evolves either by: 1) two or more bacteria joined, one with flagella (perhaps a eubacteria) formed the nucleus, a second formed the cytoplasm outside the nucleus, eventually the code to build the entire cell including the instructions to build the symbiotic captured bacteria was included in the new nucleus, 2) the nucleus formed as part of the cytoplasm lattice, perhaps the outer wall folded in on itself creating a double membrane, or a membrane grew around the DNA (for example like planctobacteria) which provided more protection for the DNA from the movement and digestive activities of cytoplasm now without a rigid cell wall, 3) a bacteria with flagella that grew cytoplasm and a secondary cell wall outside the original cell wall, 4) a virus, 5) a DNA strand from conjugation with a different prokaryote stored in a vesicle. There are key features that are different from eukaryotes and prokaryotes: 1) Eukaryotes have a nucleus, prokaryotes do not. 2) DNA in eukaryotes is in the form of chromosomes, in prokaryotes the DNA is in a circle. 3) Eukaryotes can do endocytosis, fold their cell membrane around some external object and injest the object, prokaryotes can not. 4) Eukaryotes have a membrane lattice of proteins, actin and myacin, prokaryotes do not. 5) Eukaryotes have an endoplasmic reticulum and golgi body. 6) Eukaryotes reproduce asexually by dual binary division (both nucleus and cell divide by binary division), budding, or mitosis, prokaryotes reproduce by budding or binary division. If the nucleus is an engulfed prokaryote, this cell inherits the processes of nuclear DNA duplication and nucleus division (karyokinesis) from prokaryote binary division. Initially, both the nucleus and cell divide by binary division. Support for the nucleus forming from a prokaryote is that chromosomes in parabasalia and dinoflagellates remain permanently anchored to the nuclear membrane (envelope?) by the kinetochores, the same way prokaryote DNA anchors to the cell membrane (wall?) during cell division. A theory of an archaebacteria (perhaps an eocyte) forming the first eukaryote nucleus and a gram-negative eubacteria forming the cytoplasm of the first eukaryote is supported by genetic evidence. This cell reproduces asexually by either binary fission (both nucleus and cytoplasm) or budding, or sexually by conjugation or both cell and nuclei fully merging. If this cell has chromosomes, this is the first (haploid) organism with chromosomes. Perhaps a sperm-like flagellated prokaryote merged with an ovum-like prokaryote from the same or a different species, perhaps by the ovum opening a pilus and the sperm-like cell entering the pilus, and once inside opening a pilus through which the DNA from the two cells could merge. Many diplomonads look like sperm cells stuck in an ovum, with the still flagellated sperm forming the nucleus, and some diplomonads, for example, the oxymonad, Saccinobaculus reproduce sexually. An important evolutionary step had to evolve here, and that is the evolution of the prokaryote binary division system: 1) duplicating DNA in the cytoplasm, 2) separating the two copies of DNA, and 3) the division of cytoplasm into two cells to an adapted process of eukaryote cell division: 1) duplicating DNA in the nucleus, 2) separating the DNA in the nucleus, 3) dividing the nucleus into two nuclei, 4) separating the two nuclei, and then 5) dividing the cytoplasm into two cells. It appears in early eukaryote nuclei (as seen in closed mitosis, where the nuclear membrane persistes through mitosis) that the nuclei divide by a process similar to binary division (as opposed to budding), which adds to the support for the first nucleus being a prokaryote and continuing to divide by binary division. Most people accept that the centrioles from which grow the microtubule spindles that pull apart chromosomes in mitosis, evolved from the base pairs which originally were, and on some species still are, connected to a cilium. Perhaps there are some eukaryote nuclei that duplicate by budding, although this has never been found to my knowledge. If ever found, that would imply that budding evolved before the first eukaryote, but could have possibly evolved after by simply dropping the instructions to copy anything other than the nucleus. Binary cell division in the most basic form only synthesizes more cytoplasm and cell wall, where budding reproduces the entire body plan of a cell (or nucleus in this case).
	65) DNA in the nucleus changes from a single circular chromosome to linear chromosomes. Possibly the prokaryote ancestor of the first eukaryote had linear chromosomes since some prokaryotes (although very few) are known to have linear chromosomes instead of or in addition to a single circular chromosome. Perhaps a DNA strand entered a cell by conjugation, the circle of DNA was cut to insert the new DNA (plasmid), but the new DNA strand was not sewn back into the original strand of DNA creating two strands of DNA which eventually evolved into the first 2 chromosomes. Perhaps the first eukaryote nucleus was a virus, many of which have linear chromosomes. This includes the evolution of histones, proteins which are packed in between nucleotides in each chromosome. Presumably DNA duplication (sythesis) of chromosomes (in the nucleus) is initially identical to DNA duplication of DNA strands or circular DNA. Some prokaryotes do not have just one circle of DNA. Brucella melitensis has 2 circlular chromosomes. Agrobacterium tumefaciens has a circular and a linear chromosome. Streptomyces griseus can have one linear chromosome. Borrelia burgdorferi contains a linear chromosome and a number of variable circular and linear plasmids. Most eukaryote orgenelles have a single circular chromosome except for the mitochondria of most cnidarians and some other forms which have linear chromosomes.
2,720,000,000 YBN	208) A eukaryote flagellum (cilium, undulipodium) evolves on early single cell eukaryotes. The eukaryote cilia (flagella, undulipodia) may evolve from a prokaryote flagella connected to the nucleus, from the cytoskeleten, or a symbiotic prokaryote. Cilia and eukaryote flagella are structurally the same, but have minor functional differences. Cilia are a special class of eukaryote flagella. The eukarote flagellum is different from prokayote flagellum. The prokaryote flagallum is a solid structures, made of the protein flagellin, which protrudes through the plasma membrane. The eukaryote flagellum (and cilium) contains a ''9 plus 2 array'', 9 microtubules in a circle with 2 microtubules in the center. Some people think that the eukaryote flagella and cilia should be called ''undulipodia''. In some species the spindles used in mitosis connect to the bases of the eukaryote cilia (undulipodia), which leads some people to think that the spindles of mitosis may have evolved from the eukaryote cilia. Some people think that the eukaryote cilium (flagellum, undulipodia) was a spirochete (prokaryote) that formed a symbiotic relationship with a eukaryote host, whose DNA was transfered to the host nucleus. Other possibilities are that the eukaryote flagellum evolved from prokaryote flagellum, or simply evolved over time through natural selection. The eukaryote flagellum protein ''tubulin'' is thought to be related to a bacterial replication/cytoskeletal protein ''FtsZ'' found in some archaebacteria (archaea). What method of reproduction this first nucleated cell used is a great mystery. Among the choices are binary division, budding, or mitosis. My own feeling is that budding or dual binary division (both nucleus and cytoplasm) was how this cell initially copied.
	291) For the first time, a cell is not constantly synthesizing DNA and then having a division period (as is the case for all known prokaryotes), but this cell has a period in between cell division and DNA synthesis where DNA synthesis is not performed. Later some cells develop a stage after synthesis and before cell division. For the first time, a cell is not constantly synthesizing DNA (S) and then having a division period (D) (as is the case for all known prokaryotes), but this cell has a period in between cell division and DNA synthesis where DNA synthesis is not performed (G1) . Later some cells develop a stage after synthesis and before cell division (G2).
2,719,000,000 YBN	302) If the first eukaryote nucleus was a prokaryote, synchronized duplication and division of organelle-nucleus and cytoplasm of early eukaryote cell evolves. Before this, eukaryote cell division usually results in one cell with no organelle-nuclei and a second cell with 2 organelle-nuclei. Perhaps the organelle-nuclei attach to the outer cell membrane in the same way the cytoplasmic DNA do, which allows new cytoplasm growth to separate the two organelle-nucleus in addition to the cytoplasmic DNA. Or perhaps the first system of organized nuclei separation originated with the organelle-nucleus flagella microtubules grewing into the cytoskeleton, and organized system spindles and mitosis. If the nuclear membrane was formed around the DNA within a prokaryote, then binary division had to adapt to separate the duplicated DNA within the proto-nucleus (not within the entire cell) which may have been very simple to evolve. If the cytoplasm grew outside the cell wall of a prokaryote, binary division would have to adapt to separate that external cytoplasm.
2,715,000,000 YBN	72) Mitosis, asexual copying of a haploid (single set of chomosomes) eukaryote nucleus, evolves in eukaryotes. Before mitosis, there is a synthesis stage where DNA in the form of chromosomes are duplicated in the nucleus before the nucleus and cell divide. explain basic process of mitosis: prophase, metaphase, anaphase, telophase Presumably no prokaryotes have ever reproduced through mitosis. Only eukaryotes reproduce asexually using mitosis. Most people accept that some protists were sexual and later lost that ability. But the majority view now is that the first eukaryotes were asexual, and that some protists still living now have never had sexual ability. Because mitosis is complex and similar in detail in all species that do mitosis, people think that mitosis only evolved once, and was inherited by all species that do mitosis. The major differences between this new method of copying, mitosis and the older method, binary fission (add budding?) are: 1) In mitosis, microtubule spindles attach to the kinetochore (the protein structure in eukaryotes which assembles on the centromere and links the chromosome to microtubule polymers from the mitotic spindle during mitosis) and pull apart the two DNA copies, where in binary fission the DNA (single chromosome) attaches to a part of the cytoplasm which pulls apart the two cells. 2) Chromosomes (linear pieces of DNA), not a circle of DNA is being copied. People speculate that early mitosis had spindles outside the nucleus, with chromosomes fastened to the nuclear membrane, as can still be seen in parabasalia and dinoflagellates, which appear to have primitive nuclei. In more ancient species the nuclear membrane persists through mitosis (closed mitosis), but in more recent species, like metazoa, land plants, and many kinds of protists, the nuclear membrane disintegrates before mitosis and is rebuilt after (open mitosis). Most people think that extranuclear spindles (spindles that originate outside of the nucleus) and closed mitosis evolved first. Only later did pleuromitosis (spindles rotate 90 degrees, nucleus can be semi-open, or closed) and then orthomitosis (spindles are on both sides of nucleus and separate chromosomes in a straight line, nucleus can be open, semi-open or closed) evolve in later eukaryotes.
2,711,000,000 YBN	303) Cytoplasmic cell fusion and division evolves. Two eukaryote cells can merge into one cell with 2 nuclei and then divide back into single 1 nucleus cells.
2,710,000,000 YBN	73) Sex (cell and genetic fusion, syngamy, gametogamy) evolves in protists. Haploid (1 set of chromosomes) eukaryote cells merge and then their nuclei merge (karyogamy) to form the first diploid (2 sets of chromosomes) cells (the first zygote). This fusion of 2 haploid cells results in the first diploid single-celled organism, which then immediately divides (both nucleus and cytoplasm by single-division meiosis) back to two haploid cells. Possibly first, only cytoplasmic merging happened with nuclear merging (karyogamy) and nuclear division (karyokinesis) evolving later. Now, two cells with different DNA can mix providing more chance of variety/mutation. Two chromosome sets provides a backup copy of important genes (sequences that code for proteins, or nucleic acids) that might be lost with only a set of single chromosomes. The life cycle of future organisms will now have two phases, a gamophase (from n to 2n [until syngamy]), and zygophase (from 2n to n [until meiosis]). Gamoid cells are not haploid in polyploid organisms. Potentially sexual cell and genetic fusion is what made the first eukaryote cell, and sex in protists may be directly descended from conjugation in prokaryotes, in other words not evolved from a different method independently of conjugation, because some metamonads, for example Saccinobaculus reproduce sexually, and look very much like a prokaryote sperm cell which formed the nucleus captured in an ovum cell. For sexual species there are 3 basic life cycles: 1) Haploid (Haplontic) life cycle: zygotic meiosis. Life as haploid cells, cell division immediately after creation of zygote from fusion. (All fungi, Some green algae, Many protozoa) 2) Diploid (Diplontic) life cycle: gametic meiosis. Instead of immediate cell division, zygote reproduces by mitosis. Haploid gametes never copy by mitosis. (animals, some brown algae) 3) Haplodiploid (Haplodiplontic, Diplohaplontic, Diplobiontic) life cycle: sporic meiosis. Diploid cell (sporocyte) meiosis results in 2 haploid sporophytes (gamonts), not 2 haploid gametes. These haploid cells then differentiate? or mitosis? to form haploid gametes. Haplodiplontic organisms have alternation of generations, one generation involves diploid spore-producing single or multicellular sporophytes (makes spores) and the other generation involves haploid single or multicellular gamete-producing multicellular gametophytes (makes gametes). Pants and many algae have this haplodiplontic life cycle. These first sexual cells are haplontic, with zygotic meiosis; they reproduce asexually through mitosis as haploid cells, fusing to a diploid cell without mitosis, then dividing back into haploid cells. An important evolutionary step evolves here in that now two cells can completely merge into one cell. This merge not only includes their nuclei, but also their cytoplasm (althought the DNA do not merge). Before now, as far as has ever been observed, no two cells have ever completely merged, although, through conjugation some prokaryotes have been observed to exchange DNA. This marks the beginning of the ''haplonic lifestyle'' with ''zygotic meosis'', where the organism is haploid until cell fusion which is immediately followed by (one-step) meiosis of the zygote, after which the haploid cells continues to reproduce through mitosis. Possibly the first sexual organism merged through a form of ''autogamy'' (both haploid gametes originate from the same individual, the opposite of ''allogamy'' where the gametes originate from different individuals). Some species reproduce by a form of autogamy (intracellular autogamy), where nuclei (also called pronuclei) divide and then merge within the same cell before the entire cell divides. Some metamonads (earliest still living eukaryotes), like Oxymonas and Saccinobaculus can reproduce asexually by mitosis, but also can reproduce sexually using this form of autogamy. This may be evidence that some prokaryote could also merge two entire cells (if the eukaryote nucleus was a prokaryote). Perhaps prokaryotes evolved full cellular fusion before the first eukaryote. If that is true, then this initial form of nuclei dividing and merging (intracellular autogamy) may have existed for some time before full eukaryote cell merging and synchronized eukayote nucleus and cytoplasm division evolved. It is difficult to see what selective advantage autogamy could possibly have since no new DNA is ever introduced into the next generation of organism, as opposed to ''allogamy'', where DNA from different individuals is merged, and which has a clear selective advantage. So perhaps autogamy evolved after allogamy, although to me it appears that allogamy is more complex than autogamy, and autogamy would be a perfect starting step to develop the needed proteins and processes for the more complicated allogamy (autogamy only involves the duplication and merging of two nuclei, where allogamy involves the merging of the cell walls, and cytoplasm in addition to the two nuclei.) This is the beginning of the label ''gamete'' for haploid cells that can merge to form a diploid zygote. In addition, the label ''gametocyte'' or ''gamont'' is any polyploid cell that divides (meiosis) into haploid gamete cells which can merge to form a zygote.
	206) Meiosis (one-step meiosis, one DNA duplication and a cell division of a diploid cell into 2 haploid cells) evolves. detail one-step meiosis: The is no DNA crossover or chiasma formation in one-division meiosis, apparently because either duplication of chromosomes or separation of chromatids does not occurred. As far as I know, mitosis and one-step meiosis are the same with the only exceptions that 1) in meiosis two haploid cells join before cell division, and 2) in mitosis the DNA is duplicated before cell division, but in meiosis the DNA is not duplicated before cell division. Meiosis can be one step (one DNA duplication and then one cell division) or two step (two DNA duplications and then two divisions). Probably one step meosis evolved first and two step meiosis later. Meiosis can only function on cells with two or more sets of chromosomes.
2,706,000,000 YBN	299) Duplication of diploid DNA (after 2 haploid cells fuse) evolves. This is required for diploid mitosis. Duplication of diploid DNA may be very similar to duplication of haploid DNA. Initially perhaps the diploid DNA duplicated, but still divided in one-division meiosis.
2,705,000,000 YBN	210) Mitosis of diploid cells evolves. This begins the ''diplontic'' life cycle (with gametic meiosis), where diploid cells (a zygote) can copy asexually through mitosis after merging. This organism, when haploid, cannot do mitosis (presumably haploid gamete mitosis will evolve much later in brown algae), and this is still true in all descendents (including humans) of this single celled organism. The proteins and mechanism of mitosis of diploid cells is probably very similar to mitosis of haploid cells. The most primitive organisms still alive that are diplontic are the metamonads (e.g. Oxymonads: Notila, Hypermastigotes: Urinympha, Macrospironympha, Rhynchonympha).
2,704,000,000 YBN	296) The origin of gender evolves: sex (cell and nucleus fusion) between two isogamous (same size) gametes but which have 2 different (+ and -) forms (genders). Perhaps the invention of two different genders originated when a flagellated cell (or nucleus) divided by binary division and only one half of the two new cells retained the flagellum. Then to differentiate the two cells even more, but still keep the same DNA template, different proteins could be weighted on one half of the cell during division to activate various operons in one gender but not the other once the two DNA pairs are separated. Perhaps sex where the gametes are the same size but cannot merge themselves should be called ''specific'' or ''gendered'' isogamy, and where any two same sized gametes can merge called ''nonspecific'' or ''nongendered'' isogamy.
2,703,000,000 YBN	297) Sex (cell and nucleus fusion) between two different size gamete cells (heterogamy or anisogamy) evolves in protists. Some species are heterogamous but two of the same sized (gender) gametes can fuse to form a zygote.
2,702,000,000 YBN	298) Sex (cell and nucleus fusion) between one flagellated gamete and an unflagellated gamete (oogamy, a form of heterogamy) evolves in protists.
2,700,000,000 YBN	62) Oldest steranes (formed from sterols, molecules made by mitochondria in eukaryotes) found in northwestern Australia.
	192) Fossils from the Bulawaya stromatolite, Zimbabwe
	214) Biomarkers characteristic of cyanobacteria, 2alpha -methylhopanes, indicate that oxygenic photosynthesis evolved well before the atmosphere became oxidizing.
2,692,000,000 YBN	300) Diploid cell fusion (Gamontogamy) evolves. Only a few species exhibit this property (e.g. the Oxymonad Notilla, Diatoms, Dasicladales [Acetabularia], in many foraminiferans, and in gregarines). Gamontogamy may have evolved into two-step meiosis. The vast majority of eukaryotes living now that reproduce sexually fuse haploid cells. All ''gametes'' are haploid cells that can merge, diploid cells that can merge are gamonts. Gamonts (Meiocytes) are cells that produce gametes. In theory this should be very similar if not exactly like haploid cell fusion, so perhaps this is not a major evolutionary step.
2,690,000,000 YBN	295) Meiosis (two step meiosis, two cell divisions with no stage in between which result in one diplid cell dividing into four haploid cells) evolves. Meiosis and mitosis are similar in being process of nucleus and cell division, but are different. Differences between meiosis and mitosis: 1) At least one crossover per homologous pair happens in 2 step meiosis but crossover usually does not happen in mitosis. 2) Two step meiosis involves cell divisions that happen one after the other, where mitosis only happens after one DNA duplication (there are never 2 mitoses together without a DNA duplication between them to my knowledge). The cell division in two step meiosis that involves a separation of sister chromatids (not homologous chromosome pairs) is basically identical to mitosis. For two step meiosis, this is the second nucleus and cell division.
2,650,000,000 YBN	170) First bacteria live on land.
2,558,000,000 YBN	171) Phylum Deinococcus-Thermus (Thermus Aquaticus [used in PCR], Deinococcus radiodurans [can survive long exposure to radiation]) evolve now. PHYLUM Deinococcus-Thermus CLASS Deinococci ORDER Deinococcales ORDER Thermales The Deinococcus-Thermus are a small group of bacteria comprised of cocci highly resistant to environmental hazards. There are two main groups. The Deinococcales include a single genus, Deinococcus, with several species that are resistant to radiation; they have become famous for their ability to eat nuclear waste and other toxic materials, survive in the vacuum of space and survive extremes of heat and cold. The Thermales include several genera resistant to heat. Thermus aquaticus was important in the development of the polymerase chain reaction where repeated cycles of heating DNA to near boiling make it advantageous to use a thermo-stable DNA polymerase enzyme. These bacteria have thick cell walls that give them gram-positive stains, but they include a second membrane and so are closer in structure to those of gram-negative bacteria.
	172) Genetic comparison shows Eubacteria phylum, Cyanobacteria (ancestor of all eukaryote chloroplasts [plastids]) evolving now. There is a conflict between the interpretation of the geological and the genetic evidence as to if oxygen photosynthesis and cyanobacteria evolved earlier around 3800mybn or here at 2500mybn. Cyanobacteria get their energy from photosythesis. Cyanobacteria include unicellular, colonial, and filamentous forms. Some filamentous cyanophytes form differentiated cells, called heterocysts, that are specialized for nitrogen fixation, and resting or spore cells called akinetes. Each individual cell typically has a thick, gelatinous cell wall, which stains gram-negative. The cyanophytes lack flagella, but may move about by gliding along surfaces. Most are found in fresh water, while others are marine, occur in damp soil, or even temporarily moistened rocks in deserts. A few are endosymbionts in lichens, plants, various protists, or sponges and provide energy for the host. Chloroplasts found in eukaryotes (algae and higher plants) most likely represent reduced endosymbiotic cyanobacteria. This endosymbiotic theory is supported by various structural and genetic similarities. Primary chloroplasts are found among the green plants, where they contain chlorophyll b, and among the red algae and glaucophytes, where they contain phycobilins. It now appears that these chloroplasts probably had a single origin. Other algae likely took their chloroplasts from these forms by secondary endosymbiosis or ingestion. tenative: CLASS Chroobacteria CLASS Hormogoneae CLASS Gloeobacteria
	315) Phylum Chloroflexi, (Green Non-Sulphur) evolve now. PHYLUM Chloroflexi CLASS Chloroflexi CLASS Thermomicrobia The Chloroflexi are a group of bacteria that produce ATP through photosynthesis. They make up the bulk of the green non-sulfur bacteria, though some are classified separately in the Phylum Thermomicrobia. They are named for their green pigment, usually found in photosynthetic bodies called chlorosomes. Chloroflexi are typically filamentous, and can move about through bacterial gliding. They are facultatively aerobic, but do not produce oxygen during photosynthesis, and have a different method of carbon fixation than other photosynthetic bacteria. Phylogenetic trees indicate that they had a separate origin.
2,500,000,000 YBN	52) End Archean Era, Start Proterozoic Era.
	56) Banded Iron Formations start to appear in many places.
2,400,000,000 YBN	59) Very large ice age that lasts 200 million years starts now.
2,335,000,000 YBN	290) The nucleolus, a sphere in the nucleus that makes ribosomes, evolves. In some eukaryotes (thought to be more ancient), the nucleolus just divides during mitosis, but in other eukaryotes the mitosis is dissolved and rebuilt after nuclear division. In euglenids, kinetoplastids, dinoflagellates, some amoebae and some coccidians, the nucleolus remains visible throughout mitosis and divides into two, but in the majority of groups the nucleolus dissapears and reforms at telophase. That the nucleolus can divide by itself suggests that it was once a free living cell.
2,330,000,000 YBN	198) Rough and smooth endoplasmic reticulum evolves in eukaryote cell. Rough and smooth endoplasmic reticulum evolves in eukaryote cell. The rough ER manufactures and transports proteins destined for membranes and secretion. It synthesizes membrane, organellar, and excreted proteins. Minutes after proteins are synthesized most of them leave to the Golgi apparatus within vesicles. The rough ER also modifies, folds, and controls the quality of proteins. The smooth ER has functions in several metabolic processes. It takes part in the synthesis of various lipids (e.g., for building membranes such as phospholipids), fatty acids and steroids (e.g., hormones), and also plays an important role in carbohydrate metabolism, detoxification of the cell (enzymes in the smooth ER detoxify chemicals), and calcium storage. It also is a large transporter of nutrient found in each cell.
2,325,000,000 YBN	199) Golgi Body (Golgi Apparatus, dictyosome) evolves in eukaryote cell. The primary function of the Golgi apparatus is to process proteins targeted to the plasma membrane, lysosomes or endosomes, and those that will be formed from the cell, and sort them within vesicles. It functions as a central delivery system for the cell. Most of the transport vesicles that leave the endoplasmic reticulum (ER), specifically rough ER, are transported to the Golgi apparatus, where they are modified, sorted, and shipped towards their final destination. The Golgi apparatus is present in most eukaryotic cells, but tends to be more prominent where there are many substances, such as proteins, being secreted. For example, plasma B cells, the antibody-secreting cells of the immune system, have prominent Golgi complexes.
2,310,000,000 YBN	200) The golgi body in eukaryote cells makes lysosomes which fuse with endosomes. The various molecules in lysosomes digest the contents of the endosome, which then exits the cell as waste.
2,305,000,000 YBN	63) A parasitic bacterium, a bacterium that can only live in other bacteria, closely related to Rickettsia prowazekii, an aerobic alpha-proteobacteria that causes louse-borne typhus, enters an early eukaryote cell. As time continues a symbiotic relationship evolves, where the Rickettsia forms the mitochondria, organelles of every euokaryote cell. The mitochondria perform the Acid Citric Cycle (Krebs Cycle), using oxygen to breakdown glucose into CO2 and H2O, and provide up 38 ATP molecules. Mitochondria reproduce by themselves, and are not created by the DNA in the cell nucleus. As time continues some of the DNA from the mitochondria merges with the cell nucleus DNA. Mitochondria produce sterol used to make the eukaryote cell wall flexible. Because mitochondria need Oxygen, but the level of oxygen is very low on earth, oxygen may be provided by photosynthesizing cyanobacteria living near these cells. All eukaryotes alive today either have mitochondria except the amitochondriate excavates (metamonads), the most ancient of the eukaryotes alive today. That parabasalids have hydrogenosomes, anaerobic organelles that seem to have evolved from mitochondria, many people think amitochondriate species lost their mitochondria over time. This changes the eukaryote cell from an anaerobic to aerobic unicellular organism. This early mitochondria may have ''tubular christae''. Perhaps there was a period of time where a system evolved to make sure both halves received mitochondria during cell division. Protists with discoidal mitochondrial cristea will later evolve from the Bikont tubular mitochondrial christae branch. For the most part: 1) Excavates, Amoebozoa, and Chromealveolates have or had tubular christae, 2) Discicristata (Euglenozoa) have discoidal christae. 3) Cryptomonads, Glaucophytes, Red Algae, Green Algae, Plants, Fungi, Animals all have flat christae. From this point on, all eukaryotes will need Oxygen to use mitochondria and receive the ATP made by mitochondria.
2,303,000,000 YBN	203) Bikonts (two cilia) evolve from Unikonts (one cilium). Bikonts (also called anterokonts for having anterior [forward facing] cilia) will evolve into the vast majority of the Protist and all of the Plant Kingdoms. The Unikonts will evolve into the ameobozoa (tenatively), and the opisthokonts (ancestrally posterior cilium) which include the entire Fungi and Animal Kingdoms.
2,300,000,000 YBN	47) Most recent evidence of uraninite, a mineral that cannot exist for much time if exposed to oxygen, indicating that free oxygen is accumulating in the air of earth for the first time.
	48) Oldest Red Beds, iron oxide formed on land, begin here and are evidence of more free oxygen in the air of earth.
	219) Genetic comparison shows the oldest line of eukaryotes still in existence, the oldest living protists, in the Phylum ''Metamonada'' (Excavates) originating now. This is where the eukaryote line is created and separates from the archaebacteria (archaea) line. Most of these species have an excavated ventral feeding groove, and all lack mitochondria. Mitochondria are thought to have been lost secondarily, although this is not certain. PHYLUM Metamonada ORDER Carpediemondida ORDER Diplomonadida ORDER Retortamonadida CLASS Parabasalia ORDER Trichomonadida ORDER Hypermastigida CLASS Anaeromonada ORDER Oxymonadida ORDER Trimastigida Includes Diplomonad ''Giardia'', and Parabasalid ''Trichomonas vaginalis''. The trophozoite form of Giardia does age and die. Most Metamonads reproduce asexually through closed (the nuclear membrane does not dissolve during mitosis) mitosis (and involves an external spindle? is pluromitosis?), but some species are ''faculatively sexual'' (can reproduce sexually in addition to asexually). So already by the time of these most ancient of the now living eukaryotes, sex had evolved. eat bacteria?
2,000,000,000 YBN	293) Genetic comparison shows the the Eukaryote Phylum ''Loukozoa'' (Jakobea and Malawimonadea) originating now. These species have mitochondria with tubular cristae, and are the most ancient species that still have mitochondria. This species is the most ancient known species to have a shell. This first hard shells (lorika) made of calcium carbonate (Calcite CaCO3), plates of silica (SiO2), or carbon-based molecules evolve around the single-celled species living in the ocean. Perhaps this shell served to protect the cell from external damage from being eaten by other eukaryotes (zooplankton), infection by bacteria or viruses, control of buoyancy, to filter UV light, against damage by non-living sources. Jakobids and Malawimonads are also grouped as Excavates because they have a ventral feeding groove. Jakobids are flagellates with two flagella located at the anterior end of a ventral feeding groove (i.e., are excavate), with mitochondria, freely swimming or loricate (with protective shell). Flagellar apparatus with two basal bodies giving rise to two major microtubular roots, which support the margins of the ventral groove. Other cytoskeletal microtubules arise directly or indirectly from the basal bodies, no extrusomes. Jakobids have tubular mitochondrial cristae (transforming to flat cristae in Jakoba libera). (1) This indicates that flat evolved from tubular cristae. PHYLUM Loukozoa ORDER Jakobida ORDER Malawimonadida
1,990,000,000 YBN	202) Eukaryotes with discoidal cristae mitochondria split from the tubular christae line. This is the origin of the Discicristata: species that have discoid mitochondrial cristae and, in some cases, a deep (excavated) ventral feeding groove. (1) The Discicristata are Acrasid slime molds, vahlkampfiid amoebas, euglenoids, trypanosomes, and leishmanias.
	301) Haplodiplontic (Diplohaplontic, Diplobiontic) life cycle (organism with both diploid and haploid ''alternate life stages'' that reproduce asexually by mitosis) with ''sporic meiosis'' evolves. In this life cycle haploid gametes fuse to form a diploid zygote which divides by meiosis producing haploid spores that produce (differentiate?) gametes, starting the cycle again. Initially these species are single celled in both stages (like Haptophyta). All plants, most brown algae, blastocladiid chytrids, many red algae, and some filamentous green algae (e.g. Cladophora) and foraminifera have haplodiploid life cycles. Initially, these organisms are single celled, but later the mitosis stages will become multicellular when the cells that result from mitosis stick together. The only? example of this is Haptophyta, where diploid cells divide in sporic meiosis, into haploid cells (gamonts) which then divide into gametes.
1,988,000,000 YBN	317) Eukaryotes that have mitochondria with flat christae evolve from those with tubular christae.
1,982,000,000 YBN	87) Genetic comparison shows the most primitive living members of the Phylum ''Euglenozoa'' (euglenids, leishmania, trypanosomes, kinetoplastids) evolved at this time. This is the oldest eukaryote to exhibit colonialism. Perhaps eukaryote colonialism is partially or fully inherited from prokaryotes, but colonialism may have evolved independently again in eukaryotes. This is the most ancient species known to have a cell covering, which is of the type ''pellicle''. No examples of sexual reproduction in the group have been found. Reproduction is through closed mitosis and involves an internal spindle. At least one account of a sexual cycle has been reported in Scytomonas. The chloroplasts are contained in three membranes and are pigmented similarly to the plants, suggesting they were retained from some captured green alga. All Euglenozoa have mitochondria with discoid cristae, which in the kinetoplastids characteristically have a DNA-containing granule or kinetoplast associated with the flagellar bases. I think they are still haploid, mitosis duplicates in nucleus? Euglenozoa age? This group is sometimes called ''Discicristates'' because all members have mitochondria with ''discoidal cristae''. Euglenids are the first eukaryotes with an eyespot. Most colored euglenids also have a stigma or eyespot, which is a small splotch of red pigment on one side of the flagellar pocket. This shades a collection of light sensitive crystals near the base of the leading flagellum, so the two together act as a sort of directional eye. Euglenozoa eyepots evolved from chloroplasts. This is the beginning of a light sensory system which evolves to eyes? A small number of euglinids have chloroplasts and can photosynthesize. In these species, the chloroplasts contain three membranes and are thought to have evolved at least 900 million years later from a captured green alga. Euglenoids, however, share reproductive habits with their kinetoplastid relations by reproducing mainly by asexual binary fission. Euglenoids reproduce very rapidly, absorbing their flagellum and dividing haploid cells through mitosis. Mitosis produces 4-8 flagellated haploid cells, called zoospores. The zoospores then break out of the parent cell and grow to full size. condensed chromosomes: yes in all kinetoplasts, and some euglenophyta. polar structures: none number of flagella: kinetoplastids=(1 in some) 2, euglenophyta=2 (4 in some) life forms: unicellular: flagellated multicellular: colonial cell covering: pellicle 2. Euglenoids are small (10-500 �m) freshwater unicellular organisms. 3. One-third of all genera have chloroplasts; those that lack chloroplasts ingest or absorb their food. 4. Their chloroplasts are surrounded by three rather than two membranes. a. Their chloroplasts resemble those of green algae. b. They are probably derived from a green algae through endosymbiosis. 5. The pyrenoid outside the chloroplast produces an unusual type of carbohydrate polymer (paramylon) not seen in green algae. 6. They possess two flagella, one of which typically is much longer and than the other and projects out of a vase-shaped invagination; it is called a tinsel flagellum because it has hairs on it. 7. Near the base of the longer flagellum is a red eyespot that shades a photoreceptor for detecting light. 8. They lack cell walls, but instead are bounded by a flexible pellicle composed of protein strips side-by-side. 9. A contractile vacuole, similar to certain protozoa, eliminates excess water. 10. Euglenoids reproduce by longitudinal cell division; sexual reproduction is not known to occur. PHYLUM Euglenozoa CLASS Euglenoidea CLASS Diplonemea CLASS Kinetoplastea CLASS Postgaardea
	294) Genetic comparison shows the Phylum ''Percolozoa'' [also called ''Heterolobosea''] (acrasid slime molds) evolved at this time. Percolozoa are a group of heterotrophic colourless protozoa, including many that can transform between amoeboid, flagellate, and encysted stages. These are collectively referred to as amoeboflagellates, schizopyrenids, or vahlkampfids. They also include the acrasids, a group of social amoebae that aggregate to form sporangia. Very closely related to Euglenozoa. All characteristics are like Euglenozoa: Percolozoa have mitochondria with discoid christae. No examples of sexual reproduction in the group have been found. Reproduction is through closed mitosis and involves an internal spindle. No chloroplasts (check) or [The chloroplasts are contained in three membranes and are pigmented similarly to the plants, suggesting they were retained from some captured green alga.] I think they are still haploid, mitosis duplicates in nucleus? Percolozoa age? Percolozoa are sometimes included in the group ''Discicristates'' because all members have mitochondria with ''discoidal cristae''. No eyespots. closed mitosis with internal spindle. The Percolozoa are the most ancient species to have members that move by pseudopodia, like amoeba. PHYLUM Percolozoa CLASS Heterolobosea ORDER Schizopyrenida Singh, 1952 ORDER Acrasida Shr�ter, 1886 (acrasids, cellular slime molds) ORDER Lyromonadida Cavalier-Smith, 1993 CLASS Percolatea ORDER Acrasida (acrasids, cellular slime molds): a. Cellular slime molds (Phylum Acrasiomycota) [t: ORDER Acrasida] exist as individual amoeboid cells. (Plasmodial slime molds, mycetozoa, which evolve later, exist as a plasmodium. ) b. They live in soil and feed on bacteria and yeast. c. As food runs out, amoeboid cells release a chemical that causes them to aggregate into a pseudoplasmodium. d. The pseudoplasmodium stage is temporary; it gives rise to sporangia that produce spores. e. Spores survive until more favorable environmental conditions return; then they germinate. f. Spore germinate to release haploid amoeboid cells, which is again the beginning of asexual cycle. g. Asexual cycle occurs under very moist conditions.
1,980,000,000 YBN	38) Multicellularity evolves in a protist. Multicellularity is a very important event in the evolution of life on earth. With multicellular organisms, larger sized organisms could evolve. There are many uncertainties surrounding the origin of multicellularity. Multicellularity may have evolved independently for Plants, Fungi and Animals, or multicellularity may have evolved only once in eukaryotes. The key feature of this cell is that a multicellular organism is made from a single cell and the multicellular organism is not a collection of independent cells (colonialism). The main difference between this organism and single-celled organisms is the way the cells stay fastened together after cell division. Which species was the first multicellular species is not clear. Multicellularity is found in all 3 life cycles (haplontic, diplontic, haplodiplontic). The 3 main life cycle types (haplontic, etc.) probably evolved in single cell species before multicellularity evolved. If multicellularity evolved once and is inherited, perhaps all multicellular organism descended from a single haplodiplontic organism. These multicellular organisms have undifferentiated cells in the multicellular stage (all cells in the haploid or diploid multicellular organism are made of one kind of cell). Dinophyta, and Fungi are multicellular Haplontic species. Most animals are multicellular Diplontic species. Most brown algae and all plants are multicellular Haplodiplontic species. The vast majority of multicellular organisms reproduce only through sex, although there are exceptions (like some plants and rotifers) which have lost the ability to sexually reproduce or can also reproduce asexually. In multicellularity, one cell goes on to produce all the cells in a multicellular species, so that each individual organism is genetically unique. This cell is usually a diploid zygote, but can be a haploid cell. This protist is most likely sexual, and multicellularity evolved only in a species that reproduces sexually. Some describe algae multicellularity as ''filamentous''. The first multicellular eukaryuotes are presumably undifferentiated. For haplontic these cells are all gametes, for diplontic these cells are all capable of meiosis to form gametes, for haplodiplontic, in the haploid stage the cells are all gamete producing, in the diploid stage the cells are all spore producing. Some people think that multicellular organisms arose at least six times: in animals, fungi and several groups of algae.
1,978,000,000 YBN	15) Multicellularity with differentiation evolves. Multicellular organisms are no longer all haploid or diploid gamete producing cells (or spore producing if haplodiplontic), but are made of gamete (or spore) producing cells in addition to somatic cells which copy asexually through mitosis. Now, in addition to being large multicell organisms, multicellular organisms can have differentiated cells that form a variety of different shaped structures, and perform different functions. This process will evolve to the metazoan multicellular differentiation that arises from a single zygote cell, where cells have different functions and shapes. Differentiation evolves for a second time in eukaryotes? this is not the first monoadmulti one cell leading to a multicellular organism (attached, free, interchangible)? where a multicellular organism is made from one cell (interchangable, specific cells: genetic specificity). It is unknown how multicellular life stages happen. For example, why one specific cell line of many produced from mitosis of a zygote will go on to do meiosis producing the haploid gamete cells which will fuse to form the next zygote, but the many other cells made from, for example, one of the two cells made after the zygote divides, will not contain the line of cells that ultimately make the gamete producing cells which continue the life cycle of the organism. Since presumably each cell in an organism contains an identical genome, perhaps a gamete producing cell can be made from any cell if specific proteins are present, or perhaps there is a protein which simply points to a certain location in the DNA which is located at a different location in the DNA for every cell, or perhaps some other explanation answers the question of how cell differentiation can happen when each cell has the same genome. A (diploid) zygote cell (the cell made by two merging gamete cells) now divides to form all cells in the differentiated multicellular organism, and is said to be ''totipotent''. Totipotent cells differentiate into ''pluripotent'' cells which can make most but not all cells in the organism. Pluripotent cells differentiate into ''multipotent'' (can make a number of cells) or ''unipotent'' cells (can only make one kind of cell).
1,974,000,000 YBN	169) For those that think algae are plants, this is where the plant kingdom begins with the evolution of brown algae (phaeophyta).
1,973,000,001 YBN	88) Genetic comparison shows the ancestor of the ''Chromalveolates'' evolving now. Chromalveolates include the Chromista and Alveolata. The Chromista include the 3 Phyla Haptophyta, Cryptophyta (Cryptomonads), and Heterokontophyta (brown algae [kelp], diatoms, water molds). Alveolata include the 3 Phyla Dinoflagellata, Apicomplexa (Malaria, Toxoplasmosis), and Ciliophora (ciliates). Chromealveolates have mitochondria with tubular cristae. Thomas Cavalier-Smith writes: ''The chromalveolate clade (Cavalier-Smith 1999) and its constituent taxa, kingdom Chromista (Cavalier-Smith 1981) and protozoan infrakingdom Alveolata (Cavalier-Smith 1991b), were all proposed based on morphological, biochemical, and evolutionary reasoning about protein targeting before there was sequence evidence for any of them. Now all are strongly supported by such evidence. Chromalveolates comprise all algae with chlorophyll c (the chromophyte algae) and all their nonphotosynthetic descendants. They arose by a single symbiogenetic event in which an early unicellular red alga was phagocytosed by a biciliate host and enslaved to provide photosynthate (Cavalier-Smith 1999, 2002c, 2003a). The strongest evidence that this occurred once only in their cenancestor is the replacement of the red algal plastid glyceraldehyde phosphate dehydrogenase (GAPDH) by a duplicate of the gene for the cytosolic version of this enzyme in all four chromalveolate groups with plastids: the alveolate sporozoa and dinoflagellates and the chromist cryptomonads and chromobiotes (Fast et al. 2001). It would be incredible for such gene duplication, retargeting by acquiring bipartite targeting sequences, and loss of the original red algal gene to have occurred convergently in four groups, but it was already pretty incredible that these groups would all have evolved a similar protein-targeting system independently and all happened to enslave a red alga, evolve chlorophyll c, and place their plastids within the rough endoplasmic reticulum (ER) independently. Yet many assumed just this because of the false dogma that symbiogenesis is easy and the failure of all these groups to cluster in rRNA trees. For chromobiotes this retargeting of GAPDH has been demonstrated only for heterokonts�information is lacking for haptophytes. However, there are five strong synapomorphies for Chromobiota, making it highly probable that the group is holophyletic (Cavalier-Smith 1994). They share the presence of the periplastid reticulum in the periplastid space instead of a nucleomorph like cryptomonads, they uniquely make the carotenoid fucoxanthin and chlorophyll c3, they uniquely have a single autofluorescent cilium, and they have tubular mitochondrial cristae with an intracristal filament. Five plastid genes now extremely robustly support the monophyly of both chromists and chromobiotes (Yoon et al. 2002). We are confident that comparable sequence evidence from nuclear genes will also eventually catch up with the general biological evidence for the holophyly of chromobiotes to convince even the most skeptical, who ignore or discount such valuable evidence that chromobiotes are holophyletic.'' Chromista include phyla: Heterokontophyta (heterokonts) (many classes) (includes colored: golden algae, axodines, diatoms, yellow-green algea, brown algae, colorless: water moulds, slime nets) Haptophyta Cryptophyta (cryptomonads) (many genera) Alveolates include the phyla: Dinoflagellata (Dinoflagellates) Apicomplexa (Apicomplexans) Ciliophora (ciliates) In 1981 Cavalier-Smith created a new kingdom called ''Chromista'' in which all chromalveolates are placed.
1,972,000,000 YBN	304) Genetic comparison shows the ancestor of Chromalveolate Phlyum Haptophyta evolving now. Some Haptophytes are haplodiploid (alternate between haploid and diploid cycles that both have mitosis), and this group is the most primitive with a haplodiploid life cycle. Haptophytes are single cellular. Haptophytes are found only in all oceans (marine) and are flagellates, almost all with plastids with chlorophylls a and c, with two flagella and one additional locomotor/feeding organelle, the haptonema. Haptophyta are a group of algae (phytoplankton). The chloroplasts are pigmented similarly to those of the heterokonts, such as golden algae, but the structure of the rest of the cell is different, so it may be that they are a separate line whose chloroplasts are derived from similar endosymbionts. The cells typically have two slightly unequal flagella, both of which are smooth, and a unique organelle called a haptonema, which is superficially similar to a flagellum but differs in the arrangement of microtubules and in its use. Haptophytes have tubular mitochondria cristae. Most haptophytes are coccolithophores, which live strictly in the oceans (marine) and are ornmmented with calcified scales called coccoliths, which are sometimes found as microfossils. Other planktonic haptophytes of note include Chrysochromulina and Prymnesium, which periodically form toxic marine algal blooms. Both molecular and morphological evidence supports their division into five orders. Emiliania is a small organism that is famous for turning huge portions of the ocean bright turquoise during its blooms. They are also known for contributing to the white cliffs of Dover because of the calcite in their coccolith cell structure. They play a very important role in the carbon cycle in the ocean because they form calcium carbonate exoskeletons that sink to the bottom of the ocean floor when they die. They are also one of the worlds major calcite producers. Sexual reproduction: Asexual, Open mitosis with spindle nucleating [originating?] in cytoplasm. Phaeocystis colonial cells diploid, motile cells haploid or diploid; reproduction by vegetative division of non-motile cells and fragmentation of colonies, vegetative division of motile cells, or by fusion of gametes. Members of the Haptophytes Genus ''Phaocystis'' form colonies [see photo]. Haptophytes are also called ''Prymnesiophytes'' Some Haptophyta have hard shell made of calcium carbonate evolves around the single-celled species living in the ocean.
1,971,000,000 YBN	305) Genetic comparison shows the ancestor of the Chromalveolate Phylum ''Cryptophyta'' (Cryptomonads) evolving now. The cryptomonads are a small group of flagellates, most of which have chloroplasts. They are common in freshwater, and also occur in marine and brackish habitats. Each cell has an anterior groove or pocket with typically two slightly unequal flagella at the edge of the pocket. Cryptomonads distinguished by the presence of characteristic extrusomes called ejectisomes, which consist of two connected spiral ribbons held under tension. If the cells are irritated either by mechanical, chemical or light stress, they discharge, propelling the cell in a zig-zag course away from the disturbance. Large ejectisomes, visible under the light microscope, are associated with the pocket; smaller ones occur elsewhere on the cell. Cryptomonads have one or two chloroplasts, except for Chilomonas which has leucoplasts and Goniomonas which lacks plastids entirely. These contain chlorophylls a and c, together with phycobilins and other pigments, and vary in color from brown to green. Each is surrounded by four membranes, and there is a reduced cell nucleus called a nucleomorph between the middle two. This indicates that the chloroplast was derived from a eukaryotic symbiont, shown by genetic studies to have been a red alga. A few cryptomonads, such as Cryptomonas, can form palmelloid stages, but readily escape the surrounding mucus to become free-living flagellates again. Cryptomonad flagella are inserted parallel to one another, and are covered by bipartite hairs called mastigonemes, formed within the endoplasmic reticulum and transported to the cell surface. Small scales may also be present on the flagella and cell body. The mitochondria have flat cristae, and mitosis is open; sexual reproduction has also been reported. Originally the cryptomonads were considered close relatives of the dinoflagellates because of their similar pigmentation. Later botanists treated them as a separate division, Cryptophyta, while zoologists treated them as the flagellate order Cryptomonadida. There is considerable evidence that cryptomonad chloroplasts are closely related to those of the heterokonts and haptophytes, and the three groups are sometimes united as the Chromista. However, the case that the organisms themselves are related is not very strong, and they may have acquired chloroplasts independently. Crytomonads often forms blooms in greater depths of lakes, or during winter beneath the ice. The cells are usually brownish in color, and have a slit-like furrow at the anterior. They are not known to produce any toxins and are used to feed small zooplankton, which is the food source for small fish in fish farming. Reproduction: Number of species: Size and shape: 10-50 μm in size and flattened in shape Mitochondria Christae: flat (which is unusual, as most chromalveolates have tubular christae). Cryotphyta may be more closely related to the Plant Kingdom and nearest Glaucophyta which also have flat christae. After one species of jakobid that changes tubular to flat christae, cryptophyta are the most ancient phylum to have flat christae.
1,970,000,000 YBN	306) Genetic comparison shows the ancestor of the Chromalveolate Phylum ''Heterokontophyta'' (Heterokonts also called Stramenopiles) evolving now. Heterokonts include brown algae, diatoms, golden algae, axodines, yellow-green algae, water moulds and slime nets. Heterkonts evolved very near the same time as the Euglinozoa did. Heterokonts all have mitochondria with tubular christae. The motile cells of heterokonts all have two unequal cilia (flagella), one ''tinsel'' (covered with hairs [mastigonemes]) cilium and one ''whiplash'' (free of hair) cilium.
1,969,000,000 YBN	307) Chromalveolate Heterokont, Brown Algae (Phaeophyta) evolves now. Brown Algae is the most genetically ancient multicellular organism still living on earth. In addition to being first to evolve multicellularity, cell differentiation (cells of different types) is already present in all brown algae. Genetic comparison shows the ancestor of the Chromalveolate Heterokont Brown Algae (Phaeophyta) evolving now. Brown Algae is the most genetically ancient multicellular organism still living on earth. In addition to being first to evolve multicellularity, cell differentiation (cells of different types) is already present in all brown algae. Brown algae belong to a large group called the heterokonts, most of which are colored flagellates. Most contain the pigment fucoxanthin, which is responsible for the distinctive greenish-brown color that gives brown algae their name. Brown algae are unique among heterokonts in developing into multicellular forms with differentiated tissues, but they reproduce by means of flagellate spores, which closely resemble other heterokont cells. Genetic studies show their closest relatives are the yellow-green algae. Most Brown algae are haplodiplontic.
1,968,000,000 YBN	308) Chromalveolate Heterokont, Diatoms evolve. Genetic comparison shows the ancestor of the Chromalveolate Heterokont Diatoms evolving now. Diatoms are diplontic. Diatoms are a very common types of phytoplankton. Most diatoms are unicellular, although some form chains or simple colonies. A characteristic feature of diatom cells is that they are encased within a unique cell wall made of silica. These walls show a wide diversity in form, some quite beautiful and ornate, but usually consist of two symmetrical sides with a split between them, hence the group name. Life Cycle When a cell divides each new cell takes as its epitheca a valve of the parent frustule, and within ten to twenty minutes builds its own hypotheca; this process may occur between one and eight times per day. Availability of dissolved silica limits the rate of vegetative reproduction, but also because this method progressively reduces the average size of the diatom frustule in a given population there is a certain threshold at which restoration of frustule size is neccesary. Auxospores are then produced, which are cells that posses a different wall structure lacking the siliceous frustule and swell to the maximum frustule size. The auxospore then forms an initial cell which forms a new frustule of maximum size within itself.
1,967,000,000 YBN	309) Chromalveolate Heterokont, Water molds (Oomycetes OemISETEZ) evolve. Genetic comparison shows the ancestor of the Chromalveolate Heterokont Water molds (Oomycetes OemISETEZ) evolving now. Oomycetes (Water molds), with about 580 species, vary from unicellular, to multicellular highly brached filamentous forms. The filamentous form is called ''coenocytic'' (grows as a large multinucleate cell that results from multiple nuclear divisions without cell divisions, also called ''mycelium'' in fungi) Oomycetes grow by closed (or nearly closed) mitosis with pairs of centrioles near the poles . Filamentous forms grow by mitosis, but only the nucleus is duplicated (karyokinesis), no septa (horizontal cell wall) is constructed, making these multinucleate very large single cells. Technically, filamentous oomycetes are 3 celled multicellular organisms because a septa forms between the vegetative filament and the diploid sporangium (and oogonium) cells (and the haploid antheridium multinucleate cells are not free swimming), but many people label oomycetes as single celled organism. But it appears clear that oomycetes would be constructed of many cells if a cell wall was built at mitosis. Sexual forms are diploid and reproduce by conjugation. Water Molds are microscopic organisms that reproduce both sexually and asexually and are composed of mycelia, or a tube-like vegetative body (all of an organism's mycelia are called its thallus). The name ''water mould'' refers to the fact that they thrive under conditions of high humidity and running surface water. Water molds were originally classified as fungi, but are now known to have developed separately and show a number of differences. Their cell walls are composed of cellulose rather than chitin and lack septa (a wall that divides two spaces) except where reproductive cells are produced, in addition to having gene sequences more closely related to brown algae than fungi. Also, in the vegetative state they have diploid nuclei, whereas fungi have haploid nuclei. The oomycetes include the water molds, white rusts and the downy mildews. Many oomycetes are multinucleate filaments (hyphae) that resemble fungi. These hyphae have no cross walls, but are one long hollow tube and are called ''coenocytic''. They were once thought to be related to the fungi, but their cell walls are made of cellulose, not chitin as they are in the true fungi. The superficial resemblance of the fungi and the oomycetes is likely a case of convergent evolution. Both groups have a filamentous (hyphal) body form with a high surface area to volume ration which facilitates uptake of nutrients from their surroundings. The oomycetes are saprobic and parasitic forms, including water molds like Saprolegnia and downey mildews like Peronospora. 1. These organisms (and slime molds) resemble fungi but all have flagellated cells which fungi never do. 2. Water molds possess a cell wall but it is made of cellulose, not chitin as in fungi. 3. Water molds produce diploid (2n) zoospores and meiosis produces the gametes. 2. Aquatic water molds parasitize fishes, forming furry growths on their gills, and decompose remains. 3. Terrestrial water molds parasitize insects and plants; a water mold caused the 1840s Irish potato famine. 4. Water molds have a filamentous body but cell walls are composed largely of cellulose. 5. During asexual reproduction, they produce diploid motile spores (2n zoospores) with flagella. 6. Unlike fungi, the adult is diploid; gametes are produced by meiosis. 7. Eggs are produced in enlarged oogonia.
1,966,000,000 YBN	310) Chromalveolate Alveolata (Ciliates, Dinoflagellates, Apicomplexans) evolve. Genetic comparison shows the ancestor of the Chromalveolate Alveolata (Ciliates, Dinoflagellates, Apicomplexans) evolving now. The alveolates are a major line of protists. There are three main groups, which are very divergent in form, but are now known to be close relatives based on various ultrastructural and genetic similarities: Ciliates Very common protozoa, with many short cilia arranged in rows Apicomplexa Parasitic protozoa that lack locomotive structures except in gametes Dinoflagellates Mostly marine flagellates, many of which have chloroplasts The most notable shared characteristic is the presence of cortical alveoli, flattened vesicles packed into a continuous layer supporting the membrane, typically forming a flexible pellicle. In dinoflagellates they often form armor plates. Alveolates have mitochondria with tubular cristae, and their flagella or cilia have a distinct structure. The Apicomplexa and dinoflagellates may be more closely related to each other than to the ciliates. Both have plastids, and most share a bundle or cone of microtubules at the top of the cell. In apicomplexans this forms part of a complex used to enter host cells, while in some colorless dinoflagellates it forms a peduncle used to ingest prey.
1,964,000,000 YBN	312) Ciliates evolve. Genetic comparison shows the ancestor of the Chromalveolate Alveolata Ciliates evolving now. The ciliates are one of the most important groups of protists, common almost everywhere there is water - lakes, ponds, oceans, and soils, with many ecto- (lives on host) and endosymbiotic (lives in host) members, as well as some obligate (depends on host for survival) and opportunistic parasites (does not depend on host for survival). Ciliates tend to be large protists, a few reaching 2 mm in length, and are some of the most complex in structure. The name ciliate comes from the presence of hair-like organelles called cilia, which are identical in structure to flagella but typically shorter and present in much larger numbers. Cilia occur in all members of the group, although the peculiar suctoria only have them for part of the life-cycle, and are variously used in swimming, crawling, attachment, feeding, and sensation. Unlike other eukaryotes, ciliates have two different sorts of nuclei: a small, diploid micronucleus (reproduction), and a large, polyploid macronucleus (general cell regulation). The latter is generated from the micronucleus by amplification of the genome and heavy editing. The high degree of polyploidi allows the cell to sustain an appropriate level of transcription. Division of the macronucleus does not occur by a mitotic process but segregation of the chromosomes is by a different process, whose mechanism is unknown. This process is not perfect, and after about 200 generations the cell shows signs of aging (has so many mutations that it does not function properly). Periodically the macronuclei is (must be?) regenerated from the micronuclei. In most, this occurs during sexual reproduction, which is not usually through syngamy but through conjugation. Here two cells line up, the micronuclei undergo meiosis, some of the haploid daughters are exchanged and then fuse to form new micro- and macronuclei. With a few exceptions, there is a distinct cytostome or mouth where ingestion takes place. Food vacuoles are formed through phagocytosis and typically follow a particular path through the cell as their contents are digested and broken down via lysosomes so the substances the vacuole contains are then small enough to diffuse through the membrane of the food vacuole into the cell. Anything left in the food vacuole by the time it reaches the cytoproct (anus) is discharged via exocytosis. Most ciliates also have one or more prominent contractile vacuoles, which collect water and expel it from the cell to maintain osmotic pressure, or in some function to maintain ionic balance. These often have a distinctive star-shape, with each point being a collecting tube. Most ciliates feed on smaller organisms (heterotrophic), such as bacteria and algae, and detritus swept into the mouth by modified oral cilia. These usually include a series of membranelles to the left of the mouth and a paroral membrane to its right, both of which arise from polykinetids, groups of many cilia together with associated structures. This varies considerably, however. Some ciliates are mouthless and feed by absorption, while others are predatory and feed on other protozoa and in particular on other ciliates. This includes the suctoria, which feed through several specialized tentacles. Ciliates and Amoeboids have in common: Food is digested in food vacuoles. Excess water is expelled by contractile vacuoles.
1,963,000,000 YBN	313) Dinoflagellates evolve. Genetic Ribosomal RNA comparison shows Chromalveolate Alveolata, Dinoflagellates evolve. Dinoflagellates reproduce mainly by haploid mitosis, but also reproduce sexually. In dinoflagellates, the chromosomes are always visible and do not condense prior to mitosis. The chromosomes are attached to the nuclear envelope, which persists during mitosis. The main method of reproduction of the dinoflagellates is by longitudinal cell division, with each daughter cell receiving one of the flagella ad a portion of the theca and then constructing the missing parts in a very intricate sequence. Some nonmotile species form zoospores, which may be colonial. A number of species reproduce sexually, mostly by isogamy, but a few species reproduce by heterogamy (anisogamy). Dinoflagellate zygotes are similar to some acritarchs (early eukaryote fossils). Some Dinoflagellates produce cysts. The dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well; their populations are distributed depending on temperate, saltiness, or depth. About half of all dinoflagellates are photosynthetic, and these make up the largest group of eukaryotic algae aside from the diatoms. Being primary producers make them an important part of the food chain. Some species, called zooxanthellae, are endosymbionts of marine animals and protozoa, and play an important part in the biology of coral reefs. Other dinoflagellates are colorless predators on other protozoa, and a few forms are parasitic. Some dinoflagellates are reported to be filamentous (multicellular). Mitochondria christae are tubular. Dinoflagellates are haploid (haplontic).
1,962,000,000 YBN	314) Apicomplexans evolve. Genetic comparison shows Apicomplexans evolve. The Apicomplexa are a large group of protozoa, characterized by the presence of an apical complex at some point in their life-cycle. They are exclusively parasitic, and completely lack flagella or pseudopods except for certain gamete stages. Diseases caused by Apicomplexa include: * Babesiosis (Babesia) * Cryptosporidiosis (Cryptosporidium) * Malaria (Plasmodium) * Toxoplasmosis (Toxoplasma gondii) Most members have a complex life-cycle, involving both asexual and sexual reproduction. Typically, a host is infected by ingesting cysts, which divide to produce sporozoites that enter its cells. Eventually, the cells burst, releasing merozoites which infect new cells. This may occur several times, until gamonts are produced, forming gametes that fuse to create new cysts. There are many variations on this basic pattern, however, and many Apicomplexa have more than one host.
1,961,000,000 YBN	89) Genetic comparison shows Rhizaria (the Phyla ''Radiolaria'', ''Cercozoa'', and ''Foraminifera'') evolve now. This marks the beginning of the protists described as ''amoeboid'', because they have pseudopods. 5. Amoeboids phagocytize their food; pseudopods surround and engulf prey. 6. Food is digested inside food vacuoles. 7. Freshwater amoeboids have contractile vacuoles to eliminate excess water. Some foraminifera are haplodiploid (alternate between haploid and diploid cycles that both have mitosis). The Rhizaria are a major line of protists. They vary considerably in form, but for the most part they are amoeboids with filose, reticulose, or microtubule-supported pseudopods. Many produce shells or skeletons, which may be quite complex in structure, and these make up the vast majority of protozoan fossils. Nearly all have mitochondria with tubular cristae. There are three main groups of Rhizaria: Cercozoa Various amoebae and flagellates, usually with filose pseudopods and common in soil Foraminifera Amoeboids with reticulose pseudopods, common as marine benthos Radiolaria Amoeboids with axopods, common as marine plankton The name Rhizaria was created recently by Cavalier-Smith in 2002. Most are biciliate amoeboflagellates at some point in the life cycle. Pseudopodia are root-like reticulopodia, filopodia and/or axopodia � not broad lobopodia as in Amoeba. All of these features can, however, be found in members of other clades. Nevertheless, the Rhizaria are supported by both rRNA and actin trees (Cavalier-Smith & Chao, 2003; Nikolaev et al. 2004).
	320) Rhizaria Phylum ''Cercozoa'' evolve now. The Cercozoa are a group of protists, including most amoeboids and flagellates that feed by means of filose pseudopods. These may be restricted to part of the cell surface, but there is never a true cytostome or mouth as found in many other protozoa. They show a variety of forms and have proven difficult to define in terms of structural characteristics, although their unity is strongly supported by genetic studies.
1,960,000,000 YBN	319) Rhizaria Phylum ''Radiolaria'' evolve now. Ribosomal RNA indicates that Rhizaria Phylum ''Radiolaria'' evolve now. Radiolarians (also radiolaria) are amoeboid protozoa that produce intricate mineral skeletons, typically with a central capsule dividing the cell into inner and outer portions, called endoplasm and ectoplasm. They are found as plankton throughout the ocean, and their shells are important fossils found from the Cambrian onwards. Move by pseudopodia. external tests made of silica (glass). Radiolaria have a test composed of silica or strontium sulfate. Most have a radial arrangement of spines. Pseudopods (actinopods) project from an external layer of cytoplasm and are supported by rows of microtubules. Tests of dead foraminiferans and radiolarians form deep layers of ocean floor sediment. Back to the Precambrian, each layer has distinctive foraminiferans which helps date rocks. Over hundreds of millions of years, the CaCO3 shells have contributed to the formation of chalk deposits (i.e. White Cliffs of Dover, limestone of pyramids). Lifecycle Simple asexual fission of radiolarian cells has been observed. Sexual reproduction has not been confirmed but is assumed to occur; possible gametogenesis has been observed in the form of ''swarmers'' being expelled from swellings in the cell. Swarmers are formed from the central capsule after the ectoplasm has been discarded. The central capsule sinks through the water column to depths hundreds of meters greater than the normal habitat and swells, eventually rupturing and releasing the flagellated cells. Recombination of these cells, which are assumed to be haploid, to produce diploid ''adults'' has not been observed however and is only inferred to occur. Comparisons of standing crops within the water column and sediment trap samples have ascertained that the average life span of radiolarians is about two weeks, ranging from a few days to a few weeks.
	321) Rhizaria Phylum ''Foraminifera'' evolve now. Ribosomal RNA shows Rhizaria Phylum ''Foraminifera'' (also known as ''Granuloreticulosea'') evolve now. Forminifera are catagorized as amoeboid because they have pseudopods. The Foraminifera, or forams for short, are a large group of amoeboid protists with reticulating pseudopods, fine strands that branch and merge to form a dynamic net. They typically produce a shell, or test, which can have either one or multiple chambers, some becoming quite elaborate in structure. About 250 000 species are recognized, both living and fossil. They are usually less than 1 mm in size, but some are much larger, and the largest recorded specimen reached 19 cm. As fossils, foraminifera are extremely useful. Foraminifera are haplodiploid. Most have a kind of shell called a ''test'', which is composed of calcium carbonate. move by pseudopodia most are marine tests are major components of limestone used to date marine sediments. Foraminifera, especially the calcareous forms, have a fossil record stretching back to the Cambrian (Lee, 1990), and are especially important biostratigraphically. b. Foraminiferans have a multi-chambered CaCO3 (calcium carbonate) shell; thin pseudopods extend through holes. Of the approximately 4000 living species of foraminifera the life cycles of only 20 or so are known. There are a great variety of reproductive, growth and feeding strategies, however the alternation of sexual and asexual generations is common throughout the group and this feature differentiates the foraminifera from other members of the Granuloreticulosea. An asexually produced haploid generation commonly form a large proloculus (initial chamber) and are therefore termed megalospheric. Sexually produced diploid generations tend to produce a smaller proloculus and are therefore termed microspheric. Importantly in terms of the fossil record, many foraminiferal tests are either partially dissolved or partially disintegrate during the reproductive process.The planktonic foraminifera Hastigerina pelagica reproduces by gametogenesis at depth, the spines, septa and apertural region are resorbed leaving a tell-tale test. Globigerinoides sacculiferproduces a sac-like final chamber and additional calcification of later chambers before dissolution of spines occurs, this again produces a distinctive test, which once gametogenesis is complete sinks to the sea bed. Since the meiosis products have to differentiate or mature into gametes, meiosis does not result directly in gametes, these species are haplodipoid (haplodiplontic).
1,900,000,000 YBN	66) Oldest Acritarch (eucaryote) fossils. These fossils are reported to be both in Chuanlinggou Formation, China and in Russia. Acritarchs, the name coined by Evitt in 1963 which means ''of uncertain origin'', are an artificial group. The group includes any small (most are between 20-150 microns across), organic-walled microfossil which cannot be assigned to a natural group. They are characterised by varied sculpture, some being spiny and others smooth. They are believed to have algal affinities, probably the cysts of planktonic eukaryotic algae. They are valuable Proterozoic and Palaeozoic biostratigraphic and palaeoenvironmental tools.
1,874,000,000 YBN	61) Oldest non-acritarch Eukaryote fossil Grypania spiralis (an alga 10 cm long) from BIF in Michigan. Oldest algae fossil. The date of this fossil was originally 2100mybn, but Schneider measured the Marquette Range Supergroup (MRS), A rhyolite in the Hemlock Formation, a mostly bimodal submarine volcanic deposit that is laterally correlative with the Negaunee Iron-formation, yields a sensitive high-resolution ion microprobe (SHRIMP) U�Pb zircon age of 1874 � 9 Ma. In 1992, Han and Runnegar, finders of this fossil, compared the fossil to Acetabularia, a single-celled green algae. If true, this would make Grypania the oldest green algae fossil.
1,800,000,000 YBN	46) End of the Banded Iron Formation Rocks.
1,576,000,000 YBN	67) A eukaroyte cell forms a symbiotic relationship with cyanobacteria, which form plastids (chloroplasts). Like mitochondria, these organelles copy themselves and are not made by the cell DNA. Depending on their morphology and function, plastids are commonly classified as chloroplasts, leucoplasts, amyloplasts or chromoplasts.
1,513,000,000 YBN	221) First fungi evolve. Genetic comparison shows fungi evolving now. This begins the fungi kingdom. Perhaps fungi evolved from the amoebozoa slime mold line, because the sporangiophore (stalk) and sporangium (ball on top) of slime molds look very similar to many fungi.
1,500,000,000 YBN	323) First plant (single cell, similar to glaucophytes) evolves. Ribosomal RNA place first plant (single cell, similar to glaucophytes) evolving here. This begins the plant kingdom. Cavelier-Smith and Ema E. -Y. Chao write: ''Kingdom Plantae (sensuCavalier-Smith 1981) was originally defined as comprising all eukaryotes with chloroplasts possessing an envelope of two membranes and mitochondria with (irregularly) flat cristae. It originally included Viridaeplantae (green algae and embryophyte or �higher� plants), Rhodophyta (red algae), and Glaucophyta (e.g., Cyanophora, Glaucocystis). It was argued that all three groups diverged from a single primary symbiogenetic origin of plastids (Cavalier-Smith 1982). Both the monophyly of plastids and that of Glaucophyta and Plantae long met unreasonably strong opposition because of widespread false dogma that symbiogenesis is easy and because the three taxa usually do not group together in 18S rRNA trees. Now, however, derived features of all plastids compared with cyanobacteria and numerous molecular trees have led to the acceptance of plastid monophyly (Delwiche and Palmer 1998) and to the monophyly of glaucophyte algae. Furthermore, a sister relation between red algae and Viridaeplantae is strongly supported by concatenated protein trees for nuclei (Moreira et al. 2000; Baldauf et al. 2000) and chloroplasts (Martin et al. 1998; Turmel et al. 1999). The sister relationship between them and glaucophytes is convincingly, but significantly more weakly, supported by the same trees. Thus the case of Plantae shows that arguments from morphology and evolutionary considerations of protein targeting during symbiogenesis (Cavalier-Smith 2000b) gave the correct answer much more rapidly than single-gene trees, which still do not clearly group all three taxa together. In all our trees in the present study (and the recent tree of Edgcomb et al. 2002), Rhodophyta and Viridaeplantae are sisters, but with weak support. Glaucophyta wander aimlessly from one place to another in different trees.''
1,492,000,000 YBN	173) Roper Group eukaryote algea microfossils.
1,400,000,000 YBN	86) Glaucophyta evolve. Genetic comparison shows Phylum Glaucophyta evolving at this time. Some people catagorize Glaucophyta in the kingdom Plantae instead of Protista, and label glaucophyta the most ancient living plants. The glaucophytes, also referred to as glaucocystophytes or glaucocystids, are a tiny group of freshwater algae. They are distinguished mainly by the presence of cyanelles, primitive chloroplasts which closely resemble cyanobacteria and retain a thin peptidoglycan wall between their two membranes. It is thought that the green algae (from which the higher plants evolved), red algae and glaucophytes acquired their chloroplasts from endosymbiotic cyanobacteria. The other types of algae received their chloroplasts through secondary endosymbiosis, by engulfing one of those types of algae along with their chloroplasts. The glaucophytes are of obvious interest to biologists studying the development of chloroplasts: if the hypothesis that primary chloroplasts had a single origin is correct, glaucophytes are closely related to both green plants and red algae, and may be similar to the original alga type from which all of these developed. Glaucophytes have mitochondria with flat cristae, and undergo open mitosis without centrioles. Motile forms have two unequal flagella, which may have fine hairs and are anchored by a multilayered system of microtubules, both of which are similar to forms found in some green algae.
	197) Opisthokonts (posterior cilium) evolve from Unikonts (ancestrally only one cilium). Opisthokonts have flat mitochondrial cristae and go on to form the Animal and Fungi kingdoms. Thomas Cavalier-Smith and Ema E.-Y. Chao write: ''The term opisthokont, signifying �posterior cilium,� was applied to animals, Choanozoa, and Fungi because all three groups ancestrally had a single posterior cilium (Cavalier-Smith 1987b). They were argued to be a clade because they also were characterized (uniquely at the time) by flat, nondiscoid mitochondrial cristae that were not irregularly inflated like the flat cristae of Plantae (Cavalier-Smith 1987b). Four other characters also suggested that animals and fungi were more closely related to each other than plants (chitinous exoskeletons; storage of glycogen, not starch; absence of chloroplasts; and UGA coding for tryptophane, not chain termination). However, the first three were probably ancestral states for eukaryotes and the last convergent, so the ciliary and cristal morphology were stronger indications. Although early rRNA trees did not group animals and fungi together, the opisthokonts are now consistently supported by all well-sampled rRNA trees and trees using several or many proteins, as discussed above. Moreover a derived 12-amino acid insertion in translation elongation factor 1agr and three small gaps in enolase clearly indicate that animals and fungi have a common ancestor not shared with plants (or other bikonts) or Amoebozoa (Baldauf and Palmer 1993; Baldauf 1999). Thus opisthokonts are now well accepted as a robust clade of eukaryotes (Patterson 1999).''
	220) Amoebozoa (amoeba, slime molds) evolve now. Ribosomal RNA shows the Protist Phylum Amoebozoa (also called Ramicristates) which includes amoeba and slime molds evolving now. The Amoebozoa are a major group of amoeboid protozoa, including the majority that move by means of internal cytoplasmic flow. Their pseudopodia are characteristically blunt and finger-like, called lobopodia. Most are unicellular, and are common in soils and aquatic habitats, with some found as symbiotes of other organisms, including several pathogens. The Amoebozoa also include the slime moulds, multinucleate or multicellular forms that produce spores and are usually visible to the unaided eye. Mycetozoa are the slime molds. 4. Plasmodial Slime Molds a. Plasmodial slime molds exist as a plasmodium. (the earlier evolved acrasid cellular slime molds exist as individual amoeboid cells.) b. This diploid multinucleated cytoplasmic mass creeps along, phagocytizing decaying plant material. c. Fan-shaped plasmodium contains tubules of concentrated cytoplasm in which liquefied cytoplasm streams. d. Under unfavorable environmental conditions (e.g., drought), the plasmodium develops many sporangia that produce spores by meiosis. e. When mature, spores are released and survive until more favorable environmental conditions return; then each releases a haploid flagellated cell or an amoeboid cell. f. Two flagellated or amoeboid cells fuse to form diploid zygote that produces a multi-nucleated plasmodium. Nuclear division in giant amoebas (Peolobiont/Amoebozoa) is neither mitosis nor binary fission, but incorporates aspects of both (Fig. 3-7). Chromosomes are attached permanently to the nuclear membrane by their centromeres (MTOCs, microtubule organizing centers), and the nuclear membrane remains intact throughout division. After DNA duplication produces two chromatids, the point of attachment, the MTOC duplicates or divides, and microtubules are assembled between the two resulting MTOCs. Elongating microtubules form something akin to a spindle within the nuclear membrane that pushes the daughter chromosomes apart and elongate the membrane-bounded nucleus until it blebs in half in something akin to binary fission. Simple assembly of microtubules accomplishes the separation of daughter genomes in this simple nuclear division. In typical eukaryotic mitosis, the separation of daughter chromosomes is accomplished by a dual action, the disassembly of spindle fibers connecting the daughter chromosome to the polar MTOC, and assembly of spindle fibers running pole to pole. amoeba haplodiploid?
1,300,000,000 YBN	188) Green Algae, composed of the 2 Phlya Chlorophyta (volvox, sea lettuce) and Charophyta (Spirogyra) evolve. Genetic comparison shows Green Algae, composed of the 2 Phlya Chlorophyta (volvox, sea lettuce) and Charophyta (Spirogyra) evolving now. The Green Algae are the large group of algae from which the embryophytes (higher plants) emerged. As such they form a paraphyletic group, some people placing them in the Plantae Kingdom, while others placing them in the Protist Kingdom. Almost all forms have chloroplasts. They are bound by a double membrane, so presumably were acquired by direct endosymbiosis of cyanobacteria. All green algae have mitochondria with flat cristae. When present flagella are typically anchored by a cross-shaped system of microtubules, but these are absent among the higher plants and charophytes. They usually have cell walls containing cellulose, and undergo open mitosis without centrioles. Sexual reproduction varies from fusion of identical cells (isogamy) to fertilization of a large non-motile cell by a smaller motile one (oogamy). However, these traits show some variation, most notably among the basal green algae, called prasinophytes. The first land plants most likely evolved from green algae. Here is where the green algae separate from the ancestor of the first land plants. Spirogyra reproduce through conjugation, which either was inherited from prokaryotes or evolved a second time in eukaryotes. Some filamentous green algae (e.g. cladophora) are haplodiploid (alternate between haploid and diploid cycles that both have mitosis).
	209) Red Algae (Rhodophyta) evolve now. Genetic comparison show Phylum Rhodophyta (red algae) evolves now. There are between 2500 and 6000 species in about 670 largely marine genera. Many red algae are haplodiploid (alternate between haploid and diploid cycles that both have mitosis). The red algae (Rhodophyta) are a large group of mostly multicellular, marine algae, including many notable seaweeds. Most of the coralline algae, which secrete calcium carbonate and play a major role in building coral reefs, belong here. Red algae such as dulse and nori are a traditional part of European and Asian cuisine and are used to make certain other products like agar and food additives. Many red algae have multicellular stages but these lack differentiated tissues and organs. Unlike most other algae, no cells with a flagellum are found in any member of the group. Unicellular forms typically live attached to surfaces rather than floating among the plankton, and both the larger female and smaller male gametes are non-motile, so that most have a low chance of fertilization. They have cell walls are made out of cellulose and thick gelatinous polysaccharides, which are the basis for most of the industrial products made from red algae. The chloroplasts of red algae are bound by a double membrane, like those of green plants; both groups (Archaeplastida) probably share a common origin. Their plastids formed by direct endosymbiosis of a cyanobacteria, and in red algae are pigmented with chlorophyll a and various proteins called phycobilins, which are responsible for their reddish color. Other algae that lack chlorophyll b appear to have acquired their chloroplasts from red algae, although their pigmentations are somewhat different. unicellular to multicellular (up to 1 m) mostly free-living but some parasitic or symbiotic, with chloroplasts containing phycobilins. Cell walls made of cellulose with mucopolysaccharides penetrated in many red algae by pores partially blocked by proteins (complex referred to as pit connections). Usually with separated phases of vegetative growth and sexual reproduction. Common and widespread, ecologically important, economically important (source of agar). No flagella. Ultrastructural identity: Mitochondria with flat cristae, sometimes associated with forming faces of dictyosomes. Thylakoids single, with phycobilisomes, plastids with peripheral thylakoid. During mitosis, nuclear envelope mostly remains intact but some microtubules of spindle extend from noncentriolar polar bodies through polar gaps in the nuclear envelope. Synapomorphy: No clear-cut feature available; possibly pit connections Composition: About 4,000 species. CLASS Florideophyceae CLASS Bangiophyceae CLASS Rhodellophyceae
1,280,000,000 YBN	187) A eukaryote rhodophyte (red alga) is enslaved by a chromealveolate eukaryote to form a plastid in the chromealveolate. This kind of plastid is presumably inherited by all other chromalveolates (brown algae, diatoms, water molds, Dinoflagellata, Apicomplexa, ciliates) that have plastids. If this red alga endosymbiosis occured only once, then all chromalveolates with plastids inherited them and all without lost them. Ciliates presumably lost any inherited plastids.
1,250,000,000 YBN	201) Oldest widely accepted Rhodophyta (red algae) fossils (Bangiomorpha pubescens) from Hunting Formation, Somerset Island, arctic Canada. This is the oldest multicellular eukaryote fossil and the oldest fossil of a sexual species found yet.
1,100,000,000 YBN	75) Most ancient living fungi phylum ''Microsporidia'' evolves. Ribosomal RNA shows most ancient living fungi phylum ''Microsporidia'' evolving now. Microsporidia are parasites of animals, now considered to be extremely reduced fungi. Most infect insects, but they are also responsible for common diseases of crustaceans and fish, and have been found in most other animal groups, including humans and other mammals which can be parasitized by species of Encephalitozoon. Replication takes place within the host's cells, which are infected by means of unicellular spores. These vary from 1-40 μm, making them some of the smallest eukaryotes. They also have the shortest eukaryotic genomes. Microsporidia are unusual in lacking mitochondria, and also lack motile structures such as flagella. The spores are protected by a layered wall including proteins and chitin. Their interior is dominated by a unique coiled structure called a polar tube (not to be confused with the polar filaments of Myxozoa). In most cases there are two closely associated nuclei, forming a diplokaryon, but sometimes there is only one. Intracellular parasites, no mitochondria, ribosomes are unusual in being of prokaryotic size (70S) and lacking characteristic eukaryotic 5.8S ribosomal RNA as a separate molecule in the microsporidia but is incorporated into the 23S r RNA. binucleate haploid?
1,000,000,000 YBN	223) Fungi phylum ''Chytridiomycota'' evolves. Ribosomal RNA place fungi phylum ''Chytridiomycota'' evolving now. Many chytrids are haplodiploid (alternate between haploid and diploid cycles that both have mitosis). Chytridiomycota is a division of the Fungi kingdom and contains only one class, Chytridiomycetes. The name refers to the chytridium (from the Greek, chytridion, meaning ''little pot''): the structure containing unreleased spores. The chytrids are the most primitive of the fungi and are mostly saprobic (feed on dead species, degrading chitin and keratin). Many chytrids are aquatic (mostly found in freshwater). There are approximately 1,000 chytrid species, in 127 genera, distributed among 5 orders. Both zoospores and gametes of the chytrids are mobile by their flagella, one whiplash per individual. The thalli are coenocytic and usually form no true mycelium (having rhizoids instead). Some species are unicellular.
	324) Phylum Choanozoa (Mesomycetozoea/DRIPs, Choanoflagellates) evolves.
	325) The Choanozoan ''Mesomycetozoaea'' (DRIPs) evolve. The Mesomycetozoea or DRIP clade are a small group of protists, mostly parasites of fish and other animals. One species, Rhinosporidium seeberi, infects birds and mammals, including humans. They are not particularly distinctive morphologically, appearing in host tissues as enlarged spheres or ovals containing spores, and most were originally classified in various groups of fungi, protozoa, and algae. However, they form a coherent group on molecular trees, closely related to both animals and fungi and so of interest to biologists studying their origins. The name DRIP is an acronym for the first protozoa identified as members of the group - Dermocystidium, the rosette agent, Ichthyophonus, and Psorospermium. Cavalier-Smith later treated them as the class Ichthyosporea, since they were all parasites of fish. Since other new members have been added, Mendoza et al. suggested changing the name to Mesomycetozoea, which refers to their evolutionary position. Note the name Mesomycetozoa (without a second e) is also used to refer to this group, but Mendoza et al. use it as an alternate name for the phylum Choanozoa. Assemblage identified from molecular studies, mostly pathogens, a few genera, no synapomorphy. Grouping formalized by Herr, Ajello, Taylor, Arseculeratne & Mendoza, 1999.
	585) The Neoproterozoic (1.0-0.65Ga) is a period of dramatic global change and quickening reef evolution. The appearance of heavily calcified microbial elements (calcimicrobes; e.g. Girvanella and Renalcis) in the Tonian (1.0-0.85Ga), coincident with the disappearance of conical elements and decline in stromatolites, is a critical event.
967,000,000 YBN	97) A lens and light sensitive area evolve in unicellular eukaryote living objects. This is the first proto eye. The eye spot probably evolved from a plastid, and plastids may have only formed symbiotic relationships in euglenozoa much later, since the plastids in euglenozoa are enclosed in 3 membranes (the same as chloroplasts in plants), they are thought to have been formed from captured green algae which evolve much later.
900,000,000 YBN	326) The Choanozoans ''Choanoflagellates'' and ''Acanthoecida'' evolve. The choanoflagellates are a group of flagellate protozoa. They are considered to be the closest relatives of the animals, and in particular may be the direct ancestors of sponges. Each choanoflagellate has a single flagellum, surrounded by a ring of hairlike protrusions called microvilli, forming a cylindrical or conical collar (choanos in Greek). The flagellum pulls water through the collar, and small food particles are captured by the microvilli and ingested. It also pushes free-swimming cells along, as in animal sperm, whereas most other flagellates are pulled by their flagella. Most choanoflagellates are sessile, with a stalk opposite the flagellum. A number of species are colonial, usually taking the form of a cluster of cells on a single stalk. Of special note is Proterospongia, which takes the form of a glob of cells, of which the external cells are typical flagellates with collars, but the internal cells are non-motile. The choanocytes (also known as ''collared cells'') of sponges have the same basic structure as choanoflagellates. Collared cells are occasionally found in a few other animal groups, such as flatworms. These relationships make colonial choanoflagellates a plausible candidate as the ancestors of the animal kingdom.
855,000,000 YBN	286) A key step in metazoan multicellularity evolves, where a zygote produces differentiated cells that stick together to form one organism. Metazoan multicellularity appears to be different from colonialism (where independent cells of the same species work together and function as one unit), because one zygote produces all the cells in the organism.
850,000,000 YBN	81) First animal and first metazoan evolve. Metazoans are multicellular, but their cells perform different functions and originate from one cell(?). This is`also the beginning of the Animal Subkingdom ''Radiata'', species with radial symmetry. These are the sponges. There are only 3 kinds of metazoans: sponges, cnidarians, and bilaterians (which include all insects and vertibrates). Sponges are the first organisms whose DNA codes for more than one kind of cell. Sponges have 3 different cell types. Some cells form a body wall, some digest food, some form a skeletal frame. All sponge cells are totipotent and are capable of regrowing a new sponge. The two major subkingdoms of the Kingdom Animalia are Radiata (the radiates) and Bilateria (the bilaterians).
	101) First homeobox, or ''hox'' genes evolve. These genes regulate the building of major body parts.
	224) Genetic comparison shows Fungi division ''Zygomycota'' (bread molds, pin molds, microsporidia,...) evolving now. Mucorales/Blastocladiales
780,000,000 YBN	79) Animal Phylum ''Placozoa'' evolves. Placozoans look like amoebas but are multicellular. There is only one known species, ''Tricoplax adhaerens'', and one other potential species ''Tricoplax reptans'' in the entire Placozoa phylum. Putative eggs have been observed, but they degrade at the 32-64 cell stage. Neither embryonic development nor sperm have been observed, however Trichoplax genomes show evidence of sexual reproduction. Asexual reproduction by binary fission is the primary mode of reproduction observed in the lab. The haploid number of chromosomes is six. It has the smallest amount of DNA yet measured for any animal with only 50 megabases (80 femtograms per cell). A trichoplax genome project is currently underway.
750,000,000 YBN	83) Animal Phlyum Ctenophora (comb jellies) evolves.
	225) Genetic comparison shows Fungi division ''Glomeromycota'' (Arbuscular mycorrhizal fungi) evolving now.
700,000,000 YBN	82) First cnidarians (coelantrates), jellyfish evolves. Jellyfish have photon detecting cells and a lens made of ?.
	226) The second largest group of Fungi, the phylum ''Basidiomycota'' (most mushrooms, rusts, club fungi) evolve. Genetic comparison shows the second largest group of Fungi, the phylum ''Basidiomycota'' (most mushrooms, rusts, club fungi) evolving now. The Division Basidiomycota is a large taxon within the Kingdom Fungi that includes those species that produce spores in a club-shaped structure called a basidium. Essentially the sibling group of the Ascomycota, it contains some 30,000 species (37% of the described fungi)
	227) The largest Fungi phylum ''Ascomycota'' (yeasts, truffles, Penicillium, morels, sac fungi) evolves. Genetic comparison shows the largest Fungi phylum ''Ascomycota'' (yeasts, truffles, Penicillium, morels, sac fungi) evolving now. 47,000 described species.
	228) Genetic comparison shows the largest and second largest lines of Fungi (Ascomycota and Basidiomycota) splitting now.
680,000,000 YBN	222) Genetic comparison shows the Class of Ascomycota Fungi called ''Archaeascomycetes'' (fission yeast, pneumonia fungus) evolving now.
650,000,000 YBN	69) Start of Varanger Ice Age (650-590 mybn).
	229) Genetic comparison shows the Ascomycota Fungi ''Hemiascomycetes'' evolving now.
630,000,000 YBN	91) First bilateral (has 2 sided symmetry) species evolves. Animal phylum Acoelomorpha (acoela flat worms and nemertodermatida) evolves. This begins the Subkingdom ''Bilateria''. lack a digestive track, anus and coelom.
600,000,000 YBN	231) Basidiomycota Fungi ''Ustilaginomycetes'' (corn smut fungus) and ''Hymenomycetes'' (white rot fungus) evolve.
590,000,000 YBN	70) End of Varanger Ice Age (650-590 mybn).
	93) Protostomes evolve. Many phyla evolve at this time. Protostomes include the 3 infrakingdoms Ecdysozoa (a variety of worms and the arthropods [a huge group including all insects and crustaceans]), Platyzoa (rotifers and flatworms), and Lophotrochozoa (brachiopods [clams], molluscs [snails], and a variety of worms).
580,000,000 YBN	94) Earliest animal fossil from Doushantuo formation in China.
	165) Earliest bilaterian fossil, Vernanimalcula, 178 um in length, from Doushantuo Formation, China. First fossil of organism with bilateral symmetry, mouth, digestive track, gut and anus.
	318) Protostome Infrakingdom Ecdysozoa evolves. Ecdysozoa are animals that molt (lose their outer skins) as they grow. Ecdysozoa include: the Phylum ''Chaetognatha'' (Arrow Worms), the Superphylum ''Aschelminthes'', containing the 5 Phlya: ''Kinorhyncha'' (kinorhynchs) ''Loricifera'' (loriciferans) ''Nematoda'' (round worms) ''Nematomorpha'' (horsehair worms), ''Priapulida'' (priapulids) the Superphlyum ''Panarthropoda'' containing the 3 Phyla: ''Arthropoda'' (arthropods: insects, shell fish) ''Onychophora'' (onychophorans) ''Tardigrada'' (tardigrades)
575,000,000 YBN	107) Start of fossils in Ediacaran fauna near Adelaide, Australia.
574,000,000 YBN	96) First neuron, nerve cell, and nervous system evolves in bilaterians.
570,000,000 YBN	95) Fluid filled cavity, coelom evolves in early bilaterians.
	105) Deuterostomes evolve. This is the beginning of the Subkingdom Deuterostomia and Infrakingdom ''Coelomopora'' (Ambulacraria) with the two Phyla ''Hemichordata'' (acorn worms) and ''Echinodermata'' (sea cucumbers, sea urchins, starfish).
	311) Ecdysozoa phylum Chaetognatha (Arrow Worms) evolves.
	345) Deuterostome Coelomorpha Phylum Hemichordonia (acorn worms) evolves.
	346) Deuterostome Coelomorpha Phylum Echinodermata (sea cucumbers, sea urchins, sand dollars, star fish) evolves.
565,000,000 YBN	98) First circulatory system and red blood cells evolve in bilaterian worms.
	327) Infrakingdom Platyzoa (includes Superphylum Gnathifera [gnathiferans], Phylum Gastrotricha [gastrotrichs], and Phylum Platyhelminthes [flatworms]) evolve.
	347) Deuterostome Phylum Chordata evolves. Chordata is a very large group that contains all fish, amphibians, reptiles and mammals.
	348) Deuterstome Chordata Subphylum Tunicata (tunicates [sea squirts]) evolves.
562,000,000 YBN	99) Segmentation evolves.
561,000,000 YBN	100) Filter feeding, filtering food and oxygen from water through a digestive system, evolves in segmented worms.
560,000,000 YBN	117) Oldest fossil of chordate, Ediacaran fossil.
	330) The two Ecdysozoa Superphyla Ashelminthes (round worms, horsehair worms, priapulids) and Pananthropoda (arthropods, onychophorans, tardigrades) separate.
	349) Deuterstome Chordata Subphylum Cephalochordata (lancelets) evolves. This is the first fish.
550,000,000 YBN	328) Ecdysozoa Superphylum ''Ashelminthes'' evolves. This includes the 5 Phyla: Kinorhyncha (kinorhynchs), Loricifera (loriciferans), Nematoda (round worms), Nematomorpha (horsehair worms), Priapulida (priapulids).
	329) Platyzoa Superphylum ''Gnathifera'' evolves. This includes the 5 Phyla: Gnathostomulida (gnathostomulids), Cycliophora (cycliophorans), Micrognathozoa, Rotifera (rotifers), Acanthocephala (acanthocephalans).
547,000,000 YBN	331) The Protostome Infrakingdom Lophotrochozoa evolves. This includes brachiopods, bryozoans, clams, squids and octopuses (cephalopods), and snails. This infrakingdom is made of: Superphylum Lophophorata, Phylum Bryozoa (bryozoans), Phylum Entoprocta (entoprocts), Superphylum Eutrochozoa.
	332) The Lophotrochozoa Superphylum Lophophorata evolves. This includes the two Phyla Phoronida (phoronids) and Brachiopoda (brachiopods [clams, oysters, muscles]).
	333) The Lophotrochozoa Phyla Phoronida (phoronids) evolves.
	334) The Lophotrochozoa Phylum Brachiopoda (brachiopods [clams, oysters, muscles]) evolves.
545,000,000 YBN	335) The Lophotrochozoa Phylum Entoprocta (entoprocts) evolves.
543,000,000 YBN	53) End Precambrian Eon, start Phanerozoic Eon. End Proterozoic Era, start Paleozoic Era.
	104) The Platyzoa Phyla Platyhelminthes (flatworms) and Gastrotricha (gastrotrichs) evolve.
	120) Start Cambrian period (543-490 mybn).
	336) The Lophotrochozoa Phylum Bryozoa (Bryozoans or moss animals) evolves.
	337) The Ecdysozoa Superphylum Panarthropoda (Arthropods, Onychophora, Tardigrada) evolves.
	338) The Ecdysozoa Phylum Arthropoda (insects, crustaceans) evolve.
	339) The Ecdysozoa Phylum Onychophora (onychophorans) evolves.
	340) The Ecdysozoa Phylum Tardigrada (tardigrades) evolves.
542,000,000 YBN	131) First shell (or skeleton) evolves.
541,000,000 YBN	102) The Lophotrochozoa Superphylum Eutrochozoa (molluscs, ribbon, peanut, spoon, and segmented worms) evolves.
	132) Archaeocyatha (early sponges) evolve.
	341) The Lophotrochozoa Phylum Nemertea (ribbon worms) evolves.
540,000,000 YBN	133) Earliest trilobite fossil.
539,000,000 YBN	342) The Lophotrochozoa Phylum Mollusca (brachiopods, bryozoans, clams, mussels, squids and octopuses [cephalopods], and snails) evolves.
537,000,000 YBN	343) The Lophotrochozoa Phylum Annelida (segmented worms) evolve.
	344) The Lophotrochozoa Phylum Sipuncula (peanut worms) evolve.
530,000,000 YBN	350) Deuterstome Chordata Subphylum Vertebrata evolves. This Subphylum contains most fish, all amphibians, reptiles, and mammals.
	351) Subphylum Vertebrata jawless fish (agnatha) evolve.
	386) Oldest fossil vertebrate and fish. Haikouichthys ercaicunensis: About 25 mm in length.
520,000,000 YBN	148) Hexactinellid sponge from the Hetang Formation, Southern China.
	205) Dinoflagellate biological markers measured in Kopli quarry, Tallinn, Estonia.
507,000,000 YBN	140) Aysheaia (onychophoran, also described as lobopod) fossil, from Burgess shale.
	142) Hallucigenia fossil, from Burgess shale.
	145) Priapulid worm fossils of Burgess Shale.
	146) Opabinia fossils of Burgess Shale.
	147) Animalocaris fossils of Burgess Shale.
	149) Marrella (Arthropod) fossils in Burgess Shale.
505,000,000 YBN	74) Oldest fossil of an artropod moulting.
500,000,000 YBN	230) Ascomycota Fungi ''Pyrenomycetes'' (head scab fungus, orange bread mold, rice blast fungus) and ''Plectomycetes'' (aspergillus, penicilin fungus, coccidiodomycosis fungus) evolve.
490,000,000 YBN	121) Start Ordovician (490-443 mybn), end Cambrian period (543-490 mybn).
475,000,000 YBN	90) Genetic comparison shows the ancestor of all plants (Kingdom Plantae) evolving at this time (in the view that algae are protists and not plants). Genetic comparison shows the ancestor of all plants (Kingdom Plantae) evolving at this time (in the view that algae are single and multicellular protists and not plants).
	232) Genetic comparison shows the non-vascular plant and vascular plant lines splitting now.
	233) Genetic comparison shows Liverworts (Plant Division Marchantiophyta) evolving now.
	244) Genetic comparison shows non-vascular plants (Bryophytes) (Liverworts, Hornworts, Mosses) evolving now. Many people view these plants and the beginning of the Plant kingdom and algae as being in the Protista kingdom. These plants lack vascular tissue that circulates liquids. They neither flower nor produce seeds, reproducing via spores. The order these three divisions evolved in is not fully known.
	352) Subphylum Vertebrata jawless fish lampreys and hagfish lines separate.
470,000,000 YBN	234) Genetic comparison shows Hornworts (division Anthocerotophyta) evolving now.
464,000,000 YBN	398) Earliest fossil spore belonging to land plants. These spores look like the spores of living liverworts.
460,000,000 YBN	84) Earliest fungi fossil.
	235) Genetic comparison shows Mosses (division Bryophyta) evolving now.
	353) Jawed vertebrates (Infraphylum Gnathostomata) evolve. This large group includes all jawed fish, all amphibians, reptiles, and mammals.
	354) Jawed vertebrate (Infraphylum Gnathostomata) Class Chondrichthyes (cartilaginous fishes) evolve.
450,000,000 YBN	106) First chordates. The Chordata phylum includes all tunicates, fishes, amphibians, reptiles, birds, and mammals. The living chordate with the oldest DNA design are tunicates.
443,000,000 YBN	122) Start Silurian period (443-417), end Ordovician period (490-443 mybn).
440,000,000 YBN	360) In the Jawed Fishes, the Ray-finned fishes (Subclass Actinopterygii) evolve. Ray-finned fishes (Subclass Actinopterygii) are in Class Osteichthyes.
428,000,000 YBN	401) Oldest fossil of vascular land plants, Cooksonia. Oldest fossil of vascular land plants, Cooksonia pertoni. They have been found in an area stretching from Siberia to the Eastern USA, and in Brazil. They are found mostly in the area of Euramerica, and most of the type specimens are from Britain. Cooksonia were very small plants, only a few centimetres tall, and had a simple structure: They didn't have leaves, flowers or seeds. They had a simple stalk, that branched a few times. Each branch ended in a sporangium, a rounded structure that contained the spores. No specimen has been found attached to roots. Either it connected to the ground with very fine root hairs, the fossils are of fragments, or something entirely unanticipated. Some specimens have a dark stripe in the centre of their stalks which is interpreted as being the remains of water carrying tissue. Not all specimens have this stripe, either some Cooksonia lacked vasular tissue, or it was destroyed in the fossilization process.
	402) Oldest fossil land animal, the millipede Pneumodesmus.
425,000,000 YBN	377) Coelacanths evolve. 2 living species known.
417,000,000 YBN	123) Start Devonian period (417-354 mybn), end Silurian period (443-417 mybn).
	378) Lungfishes evolve.
412,000,000 YBN	403) Oldest fossil lung fish.
409,000,000 YBN	404) Oldest fossil shark.
400,000,000 YBN	85) Earliest lichen fossil.
	236) Genetic comparison shows the oldest line of living vascular plants from the Division ''Lycophyta'' evolving now. Genetic comparison shows the oldest line of living vascular plants (Tracheophytes) from the Division ''Lycophyta'' evolving now.
	399) Earliest fossil of an insect. This fossil also could have been winged.
390,000,000 YBN	355) Cartilaginous Fishes (Class Chondrichthyes) Subclass Subterbranchialia and Subclass Elasmobranchii (shark-like fishes) separate.
	356) Subclass Subterbranchialia Superorder Holocephali (chimaeras: eg. elephant fish) evolves.
380,000,000 YBN	243) Genetic comparison shows the Fern line and the line that leads to Seed Plants (Gymnosperms and Angiosperms) separating now.
	246) Genetic comparison shows the Spore producing and Seed producing plant lines separating now. Genetic comparison shows the Spore producing (ferns and all earlier plants) and Seed producing (Spermatophyta, Gymnosperms and Angiosperms) plant lines separating now.
	405) Oldest fossil large trees. First forests.
	406) Oldest fossil spider.
375,000,000 YBN	407) Oldest fossil amphibian, and land vertebrate. Oldest fossil amphibian, Acanthostega , from Greenland Also, the oldest evidence of land vertebrates.
360,000,000 YBN	237) Genetic comparison shows Ferns (Plant Division ''Pteridophyta'') evolving now. Genetic comparison shows the Plant Division ''Pteridophyta'' (Ferns) evolving now. Whisk and Ophioglossiod ferns, Marattiod ferns, Horsetails, Lepto. ferns.
	408) Devonian mass extinction caused by ice age.
354,000,000 YBN	124) Start Carboniferous period (354-290 mybn), end Devonian period (417-354 mybn).
350,000,000 YBN	361) In the Ray-finned fishes Superdivision Chondrostei (sturgeons and paddlefish) evolves.
	362) In the Ray-finned fishes Infradivsion Cladistia (Bichirs) evolves.
340,000,000 YBN	379) Tetrapods evolve. (Superclass Tetrapoda)
	380) Amphibians (Caecillians, frogs, toads, Salamanders) evolve. (Superclass Tetrapoda, Class Amphibia)
330,000,000 YBN	409) Oldest fossil conifer.
325,000,000 YBN	381) The Amphibians Caecillians evolve. (Superclass Tetrapoda, Class Amphibia)
320,000,000 YBN	238) Genetic comparison shows the oldest living Gymnosperms from the Plant Kingdom evolving now. Genetic comparison shows the oldest living Gymnosperms (Greek for ''Naked Seed''), Cycads, from the Plant Kingdom evolving now. These are the first seed bearing plants. Gymnosperm Plant Divisions are: Pinophyta � Conifers ''Pinaceae'' 220 ''Other conifers'' 400 species Ginkgophyta � Ginkgo 1 species Cycadophyta � Cycads 130 species Gnetophyta � Gnetum, Ephedra, Welwitschia 80 species
318,000,000 YBN	242) Genetic comparison shows the Gymnosperms and Angiosperms lines separating now.
315,000,000 YBN	410) Oldest fossil reptile. Hylonomus was a small lizard-like reptile that was trapped in the trunk of a swamp tree in what is now Nova Scotia , Canada.
	411) Oldest fossil of flying insect (mayfly?). Oldest fossil of flying insects (unless Devonian Rhyniognatha had wings). Fossil wings on giant mayflies, dragonflys, and dragonfly-like arthropods.
	453) Allegheny mountains form as a result of the collision of Europe and eastern North America.
310,000,000 YBN	384) Egg evolves. This group, the Amniota, will branch into the 3 major Classes: Reptiles (Sauropsida), Birds (Aves), and Mammals (Synapsida).
	385) Reptiles evolve.
305,000,000 YBN	382) The Amphibians Frogs and Toads evolve. (Superclass Tetrapoda, Class Amphibia)
	383) Amphibians Salamanders evolve. (Superclass Tetrapoda, Class Amphibia)
300,000,000 YBN	387) Turtles, Tortoises and Terrapins evolve.
290,000,000 YBN	125) Start Permian period (290-248 mybn), end Carboniferous period (354-290 mybn).
	239) Genetic comparison shows the second oldest living Gymnosperm, Ginkgo from the Plant Kingdom evolving now.
280,000,000 YBN	388) Anapsids (iguanas and snakes) and diapsids (crocodiles) separate.
270,000,000 YBN	240) Genetic comparison shows the third oldest living Gymnosperms, Conifers (Plant division ''Pinophyta'') evolving now.
260,000,000 YBN	363) In the Ray-finned fishes Infradivision Actinopteri evolves.
	364) In the Ray-finned fishes Infradivision Actinopteri, Gars evolve.
255,000,000 YBN	389) Tuataras evolve.
251,000,000 YBN	452) The supercontinent Pangea forms.
250,000,000 YBN	241) Genetic comparison shows the fourth oldest living Plant Division ''Gnetales'' evolving now.
	396) The Permian mass extinction event happens. This is the most devastating mass extinction event in the history of earth. Trilobites become extinct.
248,000,000 YBN	54) End Paleozoic Era, start Mesozoic Era.
	126) Start Triassic period (248-206 mybn), end Permian period (290-248 mybn).
245,000,000 YBN	392) Crocodiles, allegators, caimans evolve.
	393) Birds evolve.
240,000,000 YBN	365) Actinopteri Superdivision Neopterygii evolves.
	366) In Superdivision Neopterygii, Subdivision Halecomorphi, Bow fish (Amiiformes) evolve.
	367) Bow fish evolve. In Superdivision Neopterygii, Division Halecostomi, Subdivision Halecomorphi, Bow fish (Amiiformes) evolve.
228,000,000 YBN	412) Oldest dinosaur fossil, Eorapter was found in South America. Oldest dinosaur fossil. Eoraptor was found in South America . This little dinosaur was a cat-sized meat eater.
220,000,000 YBN	400) Oldest mammal fossil. This is a fingernail-sized skull found in Texas.
215,000,000 YBN	428) Oldest Pterosaur fossil.
210,000,000 YBN	368) Subdivision Teleostei (eels, herrings, anchovies, carp, minnows, piranha, salmon, trout, pike, perch, seahorse, cod) evolves. In Superdivision Neopterygii, Division Halecostomi, Subdivision Halecomorphi, Bow fish (Amiiformes) evolve.
	369) Bonytongues evolve. In Subdivision Teleostei Bonytongues evolve.
	390) Iguanas, chamaeleons, spiny lizards evolve.
	391) Snakes, Skinks, Geckos evolve.
	413) Oldest turtle fossil. Oldest turtle fossil, Proganochelys.
209,500,000 YBN	489) Triconodonta (extinct mammals) evolve.
206,000,000 YBN	127) Start Jurassic period (206-144 mybn), end Triassic period (248-206 mybn).
200,000,000 YBN	370) Eels and tarpons (Elopocephala) evolve. In Subdivision Teleostei Eels and tarpons (Elopocephala) evolve.
199,000,000 YBN	414) End of Triassic mass extinction, because of climate (temperature?, weather?) changes. Large outpourings of lava from break-up of Pangea may have caused climate change. 50% of life went extinct, including thecodonts and synapsids.
190,000,000 YBN	357) Subclass Elasmobranchii (shark-like fishes) divides into 2 divisions Squalea (rays, skates) and Galeomorphii (great white, hammerhead, nurse, sand tiger sharks).
	358) Division Squalea (rays, skates) evolve.
	359) Division Galeomorphii (great white, hammerhead, nurse, sand tiger sharks) evolve.
	371) Herrings and anchovies evolve. Herrings and anchovies (Division Clupeomorpha) evolve.
	563) Homo Ergaster evolves in Africa.
185,000,000 YBN	194) Oldest diatom (Heterokonts or Chromalveolates) fossils.
180,000,000 YBN	456) First mammals, Monotremes evolves. Monotremes lay eggs and are the oldest warm blooded species of record. Order: Monotremata (C.L. Bonaparte, 1837) or Subclass Prototheria (Gill, 1872:vi)
175,000,000 YBN	245) Genetic comparison shows the most ancient flowering plant (Angiosperm) still alive, ''Amborella'' evolving now. This begins the ''broad-leaf'' plants. There is only 1 species of Amborella still living. Angiosperms (flowering plants) are the first plant to produce fruits. A fruit is the ripened ovary, together with seeds, of a flowering plant. In many species, the fruit incorporates the ripened ovary and surrounding tissues. Fruits are the means by which flowering plants disseminate seeds. Class is ''Palaeodicots''?
170,000,000 YBN	372) Carp, minnows, Piranhas evolve.
	373) Salmon, Trout, Pike evolve.
165,000,000 YBN	247) Genetic comparison shows the second oldest line of Angiosperms, the Water Lilies (''Nymphaeales'') evolving now. 70 species.
150,000,000 YBN	374) Lightfish and Dragonfish evolve.
	394) Oldest bird fossil, Archaeopteryx. The Archaeopteryx fossil is from the Solnhofen Limestone of the Upper Jurassic of Germany. Archaeopteryx is a member of the extinct Subclass Archaeornithes. There are many unsolved questions about birds. Did birds evolve flight from trees or from the ground? From what part of the body did feathers evolve? What colors were the first birds? Was Archaeopteryx warm blooded?
	395) Bird Confuciusornis fossil. Unlike Archaeopteryx, Confuciusornis had no teeth.
	562) Oldest Homo Ergaster near-complete hominid skeleten (Turkana Boy) from East Africa.
146,000,000 YBN	490) Multituberculata (extinct major branch of mammals) evolve.
145,000,000 YBN	415) Oldest flower fossil. Oldest flower fossil, Archaefructus, in China, a submerged wetland plant.
144,000,000 YBN	128) Start Cretaceous period (144-65 mybn), end Jurassic period (206-144 mybn).
140,000,000 YBN	457) Marsupials evolve.
	458) Metornithes (early birds) evolve.
138,000,000 YBN	459) Ornithothoraces (early birds) evolve.
136,000,000 YBN	460) Enantiornithes (early birds) evolve.
134,000,000 YBN	461) Ornithurae (early birds) evolve.
132,000,000 YBN	462) Hesperornithiformes (early birds) evolve.
130,000,000 YBN	375) Perch, Plaice, seahorses evolve.
	376) Cod, hake, anglerfish evolve.
128,000,000 YBN	248) Genetic comparison shows the Angiosperm ''Austrobaileyales'' evolving now.
	249) Genetic comparison shows the Angiosperm ''Chloranthaceae'' evolving now.
	250) Genetic comparison shows the Angiosperm group ''Magnoliids'' evolving now.
	251) Genetic comparison shows the Angiosperm ''Ceratophyllaceae'' evolving now.
	252) Genetic comparison shows the Angiosperm group ''Monocotyledons'' (Monocots) evolving now. Monocots are the second largest lineage of flowers after the Eudicots, and include lilies, palms, orchids, and grasses. Monocots are the second largest lineage of flowers after the Eudicots (formally Dicotyledons) with 70,000 living species (20,000 species of orchids, and 15,000 species of grasses). The two main orders of Monocots are ''Base Monocots'' and ''Commelinids''. All the grasses on earth come from this line of flowers (check). Base Monocots (Family Petrosaviaceae) Acorales Alismatales Asparagales (asparagus, onion, garlic, chives, agave, yucca, aloe, hyacinth, orchids, iris, saffron) Dioscoreales (yam) Liliales (lillies) Pandanales Commelinids (Family Dasypogonaceae) Arecales (palms,date palm, rattan, coconut) Commelinales Poales (grasses: maize [corn], rice, barley, oat, millet, wheat, rye, sorghum, sugarcane, bamboo, grass, pineapple, water chestnut, papyrus [many alcohols, breads]) Zingiberales (cardamom, tumeric, myoga, banana, ginger, arrowroot)
	253) Genetic comparison shows the Angiosperm group Eudicots (includes most former dicotyledons) evolving now. Eudicots are the largest lineage of flowers. eudicots are also called ''tricolpates'' which refers to the structure of the pollen. The two main groups are the ''rosids'' and ''asterids''.
	254) Genetic comparison shows the Angiosperm ''Basal Eudicots'' evolving now.
	255) Genetic comparison shows the Angiosperm groups ''Asterids'' and ''Rosids'' evolving and separating now.
	256) Genetic comparison shows the Angiosperm ''Basal Rosids'' evolving now.
	257) Genetic comparison shows the Angiosperm ''Eurosids I'' evolving now.
	258) Genetic comparison shows the Angiosperm ''Eurosids I'' Order ''Celastrales'' evolving now.
	259) Genetic comparison shows the Angiosperm ''Eurosids I'' Order ''Malpighiales'' evolving now.
	260) Genetic comparison shows the Angiosperm, ''Eurosids I'' Order ''Oxalidales'' evolving now.
	261) Genetic comparison shows the Angiosperm, ''Eurosids I'' Order ''Fabales'' evolving now.
	262) Genetic comparison shows the Angiosperm, ''Eurosids I'' Order ''Rosales'' evolving now.
	263) Genetic comparison shows the Angiosperm, ''Eurosids I'' Order ''Cucurbitales'' evolving now.
	264) Genetic comparison shows the Angiosperm, ''Eurosids I'' Order ''Fagales'' evolving now.
	265) Genetic comparison shows the Angiosperm ''Monocotyledon'' (Monocot) group ''Base Monocots'' evolving now.
	266) Genetic comparison shows the Angiosperm ''Monocotyledon'' (Monocot) group ''Commelinids'' evolving now. Commelinids Arecales (palms,date palm, rattan, coconut) Commelinales Poales (grasses: maize [corn], rice, barley, oat, millet, wheat, rye, sorghum, sugarcane, bamboo, grass, pineapple, water chestnut, papyrus [many alcohols, breads]) Zingiberales (cardamom, tumeric, myoga, banana, ginger, arrowroot) (Family Dasypogonaceae) (new order?)
	267) Genetic comparison shows the Angiosperm ''Core Eudicots'' evolving now. Includes carnation, cactus, caper, buckwheat, rhubarb, sundew, venus flytrap, pitcher plants [old world], beet, quinoa, spinach, currant, sweet gum, peony, with-hazel, mistletoe, grape.
	268) Genetic comparison shows the Angiosperm ''Eurosids I'' Order ''Zygophyllales'' evolving now.
	269) Genetic comparison shows the Angiosperm ''Eurosids II'' evolving now.
	270) Genetic comparison shows the Angiosperm ''Eurosids II'' Order ''Brassicales'' evolving now.
	271) Genetic comparison shows the Angiosperm ''Eurosids II'' Order ''Malvales'' evolving now.
	272) Genetic comparison shows the Angiosperm ''Eurosids II'' Order ''Sapindales'' evolving now.
	273) Genetic comparison shows the Angiosperm ''Basal Asterids'' evolving now.
	274) Genetic comparison shows the Angiosperm ''Basal Asterids'' Order ''Cornales'' evolving now.
	275) Genetic comparison shows the Angiosperm ''Basal Asterids'' Order ''Ericales'' evolving now.
	276) Genetic comparison shows the Angiosperm ''Euasterids I'' evolving now.
	277) Genetic comparison shows the Angiosperm ''Euasterids I'' order ''Garryales'' evolving now.
	278) Genetic comparison shows the Angiosperm ''Euasterids I'' order ''Solanales'' evolving now.
	279) Genetic comparison shows the Angiosperm ''Euasterids I'' order ''Gentianales'' evolving now.
	280) Genetic comparison shows the Angiosperm ''Euasterids I'' order ''Lamiales'' evolving now.
	281) Genetic comparison shows the Angiosperm ''Euasterids I'' (unplaced) family ''Boraginaceae'' evolving now.
	282) Genetic comparison shows the Angiosperm ''Euasterids II'' order ''Aquifoliales'' evolving now.
	283) Genetic comparison shows the Angiosperm ''Euasterids II'' order ''Apiales'' evolving now.
	284) Genetic comparison shows the Angiosperm ''Euasterids II'' order ''Dipsacales'' evolving now.
	285) Genetic comparison shows the Angiosperm ''Euasterids II'' order ''Asterales'' evolving now.
120,000,000 YBN	463) Neornithes (modern birds) evolve. More important anatomical characteristics include horn beak; teeth absent; fused limb bones. In addition Neornithes have a fully-separated four-chambered heart and typically exhibit complex social behaviors.
112,000,000 YBN	481) Steropodon galmani, an extinct monotreme, the earliest platypus-like species, lives.
110,000,000 YBN	416) Sauroposiedon, a long-neck brachiosaur (sauropod) fossil. Sauroposiedon fossil, a long-neck (sauropod) brachiosaur from Oklahoma, possibly the tallest animal of all time, at an estimated height of 60 feet.
105,000,000 YBN	417) Argentinosaurus, a long-neck titanosaur (sauropod) fossil. Argentinosaurus, a long-neck (sauropod) titanosaur from South America, possibly the longest animal of all time, at an estimated 130 to 140 feet length.
	491) Afrotheres (elephants, manatees, aardvarks) evolve.
100,000,000 YBN	418) Carnotaurus fossil, a horned, meat-eating (theropod) dinosaur from South America. Carnotaurus fossil, a horned, meat-eating (theropod) dinosaur from South America. The fossil includes skin impressions of its face.
	464) Tinamiformes (modern birds) evolve. More important anatomical characteristics include horn beak; teeth absent; fused limb bones. In addition Neornithes have a fully-separated four-chambered heart and typically exhibit complex social behaviors.
	465) Ratites (ostrich, emu, cassowary, kiwis) evolve.
	480) Kollikodon ritchiei, an extinct monotreme lives.
95,000,000 YBN	419) Spinosaurus fossil, perhaps the largest meat-eating dinosaur, estimated to have been 45 to 50 feet long. Spinosaurus fossil, perhaps the largest meat-eating dinosaur, estimated to have been 45 to 50 feet long. The only skeleton ever found was destroyed during World War 2.
	498) Xenarthrans (Sloths, Anteaters, Armadillos) evolve.
85,000,000 YBN	466) Galliformes (Chicken, Duck, Goose, Turkey, Pheasants, Peacocks, Quail) evolve.
	467) Anseriformes (water birds) evolve.
	499) Laurasuatheres evolve. This is a major line of mammals that include: bats, camels, pigs, deer, sheep, hippos, whales, horses, rhinos, cats, dogs, bears, seals, walrus).
84,000,000 YBN	454) Laramide (Rocky) mountains form.
82,000,000 YBN	420) Hadrosaurs, duck-billed dinosaurs are common. Duck-billed dinosaurs (hadrosaurs) were common like Corythyosaurus , Edmontosaurus , Lambeosaurus , Maiasaurus , and Parasaurolophus . Maiasaurs are examples of dinosaurs from which fossil nests, eggs, and baby dinosaurs have been found.
	500) Shrews, moles, hedgehogs (Laurasuatheres) evolve.
80,000,000 YBN	421) Protoceratops, an early shield-headed (ceratopsian) dinosaur fossil. Protoceratops, an early shield-headed (ceratopsian) dinosaur fossil. It was the first dinosaur discovered with fossil eggs. These eggs and nests were found in Mongolia in the 1920's.
	422) Raptor (dromaeosaur) fossils. Raptors (dromaeosaurs) are Cretaceous dinosaurs, which had large, hook claws on their feet. Velociraptor is one example. The most famous Velociraptor is a skeleton preserved in combat with a Protoceratops from Mongolia, China .
	482) American and true opossums (American Marsupials) evolve. This is the Marsupial Order Didelphimorphia.
	501) Bats (Laurasuatheres) evolve.
78,000,000 YBN	502) Camels, Pigs, Deer, Sheep, Hippos, Whales (Laurasuatheres) evolve.
77,000,000 YBN	483) Shrew opossums (American Marsupials) evolve. This is the Marsupial Order Paucituberculata. 6 surviving species confined to Andes mountains in South America.
76,000,000 YBN	503) Horses, Tapirs, Rhinos (Laurasuatheres) evolve.
75,000,000 YBN	204) Oldest fossil of testate amoeba from Grand Canyon, USA.
	423) Ceratopsian (shield-headed) dinosaurs are common. Ceratopsian (shield-headed) dinosaurs were common in the late Cretaceous. Examples are Monoclonius , and Styrakosaurus . Triceratops, which lived at the end of Cretaceous, was the largest of its kind, reaching 30 feet in length.
	492) Aardvark (Afrotheres) evolves.
	504) Cats, Dogs, Bears, Weasels, Hyenas, Seals, Walruses (Laurasuatheres) evolve.
	505) Pangolins (Laurasuatheres) evolve.
	506) Euarchontoglires evolve. This is a major line of mammals that includes rats, squirrels, rabbits, lemurs, monkeys, apes, and humans.
73,000,000 YBN	484) Bandicoots and Bilbies (Australian Marsupials) evolve. This is the Marsupial Order Peramelemorphia.
70,000,000 YBN	424) Two of the largest meat-eating dinosaurs of all time exist. Tyrannosaurus rex is the top predator in North America and Giganotosaurus is in South America.
	425) Ankylosaurs (shield back and/or club tails) evolve. The armored ankylosaurs (had a shield back or clubbed tail) was the most heavily armored land-animals in the history of earth. These plant-eating were low to the ground for optimal protection. Many had spikes that stuck out from their bone-covered back. Ankylosaurus even had bony plates on its eyelids.
	426) Mososaurs, sea serpents evolve.
	493) Tenrecs and golden moles (Afrotheres) evolve.
	494) Elephant Shrews (Afrotheres) evolve.
	507) The ancestor of all rabbits, hares and pikas evolve.
	516) The ancestor of Tree Shrews and Colugos evolves.
65,500,000 YBN	397) End of Cretaceous mass extinction event happens. Dinosaurs become extinct. Also called the K-T (Kretaceous-Tertiary) extinction. Huge amounts of lava erupted from India, and a comet or meteor collided with the Earth in what is now the Yucatan Peninsula of Mexico. No large animals survived on land, in the air, or in the sea.
65,000,000 YBN	55) End Mesozoic Era, start Cenozoic Era.
	129) Start Tertiary period (65-1.8 mybn), end Cretaceous period (144-65 mybn).
	427) Largest Pterasaur, Quetzalcoatlus evolve. Pterasaurs, the flying reptiles of the Mesozoic reached their largest size with Quetzalcoatlus, which had a wing span of 40 ft. This was the largest flying animal of all time.
	429) Rapid increase in new species of fossil mammals after the extinction of the dinosaurs. Most early Cenozoic mammal fossils are small.
	468) Gruiformes (cranes and rails) evolve.
	470) Strigiformes (owls) evolve.
	485) Marsupial moles (Australian marsupials) evolve. This is the Marsupial Order Peramelemorphia.
	486) Tasmanian Devil, Numbat (Australian marsupials) evolve. This is the Marsupial Order Dasyuromorphia.
	487) Monita Del Monte (Australian marsupial) evolves. This is the Marsupial Order Microbiotheria.
	488) Wombats, Kangeroos, Possums, Koalas (Australian marsupials) evolve. Genetic comparison show Wombats, Kangeroos, Possums, Loalas (Australian marsupials) evolve. This is the Marsupial Order Diprotodontia.
	508) The ancestor of all rats, mice, gerbils, voloes, lemmings, and hamsters evolves.
	509) The ancestor of all Beavers, Pocket gophers, Pocket mice and kangaroo rats evolves.
	807) Cetardiodactyla branch. The ancestor of camels and llamas splits with the ancestor of the rest of the Even-Toed Ungulates (Cetardiodactyla/Artiodactyla: pigs, ruminants, hippos, dolphins and whales). This is just after death of dinosaurs. Both these ancestors are still small and probably look like shrews.
63,000,000 YBN	510) The ancestor of all Springhares and Scaly-tailed Squirrels evolves.
	517) The ancestor of Lemurs evolves.
	587) Primates evolve. Most likely in Africa or the Indian subcontinent.
	588) Widespread appearance of primates starts at base of Eocene.
62,000,000 YBN	495) Elephants (Afrotheres) evolve.
60,000,000 YBN	430) In South America, Andes mountians begin to form.
	431) Oldest fossil rodent.
	432) Creodont, cat-like species, like Oxyaena are common.
	586) Oldest potential primate fossil in Morocco. Genus Altialasius , known only from several isolated teeth.
	796) Largest terrestrial carnivorous mammal yet found, Andrewsarchus skull dates from now [verify]. Andrewsarchus lived 60-32 mybn.
	808) The ancestors of pigs splits from the line that leads to the Ruminants (cattle, goats, sheep, giraffes, bison, buffalo, deer, wildebeast, antelope), hippos, dolphins, and whales.
59,000,000 YBN	496) Hyraxes (Afrotheres) evolve.
	497) Manatees and Dugong (Afrotheres) evolve.
58,000,000 YBN	511) The ancestor of all Dormice, Mountain Beaver, Squirrels and Marmots evolves.
	524) Primate Tarsiers evolve.
57,000,000 YBN	433) Oldest hooved mammal fossil. This is the ancestor of all hooved mammals, including cows, deer, horses and pigs.
55,000,000 YBN	435) Unitatherium are largest land animals.
	436) Oldest horse fossil. Oldest fossil horse, Hyractotherium , the oldest horse was tiny, about the size of a dog).
	512) Gundis evolves.
	809) Lines that lead to Ruminants and Hippos split.
54,970,000 YBN	434) Oldest primate skull. From the Hunan Province, China. Other fossils from the same genus are found in Europe. the earliest euprimates can be distinguished as Cantius, Donrussellia and Teilhardina.
54,000,000 YBN	810) The line that leads to Hippos and the line to dolphins and whales split.
53,500,000 YBN	812) Oldest fossils of dolphins and whales semiaquatic ''Pakicetus''.
51,000,000 YBN	513) OW Porcupines evolve.
50,000,000 YBN	437) Oldest elephant fossil. Oldest elephant fossil, an unnamed fossil from Algeria.
	438) Himalayan mountains start to form as India collides with Eurasia. This will continue for millions of years.
	518) Primates Lorises, Bushbabbies, Pottos evolve.
	816) Oldest Ambulocetus (early whale) fossil.
49,000,000 YBN	439) The largest meat-eating land animals of the Paleocene and Eocene epochs were flightless birds, like Diatryma from America , and Gastornis from Europe.
	472) Caprimulgiformes (nightjars, night hawks, potoos, oilbirds) evolve.
	474) Falconiformes (falcons, hawks, eagles, Old World vultures) evolve.
	514) African mole rats, cane rates, dassle rats evolve.
	515) NW porcupines, guinea pigs, agoutis, capybara evolve.
46,000,000 YBN	817) Oldest Rodhocetus (early whale) fossil.
45,000,000 YBN	519) Primate Aye-aye evolves.
40,000,000 YBN	440) In Europe the Alpines start to form.
	441) Oldest fossil of Miacis, a weasel-like ancestor of bears and dogs.
	525) The ancestor of all New World Monkeys evolves.
	815) Oldest Basilosaurus (early whale) fossil.
37,000,000 YBN	442) Oldest fossil of dog, Hesperocyon. Oldest fossil of dog, similar to a weasel, Hesperocyon.
	471) Apodiformes (hummingbirds, swifts) evolve.
	473) Coliiformes (mouse birds) evolve.
	475) Cuculiformes (cuckoos, roadrunners, possibly hoatzin) evolve.
	476) Piciformes (woodpeckers, toucans) evolve.
34,000,000 YBN	813) Toothed whales (dolphin, sperm whale, killer whale) and Baleen whales (blue, humpback, gray whale) lines split.
	814) Earliest Baleen whale fossil.
30,000,000 YBN	443) Indrictotherium lives in India, and is the largest land mammal in the history of earth.
	520) Primate True Lemurs evolves.
28,000,000 YBN	477) Passeriformes (perching songbirds) evolve. This Order includes many common birds: crow, jay, sparrow, warbler, mockingbird, robin, orioles, bluebirds, vireos, larks, finches. More than half of all species of bird are passerines. Sometimes known as perching birds or, less accurately, as songbirds, the passerines are one of the most spectacularly successful vertebrate orders: with around 5,400 species, they are roughly twice as diverse as the largest of the mammal orders, the Rodentia. Small to moderately large modern land birds; aegithognathous palate; large brain size and intelligence; unique syringeal anatomy; unique insertion of forearm muscles; tarsi covered with small scales; large, reversed incumbent hallux; anisodactyl foot; hallux independently moveable; plantar tendons; bundled sperm with coiled head; metabolic rates up to 50% higher than comparable non-passarines of same size; complex nest-building behaviors; altricial young; vocal plasticity.
	811) The Dolphin and Whale line split. *see Toothed and baleen split.
27,000,000 YBN	521) Primates Wooly and Leaping Lemurs evolve.
25,000,000 YBN	444) Oldest cat fossil. Oldest cat fossil, Proailurus.
	522) Primates Sportive Lemurs evolve.
	523) Primates Mouse and Dwarf Lemurs evolve.
	531) The two major lines which lead to Old World Monkeys and hominids (lesser and great apes) split. There are 20 surviving genera and around 100 species of Old World Monkey.
24,000,000 YBN	662) Ancestor of all Apes and Hominids loses tail. This may be a genetic mutation or because a tail might be an obstacle for species like gibbons that swing from branch to branch as opposed to more ancient primates that leap from branches. Based on 22my Egyptopithecus fossils which is thought to not have had a tail [check].
23,000,000 YBN	478) Echidnas (monotremes) evolve.
	479) Duck-Billed Platypus (Monotremes) evolve.
22,000,000 YBN	526) Titis, Sakis and Uakaris (New World Monkeys) evolve.
	527) Howler, Spider and Woolly monkeys (New World Monkeys) evolve.
	528) Capuchin and Squirrel monkeys (New World Monkeys) evolve.
	558) Afropithecus evolves in Africa.
	559) Proconsul evolves in East Africa.
	560) Aegyptopithecus evolves in East Africa.
21,000,000 YBN	529) Night (or Owl) monkeys (New World Monkeys) evolve.
	530) Tamarins and Marmosets (New World Monkeys) evolve.
	556) Kenyapithecus evolves in Africa.
20,000,000 YBN	549) The ancestor of all the homonids (Lesser and Great Apes), moves over land from Africa into Europe and Asia. An alternative theory has this ancestor in Africa, with a large number of Africa to Eurasia migrations by later species.
	561) Genetic evidence that complex human language (with perhaps 5 or more sounds) evolves in early Homo species.
18,000,000 YBN	537) Ancestor of all Gibbons (Lesser Ape Hominids) evolves in Eurasia. 12 species of Gibbons.
16,000,000 YBN	555) Oreopithecus evolves in Eurasia (or Africa?).
15,000,000 YBN	553) Lufengpithecus evolves in China.
14,000,000 YBN	532) The Old World Monkey family divides into Cercopithecinae (Macaques and Baboons) and Colobinae (Colobus and Proboscis monkies). There are 20 surviving genera and around 100 species of Old World Monkey.
	542) Orangutans evolve in Asia.
13,000,000 YBN	551) Dryopithecus evolves in Eurasia. (or East Africa?) This is the oldest fossil of the family Hominidae.
	552) Graecopithecus (Ouranopithecus) evolves in India and Pakistan.
10,500,000 YBN	538) Crested Gibbons evolve.
10,000,000 YBN	533) Colobus monkeys (Old World Monkey) evolve.
	534) Langurs and Proboscis monkeys (Old World Monkey) evolve.
	535) Guenons (Old World Monkey) evolve.
	536) Macaques, Baboons, Mandrills (Old World Monkey) evolve.
9,000,000 YBN	550) The ancestor of the Gorilla, Chimpanzee, and archaic humans moves over land from Eurasia back into Africa. Alternatively, this ancestor could have evolved in Africa if many earlier ancestors frequently migrated to Eurasia.
8,000,000 YBN	544) Common ancestor of chimpanzee and human lives in Africa. This is when the line that leads to chimpanzees and the line that leads to humans separates. This date conflicts with genetic comparison which puts this at 6my. There are very few chimpanzee fossils found.
7,750,000 YBN	539) Siamang evolve.
7,000,000 YBN	469) Podicipediformes (grebes) evolve.
	543) Gorillas evolves. in Africa.
	565) ''Toumai'' (genus Sahelanthropus) fossils, possibly the earliest bipedal homonid, found in Chad, central Africa date to this time. There is a conflict between the genetic date of 6 million for the chimpanzee-hominid split, and this and other fossils that indicate that this split was earlier.
6,100,000 YBN	566) Orrorin fossils, perhaps the second oldest hominid ancestor date from this time.
6,000,000 YBN	540) Hylobates Gibbons evolve.
	541) Hoolock Gibbon evolves.
5,800,000 YBN	569) Ardipithicus fossils, a genus of early hominins, dates from this time.
5,500,000 YBN	567) Two-leg walking (bipedalism) evolves in early hominids. Richard Dawkins describes the major theories of why two leg walking evolved from four leg walking: 1) to carry food home, for later use or for others (leopard uses jaw) 2) as an adaption to squat feeding (turning over stones to look for insects) 3) for males to show their penises, and for females to hide their vaginas. I am adding: 4) that walking was a sign of dominance or superiority, perhaps made the body look larger, and a female more sophisticated(?). 5) easier to use hand held weapons (and tools?). Don Johanson hypothesized that as Africa changed from jungle to savannah, hominids had to travel farther for food, thus making two-leg walking more efficient , but this claim is disputed by one experiment by Taylor and Rowntree which indicates that there is no energy gain from 4-leg to 2-leg movement.
5,000,000 YBN	554) Gigantopithecus evolves in China.
4,400,000 YBN	547) Australopithecus evolves. in Africa. Australopithecus afarensis?.
4,000,000 YBN	445) Oldest Australopithecus fossil in Africa.
3,700,000 YBN	570) Laetoli footprints date to this time.
3,500,000 YBN	568) Kenyanthropus fossils date from this time.
3,180,000 YBN	571) Australopithecus afarensis fossil, ''Lucy'', date to this time.
3,000,000 YBN	446) North and South America connect.
2,700,000 YBN	564) Paranthropus, a line of extinct bipedal early homonids evolves in Africa. It is interesting to know that Paranthropus shared the earth with some early examples of the Homo genus, such as H. habilis, H. ergaster, and possibly even H. erectus. Australopithecus afarensis and A. anamenis had, for the most part, disappeared by this time.
2,500,000 YBN	447) Oldest Homo Habilis fossil. This is the earliest member of the genus Homo. This is when the human brain begins to get bigger. Homo habilis is thought to be the ancestor of Homo ergaster. Homo Habilis evolved in Africa. As the habilis brain grows, habilis gains a larger memory.
2,450,000 YBN	589) Homo Habilis evolve smaller, thinner and less body hair. except head hair, facial hair, airpit, chest and genitals. This is thought to be driven by male sexual selection of less haired females, perhaps because less hair meant less body lice aqnd so was more desireable. No other still living apes have taken this direction.
SCIENCE
2,400,000 YBN	455) Oldest formed stone tools. This begins the ''Stone Age'', the Paleolithic (''Old Stone Age'').
2,000,000 YBN	545) Bonobos (Chimpanzees) evolve. in Africa.
	546) Common Chimpanzees evolve. in Africa.
	593) Homo Ergaster leaves Africa into Europe and Asia. Ergaster is the first hominid to leave Africa.
1,800,000 YBN	130) Start Quaternary period (1.8 mybn-now), end Tertiary period (65-1.8 mybn).
	449) Oldest Homo erectus fossil outside of Africa. Homo Erectus evolves from Homo Ergaster in Asia. Homo sapiens have been around for only some 200,000 years, but Homo erectus is thought to have lived for 1 million years from 1.5 million to 500,000 years before now.
	826) End Tertiary period (65-1.8 mybn), start Quaternary period (1.8 mybn-now). This is also the start of the start of Pleistocene (PlISTOSEN) epoch.
1,500,000 YBN	448) Most recent Homo Habilis fossil.
	583) Ealiest evidence of use of fire, from Swartkrans in South Africa.
790,000 YBN	584) Ealiest evidence of controlled use of fire, from Israel. The presence of burned seeds, wood, and flint at the Acheulian site of Gesher Benot Ya`aqov in Israel is suggestive of the control of fire by humans nearly 790,000 years ago. The distribution of the site's small burned flint fragments suggests that burning occurred in specific spots, possibly indicating hearth locations. Wood of six taxa was burned at the site, at least three of which are edible�olive, wild barley, and wild grape.
200,000 YBN	548) Humans (Homo sapiens) evolve in Africa.
	590) This is the beginning of the transition from the verbal language of chimps and monkeys, that will result in the short staccato language humans use now. Either the majority of the 50 basic sounds were learned simulateneously for all sapiens by word of mouth or those 50 basic sounds evolved before the sapiens dispersed throughout eurasia. Since sapiens spread out over Europe and Asia did not develop one language with the same sounds used for each word, it seems unlikely that the 50 basic sounds that are found in all of those languages would not be unified for all sapiens, and that more likely the majority of those sounds evolved in a smaller group in Africa and were then dispersed into Europe, Asia, and then Australia and the Americas. It is difficult to determine when but perhaps Homo sapiens in Africa evolved a larger vocabulary of sounds used to label objects and activities than more ancient primates. These sounds eventually become shortened and more finely controlled, ultimately evolving to become the 50 basic sounds used to construct words in all human languages. These first sounds are probably vowels before any consonents evolve. Perhaps these vowels are: U (food), o (mama), O (no), E (eat) and perhaps i (big), e (bed), u (cup). (These sounds are in use by the first Sumerian writing[3 24].) For centuries early human language may have been vowels only until consonents attached to vowels were regularly used. The first consonents were probably (the so-called ''stop consonents'') T and D, then K and G, then perhaps B and P. But it may be impossible to know the order, and the number of years between the three sound families. Initially, this language is very simple, one sound applying to many objects and situations. Some time near here, words made of more than one sound (compound sounds/words) evolved [how many species evolved the ability of compound sound words?]. Now objects and situations might have compound sounds, although still basically one word. In addition, the skill of imitating sounds becomes better. Clearly many mammals and birds have a vocabulary of remembered sounds, which are used to label other species, objects, and situations. Chimpanzees use sounds that sound similar to sounds humans make, for example the U (in food), and perhaps ''E'', although not succinctly enunciated in short duration breaths. Perhaps there were even other sounds that were lost to the past. If simultaneously learned, this had to happen through inter-tribal trading and interaction which required object name translation. And then those new sounds had to be remembered, accepted, and included into both tribes native language. Because the same sounds exist in all languages, but most languages use different combinations of these 50 sounds to make words, one conclusion is that the individual sounds evolved before the dispersion, because clearly, there was not enough sharing and interaction to make one language for all eurasia, a language where each object is described with a word that has the same sounds. That sapiens could not form a single language, I think is evidence that they probably cold not share sounds easily either, which supports a 50 sounds learned before dispersal throughout eurasia, and ofcourse clearly before dispersal to australia and the americas, since those native people appear to have used the same sounds, although different combinations of sounds for words. Clearly some less common vowel sounds evolved later based on these main sounds, for example ''i'' (big), ''u'' (cup), ''v'' (food), etc.
195,000 YBN	161) Oldest human (Homo sapiens) skull, in Ethiopia, Africa.
190,000 YBN	595) Homo sapiens start to show dramatic increase in creative ability which includes: more diversity in stone tool types, and regular stool tools for specific uses, artifacts carved from bone, antler and ivory in addition to stone burials were accompanied by ritual or ceremony and contained a rich diversity of grave goods living structures and well-designed fireplaces were constructed hunting of dangerous animal species and fishing occurred regularly higher population densities abundant and elaborate art as well as items of personal adornment were widespread raw materials such as flint and shells were traded over large distances
	600) Very uncertain when, but the S, Z, s family of sounds evolves in early sapien language.
170,000 YBN	592) It is very difficult to determine, but at some point the ''L'', ''M'', ''N'', and ''R'' family of sounds were invented by early Homo sapiens presumably in Africa. Sapien language has not yet taken on the present ''staccato'' form of combined short duration sounds, although objects are probably labeled with multi sound words.
160,000 YBN	591) Second oldest human (Homo sapiens) skull, like the oldest in Ethiopia, Africa.
150,000 YBN	601) The short duration family of sounds (B,D,G,K,P,T) evolves in early sapien language. Initially, these sounds may have formed (naturally) before the long vowel sound (for example a ''B'' sound when opening the mouth to howl a vowel sound). This begins the ''short duration'' language, where each sound, including vowels, and open consonents (l,m,n,r) are shortened to short durations. This is basically the form of language all humans use today, short duration (50 ms each) sounds from a family of only 50 sounds, combined together to form words used to describe objects and activities (nouns), movements and actions (verbs), and later a second word added to further describe objects, adjectives.
130,000 YBN	450) Neanderthals evolve from Homo ergaster in Europe and Western Asia. Oldest Neanderthal fossil in Croatia. Neanderthal mitochondrial DNA has been compared to sapiens and a common ancestor of the two is estimated to be 500,000, long before the oldest sapien fossils in Africa, which supports the idea that sapiens did not evolve or interbreed with Neanderthals.
120,000 YBN	572) Wurm glaciation starts.
95,000 YBN [92994 BCE]	594) Homo sapiens move north out of Africa. It is not clear if this is the primary dispersal. Some people think the main sapiens dispersal did not happen until 45,000 ybn. .
92,000 YBN [89994 BCE]	597) Oldest human (Homo sapiens) skull outside Africa, in Israel. The Jebel Qafzeh skull. This may represent an early and presumably short lived movement of early sapiens.
60,000 YBN [57994 BCE]	573) Oldest evidence of humans in Americas, from a rock shelter in Pedra Furada, Brazil.
	577) Sapiens sailing from Southeast Asia reach Australia.
53,300 YBN [51300 BCE]	557) Most recent Homo Erectus fossil in Java. Shows that Homo erectus lived at the same time as Homo sapiens. These ages are 20,000 to 400,000 years younger than previous age estimates for these hominids and indicate that H. erectus may have survived on Java at least 250,000 years longer than on the Asian mainland, and perhaps 1 million years longer than in Africa.
43,000 YBN [41000 BCE]	1187) The oldest known mine, ''Lion Cave'' in Swaziland, Africa is in use.
42,000 YBN [40000 BCE]	596) Oldest Homo sapiens fossil in Australia. ''Mungo Man''
40,000 YBN [38000 BCE]	598) Oldest Homo sapiens fossil in Europe. from the Cro-Magnon site in France 40,000 also marks the decline of Neaderthal populations until their extinction 10,000 years later.
38,000 YBN [36000 BCE]	574) Second oldest evidence of humans in Americas, from Orogrande cave, in New Mexico.
35,000 YBN [33000 BCE]	451) Most recent Neandertal fossil.
32,000 YBN [01/01/30000 BCE]	1262) The Chauvet Cave paintings in Southern France are created and are the oldest known human made paintings.
30,000 YBN [27994 BCE]	575) Mitochondrial DNA shows a sapiens migration to the Americas here.
	599) Oldest Homo sapiens fossil in China. from the Zhoukoudian Cave in China
20,000 YBN [17994 BCE]	576) Y Chromosome DNA shows a sapiens migration to the Americas here.
13,000 YBN [10994 BCE]	578) The earliest bones of a human in the Americas, from the California Channel Islands date to now.
12,500 YBN [10494 BCE]	582) Human artifacts from Monte Verde, southern Chile.
11,500 YBN [9494 BCE]	581) Spear Head from Clovis, New Mexico.
10,706 YBN [8700 BCE]	829) Oldest copper (and metal) artifact, from Northern Iraq. This starts the ''Copper Age'' (Chalcolithic). This is a copper ear ring. Copper is the first metal shaped by humans.
10,000 YBN [01/01/8000 BCE]	1259) Clay tokens of various geometrical shapes are used for counting in Sumer.
9,000 YBN [7000 BCE]	1288) Mehrgarh an Indus Valley neolithic city begins now.
8,600 YBN [6600 BCE]	848) Symbols created on a tortoise shell from a neolithic grave in China may be ancestors of Chinese writing.
8,000 YBN [5994 BCE]	602) Oldest evidence of weaving.
	603) Oldest evidence of pottery.
	604) Oldest evidence of oil lamp.
	605) Oldest dug-out boat in Holland.
	606) Oldest city, Jericho. jericho is located in the West bank, near the Jordan river (east of Mediterranean).
	607) Oldest flint sickle.
	608) Oldest saddle quern (a stone used to grind grain into flour).
	609) Einkorn grown.
	610) Flax grown.
	611) Wheat grown.
	612) Barley grown.
	613) Millet grown.
	614) Bow and arrows invented. Oldest evidence of bow and arrow.
	615) Spear invented. Oldest evidence of spear.
	616) City ''Catal H�y�k''.
	617) Goats kept, fed, milked for milk and killed for food. Goats [check: or dogs?] are oldest domesticated animal.
7,006 YBN [5000 BCE]	627) Oldest evidence of copper melted, and casted [where?].
7,000 YBN [4994 BCE]	618) City of Sumer.
	619) City of Ur.
6,000 YBN [3994 BCE]	830) Oldest iron artifacts, made of iron from meteorites, in Egypt. Some might argue this is the beginning of the Iron Age, but other would start the Iron Age only at smelting and casting of Iron.
5,500 YBN [3494 BCE]	621) Oldest plow.
	622) Oldest evidence of irrigation on earth, in ''middle east'' (east of Mediterranean).
	623) Oldest pottery baked in fire-heated oven.
	624) Oldest baked brick (east of Mediterranean).
	625) Donkey kept, fed and used to transport (and for food?).
	628) Oldest evidence of bronze (copper mixed with tin) melted, and casted [where?]. This begins the ''Bronze Age''. The earliest tin-alloy bronzes date to the late 4th millennium BC in Susa (Iran) and some ancient sites in Luristan (Iran) and Mesopotamia. The earliest evidence of bronze metalworking dates to the mid 4th millennium BC Maykop culture in the Caucasus. The oldest use of Bronze is from Anatolia, not Egypt from 6500 B.C. (''Bronze Age'', Encyclopedia Britannica II, 1982, p. 297.)
	630) 3 cylinders used as a stamp for signature.
	634) Egyptian calendar.
	635) Oldest smelted iron, tiny pieces of smelted iron, in Egypt. This is the start of the Iron Age, as iron becomes more popular because iron is more abundant. in Mesopotamia, Anatolia, and Egypt
	646) The earliest known wheel, a pottery wheel, comes from Mesopotamia. The earliest known wheel, a pottery wheel, comes from Mesopotamia.
	1260) The earliest certain writing on baked clay tablets is invented in Sumer and replaces a clay token counting system. These ''numerical tablets''[15 13] represent the first recorded place value number system (the position of the number is multiplied by a base number), a sexagesimal (base 60) numbering system. This base 60 numbering system will be used continuously to count time, for astronomy, and geography, and is still in use today. The first writing begins as numbers on clay tablets, some also with stamped seals.[15 13-14] This system of writing on clay tablets will evolve into modern written language. Writing was first used to solve simple accounting problems; for example to count large numbers of sheep or bales of hay. Writing may have arisen out of the need for arithmetic and storage of information, but will grow to record and perpetuate stories, myths, epics, songs, and most of what we know about human history. Counting tablets replace the token counting system in Sumer, and represent the first recorded written numbers with place value (the position of the number is multiplied by another number called the base or radix) and the beginning of the sexagesimal (has a base of 60) numbering system. This sexagesimal system is a mixed radix system with an alternating base 6 and base 10. There are dots for number 1 through 9, is first place value numbering system has no symbol for zero. A base-60 numbering system is still used to measure time (60 seconds, 60 minutes, etc), angles, and geographic coordinates. Initially, the commodity counted is not indicated, but will be gradually added to the number system, for example with a seal or drawing (pictograph) of the commodity. In 300 years this will be replaced by tablets with a number to represent quantity and a picture to represent the commodity. This number and picture script will evolve into written language. In this writing, each symbol represent a single object (numeral, noun, pronoun, verb, adjective, or adverb). Symbols sounds are not yet added together to form a single word (phonetic).
	1285) Possibly the earliest known writing, symbols on pottery from Harrapa an Indus Valley civilization.
5,307 YBN [01/01/3300 BCE]	1261) In Sumer, counting tablets evolve into the beginning of pictographic writing. Now along with numbers on the clay tablets are symbols that represent the commodity (such as cows, sheep, and cereals).[4 19] These symbols represent the earliest record of what will become the modern alphabet. These tablets are all economic records, used to keep a record of objects owned or traded, and contain no stories. Writing begins as a method for increasing the human memory to keep track of the many transactions of a city, and not for the purpose of recording or remembering stories. With the beginning of writing, begins the first systematic training and industry of scribes[4 105] and this will ultimately evolve into the modern school system. These symbols are drawn with curved lines which will later be replaced by the easier and faster to draw straight lines and later the wedges of cuneiform.[4 118] The symbol for ox (''gud'' in Sumerian, later ''aleph'' in Egyptian) will become the letter ''A'' (alpha), the symbol for house, (/e/ in Sumerian and /bitum/ in Akkadian [8 36]) will become ''B'' (beta), [t list others: see photo], although this writing is not yet phonetic, each symbol still representing only one word. This writing, taken together with the sounds of this spoken language, provide the earliest evidence of what sounds of the 50 or more basic sounds still in use, were invented before writing. We find that nearly all sounds were invented by this time. In Sumerian are the vowels |i| |e| |o| |v| (possibly |u| |E| |U| and |O|) and the consonents: |D||T|, |B||P|, |G||K|, |Z||S||s|, |L||R| (and |l||m||n||r|), and finally |h| [|t| check], which leaves: the vowels: |a| (cat), |A| (ate), |I| (eye), |v| (umlow), |x| (awe) and the consonents |H|, |C|, |F|, |J|, |t| (three), |z| (the), curled r |q|, |V|, |W|, and |Y| to be invented after this time.[t needs more checking][4 24] Around 1200 symbols have been identified in these ancient texts, around 60 are numerals.[4 25]
5,256 YBN [3250 BCE]	637) Scribe humans in Sumer start writing in rows, left to right (seeing that writing was smudged when writing in columns) Pictures are turned 90 degrees.
5,206 YBN [3200 BCE]	1060) People living in the Indus Valley Civilization are the first to have an oven within each mud-brick house.
5,200 YBN [3200 BCE]	650) Oldest artifact with cuneiform writing, at Uruk[4 116] which is a large city at this time[4 116]. These are clay and stone tablets that have names of humans (thought to be wage lists), lists of objects, plus receipts and memos. Pictures not drawn with pointed reed, but drawn with (diagonally) cut reed-stem pressed in to the wet clay to make wedges. What were pictures (of oxen, etc.) are changed to be made of all single presses, not pictures drawn freehand. This writing contains about 600 unique symbols. Each symbol represents a single word, as a noun (an object or name), verb, adjective?, or adverb? Symbols are most likely not yet combined to form a single word.
	1266) The oldest writing in Egypt yet found dates to now.
5,106 YBN [3100 BCE]	638) An Armenoid or Giza race of humans enter egypt. Skeletal remains show larger than average bones and skulls than the native humans. These humans bring writing to Egpyt.
	639) Oldest hieroglyphic inscriptions ever found in Egpyt. This begins writing in Egpyt. This writing is descended from the first writing in Sumeria.
	641) Second oldest Egyptian Writing (Narmer Palette).
5,006 YBN [3000 BCE]	648) Oldest evidence of sail boat.
	649) Oldest ships made of wood. These ships were used in the Medeterranean.
	651) Akkadian, Babylonian, and Assyrian languages all use cuneiform writing.
	666) Oldest evidence of hemp grown in China.
	667) Oldest evidence of glass making in Egypt.
	668) Oldest evidence of silk making in China.
	669) Evidence of wheel in China.
	671) Oldest evidence of arch in Egypt.
	674) Oldest evidence of chariot in Sumer .
	675) Oldest silver objects, in Ur.
	676) Oldest evidence of melting wax in clay casting (cire-perdu).
5,000 YBN [01/01/3000 BCE]	1265) The proto-cuneiform Sumarian script becomes phonetic (the sounds of symbols are combined to form words).[1 117] This is the beginning of phonetic written language. Evidence of this is the sign /ti/, for ''arrow'' that is now also defined as the Sumarian word for ''life'' /til/ which starts with the same sound.[1 117] After this phonetic abstraction, the introduction of syllabograms (symbols that form syllables of multi-symble words), names and words for which no symbols had existed can be created.[1 117] For example, the symbol originally defined as the Summerian verb ''bal'' (to dig) can also be spelled with the syllabic signs ''ba'' + ''al'', while the Akkadian word for dig (''heru'') sounds differently.[1 117][t show image if possible] The vast majority of Sumerian language is made of one-syllable words.[1 117] Perhaps all earlier spoken languages contained single-syllable words.
4,931 YBN [2925 BCE]	643) Hieratic script, a cursive script of traditional Egyptian hieroglyphs replaces traditional hieroglyphs. Hieratic script was almost always written in ink with a reed pen on papyrus. The word 'hieratikos' means 'priestly' because by the Greco-Roman period this writing was used only by priest humans.
4,636 YBN [2630 BCE]	654) Imhotep, the first architect and doctor of recorded history designs the first pyramid in Egypt. Imhotep was one of the officials of the Pharaoh Djos�r (3rd Dynasty), designed the Pyramid of Djzos�r (Step Pyramid) at Saqqara in Egypt around 2630-2611 BC. He may also have been responsible for the first known use of columns in architecture. His name means the one who comes in peace.
4,600 YBN [2600 BCE]	1269) Earliest known inscription to a king, Enmebaragesi, ruler of Kish.[1 23]
	1271) The oldest known written story, the Sumerian flood story. The oldest known written story (or literature), the Sumerian flood story, the ''Ziusudra epic'' is known from a single fragmentary tablet, writing in Sumerian from Nippur. The first part tells the story of the creation of man, animals and the first cities. In this story the gods send a flood to destroy mankind. The god Enki warns Ziusudra of Shuruppak to build a large boat. A terrible storm rages for seven days and then [t the god] Utu (the sun) appears and Ziusudra sacrifices an ox and a sheep. After the flood An, the sky god, and Enlil, the chief of the gods give Ziusudra ''breath eternal'' and take him to live in Dilmun. The rest of the poem is lost. There are many similarities between the stories of Ziusudra, Atrahasis, Utnapishtim and Noah.
4,506 YBN [2500 BCE]	677) Oldest bronze sickle.
	688) Oldest seed drills in Babylonia.
	689) First animal and vegtable dyes.
	690) Oldest evidence of writing on papyrus.
	691) Oldest evidence of skis used in Skandinavia .
4,413 YBN [2407 BCE]	800) Oldest papyrus, the Prisse Papyrus, in Egypt.
4,100 YBN [2100 BCE]	1279) The earliest medical (health science) text, found in Nippur.[1 52]
4,050 YBN [2050 BCE]	1278) The earliest recorded laws, the Ur-Nammu tablet.[1 52]
4,006 YBN [2000 BCE]	705) Stonehenge built.
	706) Domesticated horses used by people in Asian steppes.
	707) Copper sulphide ores smelted (melted and purified?).
	708) Vellum in Egypt.
	710) Shaduf (Shadoof), an irrigation tool originated in Sumer.
	711) Spoked wheel.
4,000 YBN [2000 BCE]	702) Earliest cotton grown, in Indus Valley.
	703) Earliest kaolin clays used in China.
	704) Earliest evidence horse pulled vehicles.
	733) Oldest lock, found near Nineveh. Oldest lock, found in ruins of the palace of Khorsabad near Nineveh. The lock is made of wood and uses a tumbler design, similar to modern locks. This kind of lock will be used widely in Egypt.
	1286) The earliest known versions of the Gilgamesh (or Gish-gi(n)-mash) story are written in Sumerian on clay tablets.
3,848 YBN [1842 BCE]	712) First all phonetic language and alphabet. Proto-semitic alphabet made in turquoise mines probably by Semitic humans. This alphabet is thought to have replaced cuneiform, and may be root of all other alphabets. This first strictly phonetic alphabet is in use until 1797 BC.
3,656 YBN [1650 BCE]	716) Ahmose, a scribe in egypt, name is in the ''Rhind Mathematical Papyrus'' in a work entitled ''directions for knowing all dark things'' now in located in the British Museum.
3,558 YBN [1552 BCE]	799) Oldest health science document, Ebers papyrus, in Egypt.
3,506 YBN [1500 BCE]	719) Earliest evidence of paddy field rice grown in china.
	720) Corn (maize) grown in America (where?). Earliest evidence of Corn (maize) grown in America (where?).
	723) Oldest simple pulleys used in Assyria.
	724) Composite bows.
	726) Oldest sundial clock in Egypt.
	727) Reed boats in Peru.
3,206 YBN [1200 BCE]	732) Oldest iron tipped plough.
2,856 YBN [850 BCE]	751) Greek humans copy phonetic alphabet language from phoenician humans. Phoenician humans are using a variation of letters used at this time by Semite humans in Syria-Palestine, Canaanite writing. ''Alef'' (ox), ''beth'' (house), ''gimel'' (camel), ''daleth'' (door), etc. are changed to ''alpha'', ''beta'', ''gamma'', ''delta'', etc. The semitic alphabets Hebrew and Arabic are descended from the Canaanite language.
2,806 YBN [800 BCE]	718) ''u'' sound (''cup'', ''run'') is used for first time in Greece.
	818) ''t'' sound (''theta'', ''theater'') is used for first time in Greece.
2,791 YBN [785 BCE]	771) Babylonian astronomers can predict eclipses.
2,706 YBN [700 BCE]	1075) Latin or Etruscan [check] speaking people start using the letter ''C'' (Gamma), not only to represent it's traditional sound ''G'', but also for the sound ''K'', usually reserved for the letter ''K''. This will add confusion to how to pronounce a word, and violates a more simple, logical system where one letter equals only one sound.
2,669 YBN [669 BCE]	1284) Ashurbanipal, systematically collects clay tablets and builds a library.
2,666 YBN [660 BCE]	644) In Egypt, the Demotic script replaces hieratic in most secular writing, but hieratic continued to be used by priests for several more centuries.
2,656 YBN [650 BCE]	1066) Evidence of the earliest aquaduct, a channel used to move water from one place to another, is in Assyria. This aquaduct is built of and carries water across a valley to the capital city, Nineveh.
2,600 YBN [594 BCE]	762) Thales (in Greek: Θαλης) is the first human of record to explain the universe with out using any gods in the explanation, claiming the universe originated as water.
2,586 YBN [580 BCE]	764) Anaximander (Greek: Αναξίμανδρος) (Anaximandros) oNoKSEMoNDrOS or ANAKSEmANDrOS? (610 BC Miletus - 546 BC Miletus) friend and student of Thales. Anaximander thought life originated in water and that humans evolved from fish. This is the first record in history of the theory of evolution. Anaximander is among the first Greek philosophers to use a geocentric system with the earth as a flat cylinder fixed and unmoving in the center, with the sun, moon and stars and actual physical objects attached to rotating crystalline spheres centered around the earth. Presumably Greece and all surrounding places were located on the flat part of the cylinder. [check]
2,551 YBN [545 BCE]	920) Herodotus of Halicarnassus (Greek: Ἡρόδοτος, Herodotos) (484 BCE- c425 BCE), a Greek historian writes ''The Histories'', a collection of stories on different places and peoples he learns about through his travels. It includes the conflict between Greece and Persia.
2,546 YBN [540 BCE]	783) Anaximenes (~570 BC Miletus - ~500BC), possible pupil of Anaximander. Isaac Asimov claimed that Anaximenes was the first to distinguish clearly between planets and stars [check]. Perhaps Anaximenes made the name ''planet'' which translates to ''wanderer'' in Greek. Anaximenes thought that a rainbow is natural phenomenon, and not a goddess, as was the prevailing belief.
	784) Xenophanes (~570 BC - ~480 BC), a Greek philosopher, poet, social and religious critic , learns from Pythagarus, but leaves Ionia for Southern Italy, (to a town named ''Elea''). Xenophanes was less mystical and wrote of the Pythagarus school. Xenophanes did not believe in transmigrartion of souls, or in primitive greek gods, but in a mono theism rare to greek. Xenophanes found seashells on mountain tops and reasoned that earth changed over time, so that mountains must have been under sea and then rose, therefore Xenophanes is the first human in history to make a contribution to the science of Geology. Not until Hutton were any other contributions to Geology made. Our knowledge of his views comes from his surviving poetry, all of which are fragments passed down as quotations by later Greek writers. His poetry criticized and satirized a wide range of ideas, including the belief in the pantheon of human-like gods and the Greek people's continued support of athleticism. Xenophanes rejected the idea that the gods resembled humans in form. One famous passage ridiculed the idea by claiming that, if oxen were able to imagine gods, then those gods would be in the image of oxen. Because of his development of the concept of a ''one god greatest among gods and men'' that is abstract, universal, unchanging, immobile and always present, Xenophanes is often seen as one of the first monotheists.
2,536 YBN [530 BCE]	797) Eupalinus, Eupalinus of Megara (20 mi west of athens), a Greek architect, constructed for the tyrant Polycrates of Samos a tunnel to bring water to the city, passing the tunnel through a hill for half a mile, starting at both ends, meeting at the center and unaligned by only a few inches.
	798) Theodorus of Samos is a Greek sculptor and architect who, along with his father Rhoecus, also a sculptor in Samos, is often credited with the invention of ore smelting and, according to Pausanias, the craft of casting. He is also credited with inventing a water level, a carpenter's square, and, according to Pliny, a lock and key and the turning lathe.
2,535 YBN [529 BCE]	772) Pythagoras (~560 BCE Samos-480 BCE Metapontum [Southern Italy]), is first to describe earth as a sphere, and inspires study of math, astronomy, music and gender equality, but also supports secrecy and mysticism which some claim have had a bad and long lasting effect on science. Pythagoras adapts the earth-centered crystalline sphere system of Anaxamander, but with the earth as a sphere instead of a cylinder.
2,526 YBN [520 BCE]	785) Hecataeus (Greek: Εκαταίος) (~550 BC Miletus-476 BC) of Miletus is a Greek historian, native of Miletus from a wealthy family. Hecataeus continued the tradition of Thales, traveled through the Persian empire, and made a book on Egypt and Asia that has never been found. In Egypt, Egyptian humans showed Hecataeus records going back hundreds of generations. Hecataeus continued the work of anaximander in trying to map the entire earth. Hecataeus rationalised history and geography, writing the first account of history that did not accept gods and myths at face value. Hecataeus had a skeptical and scornful view of myths. Hecataeus and his books will undoubtably become the inspiration for the later historian Herodotus.
2,516 YBN [510 BCE]	786) Heraclitus (~540 BC Ephesus 30 mi north of Miletus, ~540 bc - ~475 bc) disagrees with Thales, Anaximander, and Pythagorus about the nature of the ultimate substance, thinking fire to be a fundamental element of the universe. Heraclitus claims that the nature of everything is change itself. A typically pessimistic view led to Herkleitos being called the ''weeping philosopher''. Only fragments of text by Heraclitus have been found.
	787) Parmenides (~540 BC Elea (now Velia), Italy - ??) a student of Ameinias, and pre-Socratic philosopher, follows in the tradition of the Ionian exiled Pythagorus and Xenophanes. Parmenides opposed the view of Heraclitus, claiming that one object can not turn in to other object fundamentally different. Parmenides argued that creation (something from nothing) and destruction (nothing from something) is impossible. Parmenides chose reason over senses, feeling senses to be untrustworthy. Parmenides founds school in Elea, the ''Eliatic School'' based on this philosophy of reason over senses. Zeno was the most recognized person educated in the school. Zeno, will use distrust of senses to describe a set of paradoxes.
2,496 YBN [490 BCE]	789) Hanno (~530 BC Carthage near now called Tunis - ???), Cathaginian (A branch of the Phoenicians) Navigator, sails 60 ships with 3000 people, down the coast of Africa in order to start new settlements. Much of what is learned about Hanno is from an 18 sentence travel-record, or ''Periplus'' of this journey, from Herodotus, and Pliny the Elder. Herodotus will express doubts about the accuracy of Hanno's story, because of a report that in the far south the sun at noon was in the nothern half of the sky, which Herodotus will think is impossible, but is in fact true for the southern hemisphere of earth. This is strong evidence, taken together with the Periplus of Hanno's journey that Hanno is the first human to sail over the equator into the Southern Hemisphere.
2,476 YBN [470 BCE]	840) Alcmaeon (oLKmEoN) (᾿Αλκμαίων) (~500 BC Croton, Italy - ???) is first to theorize that the brain is the center of wisdom, and emotions. Alcmaeon is the first human known to dissect the bodies of humans and other species. [check in ] Alcmaeon records the existence of the optic nerve and the tube connecting the ear and mouth, and distinguishes arteries from veins. Both Democritus and Hippocrates (and Plato and Philolaus ) will accept the idea that the brain is the center of wisdom and emotions, two generations later. This view of the brain as the center of emotions will not be accepted by Aristotle, who thinks the heart is the center of wisdom and emotions. This more accurate view of the brain as the center of wisdom and emotions was not popular for thousands of years, and many people even now still believe that the heart is the center of emotions, evidence of this is in the common expression ''to feel something in your heart''. These two tubes are now called the ''Eustachian tubes'', named after Eustachio, who will describe these tubes again 2000 years later. Alcmaeon lived in Croton during the height of Pythagarus' influence. There is evidence that Alcmaeon was not Pythagorean (for example, Aristotle writes a book on the Pythagoreans and a separate book on Alcmaeon), but the possibility exists that Alcmaeon was Pythagorean. Alcmaeon thought the human body was a microcosm, reflecting the macrocosm (universe). Alcmaeon distinguished arteries from veins, but did not recognize these as blood vessels, because veins and arteries are empty in dead people. [t: check, I find this hard to believe, where would the blood go?] Alcmaeon wrote at least one book, or which only fragments remain.
2,474 YBN [468 BCE]	837) A stony meteroite falls on the north shore of the Aegean. This may lead Anaxagarus to think planets, stars, and earth are made of the same materials, and that the sun was a flaming stone.
2,470 YBN [464 BCE]	836) Anaxagoras (~500 BC Clazomenae/Klazomenai 75 mi north of Miletus - ~428 BC Lampsacus now Lapseki Turkey) introduces Ionian science of Thales to Athens, saying that the universe was not made by a diety, but through the action of infinite ''seeds'', which will later develop into atomic theory under Leucippos. Anaxagoras accurately explains the phases of the earth moon, and both eclipses of moon and sun in terms of their movements. Anaxagoras says that the sun is a red hot stone and the moon a real place like the earth, not gods as is the prevailing belief. moves to Athens from Asia Minor (Turkey). Anaxagoras brought philosophy and the love of scientific inquiry from Ionia (and Thales) to Athens (as Pythagorus had to Italy). Anaxagoras was a rationalist (not a mystic like Pythagoras). Anaxagarus explained accurately the phases of the earth moon, and both eclipses of moon and sun in terms of their movements. Anaxagoras supports the opinion that the universe originated not by a diety but through the action of abstract mind on an infinite number of ''seeds'', seeds that were a form of atoms simultaneusly thought of by Leucippos. According to Anaxagoras ''heavenly'' bodies - planets, stars were brought in to existence by the same processes that formed the earth and that these bodies are made of the same materials. Anaxagoras says that the sun is a red hot stone and the moon a real place like the earth. Pericles learned to love and admire him, and the poet Euripides derived from him an enthusiasm for science and humanity. Some authorities assert that even Socrates was among his disciples. Anaxagoras thinks the sun to be an incandescent rock the size of the Peloponnesus (about the size of Massachussetts), and thinks the moon is like earth and might be inhabited. Anaxagoras teaches in Athens for 30 years, and the school formed by Anaxagoras starts the scholoarly tradition that lasts for 1000 years.
2,466 YBN [460 BCE]	835) Zeno (490? BCE, Elea now Velia south Italy - 430? BCE), is chief of ''Eliatic School'' (means ''from Elea'') in Athens and may have taught Pericles. The Eliatic humans teach the terribly false theory that senses are not useful for finding truth. Zeno made 4 paradoxes that were supposed to disprove the possiblity of motion as sensed. The most popular of these paradoxes is ''Achilles and the tortoise'', which is explained for example, by saying, if Achilles moves 10 times the speed of a tortoise, and the tortoise is 10 meters in front, Achilles will never catch the tortoise because when Achilles goes 10 meters, the tortoise has already moved 1 meter, by the time Achilles moves that 1 meter, the tortoise has moved 1/10 meter. This was supposed to be a paradox because humans usually view a fast object passing a slow object, so the human senses must be false. Although based on errors, the paradoxes will stimulate humans like Aristotle, who, for example, will give arguments against the paradoxes. Zeno bases these paradoxes on the idea that space and time are infinitely divisible, and this encourages laters humans like Democritus, into searching for indivisible objects and reaching the conclusion of atoms. This view did not win popularity until 2200 years later with Dalton.
	841) Leukippos (Greek Λευκιππος ) (lEUKEPOS?) (Leucippus) (~490 BC Miletus -???) is the first person of record to support the theory that everything is composed entirely of various indestructable, indivisible elements called atoms. Leukippos represents the final part of science and logic in Asia Minor before the destruction of the coastal cities by humans from Persia. Leukippos teaches Democritos. Leukippos is the first person to say that every event has a natural cause. Leukippos is a contemporary of Zeno, Empedocles and Anaxagoras of the Ionian school of philosophy. The popularity of Leukippos will become so completely overshadowed by that of Democritus, who systematized his views on atoms, that years later Epicurus will doubt the very existence of Leukippos, according to Diogenes Laertius x. 7. However Aristotle and Theophrastus explicitly credit Leukippos with the invention of Atomism. The most famous among Leucippus' lost works were titled Megas Diakosmos (The Great Order of the Universe or The great world-system) and Peri Nou (On mind). Diogenes Laertius reports that he was a student of Parmenides' follower Zeno. Aristotle certainly ascribes the foundation of the atomist system to Leucippus. Leucippus is sometimes said to have been the author of a work called the Great World-System; one surviving quotation is said to have come from a work On Mind. A single fragment of Leucippus survives. : ''Nothing happens at random (maten), but everything from reason (ek logou) and by necessity.'' Leucippus is named by most sources as the originator of the theory that the universe consists of two different elements, which he called �the full� or �solid,� and �the empty� or �void�. Both the void and the solid atoms within it are thought to be infinite, and between them to constitute the elements of everything. Leucippus is reported to hold that the atoms are always in motion (DK 67A18). Aristotle criticizes him for not offering an account that says not only why a particular atom is moving (because it collided with another) but why there is motion at all. Because the atoms are indestructible and unchangeable, their properties presumably stay the same through all time. The argument for indivisible atoms is said to have been a response to Zeno's argument about the absurdities that follow if magnitudes are divisible to infinity.
	842) Empedocles (~490 Akragas (now Agrigento), Sicily - Mount Etna (?) ~430 bc) understands that the heart is the center of the blood vessel system. Empedocles thinks some organisms not adapted to life have died in the past. Empedocles unites the 4 elements (water, air, fire, earth) described by earlier people into a theory of the universe. Empedocles thought that objects formed and broke apart by forces similar to the human ''love'' and ''strife'', this idea will be taken by Aristotle, improved upon and remain the basis for chemistry for more than 2000 years. Empedicles gains an understanding of air by trying to fill a clepsydra (also called �water thief'', a hollow brass sphere with a long tube) by holding a thumb on the hole which then prevents water from entering the spherical container. Empedocles is actively pro-democracy where he lives in the Greek city of Akragas in Sicily, and helps to overthrow a tyranny in Akragas. When offered the job of tyrant, Empedocles refuses because he wants more time for philosophy. Empedocles is known also as a physician, as well as a philosopher and poet. Empedocles is influenced by Pythagoras, shows some amount of mysticism, does not object to being called a prophet and miracle-worker, and is thought to bring dead humans back to life. Empedocles says on one day he would be taken up to heaven and made a god, and on that day he is supposed to have jumped into the crator of Mount Etna, although some people say he died in Greece. Empedocles combined the views of the schools of Asia Minor. Thales had water, Anaximenes had air, Heraclitus had fire, and Xeonphanes had earth as the main element of the universe and Empedocles combined these elements in his theory of the universe. His philosophical and scientific theories are mentioned and discussed in several dialogues of Plato, and they figure prominently in Aristotle's writings on physics and biology and, as a result, also in the later Greek commentaries on Aristotle's works. Diogenes Laertius devotes one of his Lives of Eminent Philosophers to him (VIII, 51-77). His writings have come down to us mostly in the form of fragments preserved as quotations in the works of these and other ancient authors. Extensive fragments, some of them not previously known, were recently found preserved on a papyrus roll from Egypt in the Strasbourg University library (see Martin and Primavesi 1999). Traditionally, Empedocles' writings were held to consist of two poems, in hexameter verse, entitled ''On Nature'' and ''Purifications''.
	1037) 6 7
2,456 YBN [450 BCE]	843) Philolaus (~480 BCE Tarentum or croton - ~385 BCE), the most recognized of the Pythagorian school after Pythagoras, theorizes that the earth was not the center of the universe but moves through space. Philolaus thinks the earth, moon, the other planets and sun circle a great fire in separate spheres, and that the sun is only a reflection of this fire. This is the first recorded idea that the earth moves thru space. Philolaus is the first to print Pythagorian views and make them available to the public. Because of persecutions, Philolaus temporarily moves to Thebes (on the Greek mainland). Instead of 9 spheres Philolaus made 10 (10 was viewed as a special number, one example is that 1+2+3+4=10). This is the first recorded idea that the earth moves thru space. When Copernicus claimed that the earth and planets move circling the sun, some people labeled this ''Pythagorean heresy''. Philolaus thought that the spheres of the planets made celestial music as they turned, and this theory persisted even to the time of Kepler. Philolaus is a contemporary of Socrates. Philolaus writes at least one book, ''On Nature'', which is probably the first book to be written by a Pythagorean. Of the 20+ fragments preserved in Philolaus' name, it is generally accepted that eleven of the fragments come from his genuine book. The other fragments come from books forged in Philolaus' name at a later date. Philolaus is a precursor of Aristarchos in moving the Earth from the center of the universe to a planet. Some view this theory as an attempt to explain physical phenomena, and others view this theory as a guess, or based on mystical reasons. Philolaus' genuine book was one of the major sources for Aristotle's account of Pythagorean philosophy.
2,440 YBN [434 BCE]	839) Viewing Athens as not safe, Anaxagoras moves to Lampsacus. Meton continues astronomical research in Athens, but popular people in Athens turn from natural philosophy to moral philosophy.
2,436 YBN [430 BCE]	838) Anaxagarus is accused of impiety and atheism and brought to trial. Pericles faces people in court in defense of Anaxagoras, and Anaxagoras is freed (unlike Socrates a generation later). Anaxagoras is the first human of history to have a legal conflict with a state religion. The people in Athens cannot accept the rationalism of Anaxagoras (similar to the people of Croton to Pythagoras but with with mysticism). Anaxagoras was a friend of the most respected people in Athens, including Euripides (wrote plays), and Pericles. Some people claim that enemies of Pericles attempted to hurt Pericles through his friend Anaxagarus.
	845) Demokritos (Democritus) (Greek: Δημόκριτος) (~460 BC Abdera, thrace -~ 370 BC) in Abdera, elaborates on atomic theory of his teacher Leukippos. Demokritos thinks that the Milky Way was a vast group of tiny stars. Demokritos explains the motions of atoms as based on natural laws, not on the wants of gods or demons. Demokritos thinks that the Milky Way was a vast group of tiny stars. Aristotle, argues against this. Democritus was among the first to propose that the universe contains many worlds, some of them inhabited: [t: both ''world'' and ''universe'' translate as ''kosmos'', but perhaps ''kosmos'' is also used to refer to planets?] ''In some worlds there is no Sun and Moon, in others they are larger than in our world, and in others more numerous. In some parts there are more worlds, in others fewer (...); in some parts they are arising, in others failing. There are some worlds devoid of living creatures or plants or any moisture.'' Democritus traveled in egypt, and settled in Greece. He learned the rationist view from his teacher Leukippos of Miletus (Thales also from Miletus). Like all the early rationalist people some ideas have a modern sound. He lived in the shadow of Socrates, who rejected the universe as defined by Democritus. None of the 72 books written by Democritos has ever been found, humans only have records of Democritus from other people (often unfriendly). Widely called the ''laughing philosopher'', perhaps because he was cheerful, or because he laughed more than most people. Demokritos thinks that even the human mind and the gods (if any) were made of combinations of atoms. Each atom was different and explained the various properties of substances. Atoms of water were smooth and round so water flowed and had no shape, atoms of fire were thorny which made burns painful, atoms of earth rough and jagged so they held together to form a hard substance. Demokritos explains changes in nature and matter as the separating and joinging of atoms. These views are similar to Anaximander. One of the first mechanist people, saw universe as a mindless and determinate as a machine. the creation of the universe was the result of swirling motions set up in great numbers of atoms, forming worlds (planets?). Later people will chose to follow Socrates rather than Democritus, with the exception of Epicurus 100 years later, who will teach atomism. The atomists hold that there are smallest indivisible bodies, Demokritos called ''atoma'', which means ''cannot be divided'', from which everything else is composed, and that these move about in an infinite empty space. Democritus is said to have known Anaxagoras, and to have been forty years younger. Much of the best evidence is that reported by Aristotle, who regarded him as an important rival in natural philosophy. Aristotle wrote a monograph on Democritus, of which only a few passages quoted in other sources have survived. Democritus seems to have taken over and systematized the views of Leucippus, of whom little is known. Although it is possible to distinguish some contributions as those of Leucippus, the overwhelming majority of reports refer either to both figures, or to Democritus alone; the developed atomist system is often regarded as essentially Democritus'. Diogenes Laertius lists 70 works by Democritus on many fields, including ethics, physics, mathematics, music and cosmology. Two works, the ''Great World System'' (''Megas Diakosmos'') and the ''Little World System'' (''Micros Diakosmos''), are sometimes ascribed to Democritus, although Theophrastus reports that the former is by Leucippus.
	847) Hippocrates (460 BCE Cos - ~370 BCE Larissa (now Larisa), Thessaly) founds a school of medicine on Cos that is the most science based of the time. Hippocrates will be recognized as the father of medicine, although other people (like Alcmaeon had practiced healing and were students of the human body). 50 books, called the Hippocratic collection, are credited to him, but are more likely collected works of several generations of his school, brought together in Alexandria in 200-300 BCE. The books contain a high order of logic, careful observation, and good conduct. Disease was viewed as a physical phenomenon, not credited to arrows of Apollo, or possession by demons. For example, epilepsy, was thought to be a sacred disease, because a human appeared to be in the grip of a god or demon, but in this school epilepsy was described as being caused by natural causes and thought to be curable by physical remedies, not by exorcism. There is much uncertainty, but Hippocrates was born of a family in a hereditary guild of magicians on the Isle of Cos, described to be descended from Asklepios, the Greek god of medicine. Visited Egypt early in life, there studied medical works credited to Imhotep. Some people claim that he was a student of Democritus. Hippocrates taught in Athens (and other places), before opening his own school of health in Cos. ''desperate diseases require desperate remedies'', ''one man's meat is another man's poison'' are two quotes from this text. The people in the school taught moderation of diet, cleanliness and rest for sick or wounded (and also clenliness for physicians), that the physician should interfere as little as possible in the healing process of nature (excellent advice for the amount of info learned at that time). For the most part, disease was thought to be the result of an imbalance of the vital fluids (''humors'') of the body, an idea first advanced by Empedocles. These were listed as four: blood, phlegm, black bile and yellow bile. A statue found on Cos in 1933 is thought to be of Hippocrates.
2,416 YBN [410 BCE]	849) Meton (~440BC Athens - ???) finds that 235 lunar months (moon rotations of earth) are close to 19 earth years, so if there are 12 years of 12 lunar months, and 7 years of 13 lunar months, every 19 years the lunar calendar would match the seasons. This will come to be called the ''Metonic cycle'' (although probably recognized by astonomers in Babylonia before this time). The Greek calendar will be based on the Metonic cycle until 46 BCE when the Julian calendar will be made by Julius Caesar with the help of Sosigenes.
2,414 YBN [408 BCE]	1138) Aristophanes (Greek: Ἀριστοφάνης) (c.448 BCE � c.385 BCE) a Greek comedy playwriter, questions the idea of Gods in [cannot find play] by writing ''Shrines! Shrines! Surely you don't believe in the gods. What's your argument? Where's your proof?'' and in the comedy play ''Knights'': ''Demosthenes: Of which statue? Any statue? Do you then believe there are gods? Nicias: Certainly. Demosthenes: What proof have you?''
2,405 YBN [399 BCE]	846) Sokrates (Greek: Σωκράτης) SO-Kro-TES? (~470 BC Athens - 399 BC Athens) is sentenced to death and forced to end his own life, charged with impiety, (failure to show due piety toward the gods of Athens, ''asebia'' greek: ασέβεια) and of corrupting Athenian youth through his teachings. One major issue with Sokrates is his opinion on democracy. Plato clearly is anti-democracy, but Sokrates appears to defend Athenian democracy with his military service, is friends with a Democratic general, and accepts the democratic decision of the jury instead of chosing to escape. Another issue is Sokrates support for science. Clearly ''The Clouds'', written by Aristophanes in 423 BCE, paints Sokrates in the tradition of science and learning, and warns of the dangers of free thought. But there are clearly no recorded scientific contributions from Sokrates, and his life appears to revolve around conversation mainly centered on ethics, although Sokrates can be possibly credited with atheism. Clearly there is friction between the traditional belief in gods and the newer belief in science which is associated with logic and atheism. Anaxagoras was persecuted for atheism, in Athens, 31 years earlier, in 430 BCE. Another central issue is the conflict between the educated and the uneducated, in the case of Plato, blame is placed on Democracy for the brutality and stupidity of the majority, instead of on stupidity and lack of education itself. Isaac Asimov claims that this will have a profound effect on science, and that it is surprising that the Greek people failed in science after such an excellent start with Thales, Demokritos, Eratosthenes, Aristarchos and Archimedes. Asimov claims that there are other factors, but one cause was the popularity of the views of Socrates (Carl Sagan relates the origin of these views to Pythagorus), typing that the largest part of Greek wisdom was focused into the field of moral philosophy, while natural philosophy (now called science) became less popular.
2,404 YBN [398 BCE]	850) Archytas (greek: Αρχύτας) (428 BC - 347 BC), third most recognized Pythagorean, solves problem of ''doubling a cube''.
2,393 YBN [387 BCE]	851) Plato (Greek: Πλάτων, Pl�tōn, ''wide, broad-shouldered'') (~427BC Athens - 347 BC Athens) founds a school in western Athens on a piece of land once owned by a legendary Greek human named ''Academus'', and so this school comes to be called ''The Academy'', and this word will eventually generally apply to any school. The Academy will be a center for science and education for 900 years until 529 CE. Plato is an Athethian aristocrat (of the ruling class or nobility) whose original name is ''Aristocles'', but he gets the nick name ''Platon'' (meaning ''broad'') because of his broad shoulders. (Cicero also was a nick name). Plato is in the ''war service'' (tph military?) and is interested in politics, but rejects Athenian democracy.
2,384 YBN [378 BCE]	854) Eudoxus (Greek Εύδοξος) (~408 BC Cnidus (now Turkish coast) - ~355 bc Cnidus) is the first Greek human to realize that the year is not exactly 365 days, but 6 hours more. Egyptians were already aware of this and Eudoxus may have gotten this idea from Egypt. Eudoxus draws a map of earth better than the map of Hecataeus. Eudoxus is first greek human to try to map stars. Eudoxus divides the sky in to degrees of latitude and longitude, a system that is eventually applied to the earth. Eudoxus is at the Acadamy, and then later creates his own school in Cyzicus on Northwest coast of Turkey. Eudoxus visited Plato. Eudoxus is the first to try to save the appearances of the Plato [t Pythagorean?] theory of planets moving on spheres.
2,376 YBN [370 BCE]	883) Hiketis (c. 400 BCE � c. 335 BCE) (῾Ικέτης), and fellow Pythagorean Ekfantos (Έκφαντος) (400 BCE) are the first to theorize that the earth turns on its own axis. Herakleitos will adopt this theory.
2,372 YBN [366 BCE]	859) Aristotle (Ancient Greek: Αριστοτέλης, Aristot�lēs) (ArESTOTeLAS?) opens his own school in Athens, called the Lyceum (Λύκειον, Lykeion) (lIKEoN?). Aristotle classifies 500 species, and dissectes nearly 50, correctly classifying dolphins with species of the field, not with fish. Aristotle puts forward the first theory of gravity, claiming that heavy objects go down and incoreectly that light objects go up.[7 302] Aristotle founds school called Lyceum, because aristotle lectured in a hall near temple to Apollo Lykaios (Apollo, wolf god), also called the ''Peripatetic School'' because Aristotle some times lectured while walking through the gardens of the school. Aristotle makes an early university library of manuscripts (papyri?). Aristotle founds the science of logic. Aristotle classifies 500 species, and dissectes nearly 50. Interested in sea life, Aristotle finds that dolphins are born alive and nourished by a placenta. No fish has a placenta but mammals do, and Aristotle correctly classifies dolphins with species of the field, not with fish. Aristotle also studied viviparous sharks, born with no placenta. Aristotle notes that torpedo fish stun other fish (with electricity). Aristotle is wrong in denying gender to plants. He studies the embryo of chicken, and the stomach of a cow. He thinks incorrectly that the heart is center of life and thinks the brain is only a cooling organ for the blood. Aristotle accepts the spheres of Eudoxus and Callipus and added more spheres to make 54 spheres in total. Aristotle thinks these spheres are real where Eudoxus probably thought they were imaginary. Aristotle accepts the 4 elements of Empedocles but only on earth, and adds a 5th element of ''aether'' for the heavens. This theory of aether will continue until the Michaelson-Morley experiment proves that no aether exists 2000 years later. Aristotle agrees with Pythagoreans that that laws of the heavens and earth were separate. Aristotle thinks that heavier object fall faster than lighter objects (technically, wrong for small everyday objects near earth, but true in principle for 3 similar mass objects. A heavier object will reach a second object faster than a lighter object will when all 3 objects are similar masses, because the heavier object will pull the other mass closer faster than the lighter object. For us earth bound people, common mass objects like rocks will not be massive enough to move the earth closer to them, and so therefore reach the earth at the same time.). Aristotle rejects the atoms of Leukippos and Democritos, dooming that idea for thousands of years, although Aristotle agrees with Pythagoras that the earth is a sphere. Aristotle found the science of zoology (the study of all living objects, biology). Aristotle thinks that sound travelled as impacts in air and could not exist without air. Following Plato's example, Aristotle gives regular instruction in philosophy in a gymnasium dedicated to Apollo Lyceios, from which his school will come to be known as the Lyceum. The school is also called the Peripatetic School because Aristotle preferred to discuss problems of philosophy with his pupils while walking up and down (peripateo), the shaded walks (peripatoi) around the gymnasium. Aristotelian philosophy then depended upon the assumption that man's mind could elucidate all the laws of the universe, based on simple observation (without experimentation) through reason alone.
2,363 YBN [357 BCE]	856) Herakleitos (Heracleides) (Ηράκλειτος) (387 BCE- 312 BCE) adopts the view of two Pythagoreans, Hiketos and Ekfantos, in theorizing that the earth rotates on its own axis. Herakleitos thinks that the planets Mercury and Venus orbit the sun (although putting the earth at the center of the universe). Herakleitos speculates that the universe was infinite, each star being a world in itself, composed of an earth and other planets. Herakleitos learns in Plato's Academy. Herakleitos wrote on astronomy and geometry and thought the earth possibly rotated. Aristarchus took this idea, but the support Hipparchus gives for the earth centered theory was more popular.
2,342 YBN [336 BCE]	868) Phillip II is killed. Aristotle moves back to Athens, and Alexander III (Alexander the Great) starts to take over the Persian empire. Aristotle sends his nephew Callisthenes as historian.
2,338 YBN [332 BCE]	921) One story has Alexander planning the city with his best advisors, and laying out the city in either seeds or flower. When a large flock of birds eat the seeds, Alexander thinks this is a bad omen, but his advisors tell him that this means the city will serve many people from all over [try to find source of exact story]. This story has Alexander commanding that there be a library dedicated to the Muses built in Alexandria.
2,331 YBN [325 BCE]	887) Pytheas PitEoS (Πυθέας) (380 BCE Massalia [now Marseille France]- 310) sails to Great Britain and possibly Iceland. Pytheas is the first person to explain tides as happening because of the influence of the moon, is the first person to show that the North star was not exactly at the pole and makes a small circle in a day. Pythias describes the Midnight Sun (the Sun is visible for 24 hours), the aurora and Polar ice, and is the first person to mention the name ''Britannia'' and Germanic tribes.
2,329 YBN [323 BCE]	862) After Aristotle moves to Chalcis, Aristotle choses Theofrastos (Theophrastus) (Θεόφραστος) (tEOFrASTOS?) (~372 BC Eresus, Lesbos - 287 Athens) to preside over the Peripatetic school, which he does for thirty-five years. The Lyceum maintains it's highest quality under Theophrastos. Theophrastos describes over 500 species of plants and is the founder of botony, the study of plants. Theophrastus is charged with asebeia (atheism) but acquitted by a jury in Athens.
	863) Aristotle is charged with ''impiety'' (lack of respect for gods, atheism) and leaves Athens.
	864) Callippus (Καλλιππος) KAL lEP POS? (~370 BCE Cyzicus - ~ 300 BCE) makes a more accurate measurement of the solar year, finding the measurement of Meton 100 years earlier to be 1/76 of a day too long. Kallippos constructs a a 76 year cycle of 940 months to unite the solar and lunar years. This calendar is adopted in 330 BCE and will be used by all later astronomers. Ptolemy gave us an accurate date for the beginning of this cycle in 330 BC in the Almagest saying that year 50 of the first cycle coincided with the 44th year following the death of Alexander. Callipps studies under Eudoxus and adds 8 more spheres to the 26 earth-centered spheres of Eudoxus, in order to more accurately explain the motions of the planets. The system made by Eudoxus has the Sun, Moon, Mercury, Venus and Mars each with five spheres while Jupiter and Saturn have four and the stars have one. This addition of six spheres over the system proposed by Eudoxus increases the accuracy of the theory while preserving the belief that the heavenly bodies had to possess motion based on the circle since that was the 'perfect' path. He also made careful measurements of the lengths of the seasons, finding them to be 94 days, 92 days, 89 days, and 90 days. This variation in the seasons implies a variation in the speed of the Sun, called the solar anomaly. The different length of the seasons is due to the fact that the sun is at one focus of an ellipse, which means that the earth will be on one side of the sun for more time than the other side.
	877) Ptolemy I Soter (Greek: Πτολεμαίος Σωτήρ Ptolemaios Soter, 367 BC�283 BC), a Macedonian general, becomes ruler of Egypt (323 BC�283 BC) and founder of the Ptolemaic dynasty.
2,317 YBN [311 BCE]	885) Epikouros (Επίκουρος) (Epicurus) (02/341 BCE Samos - 270 BCE Athens) founds a popular school in Athens. He argues against the existence of any god. Epikouros basis his philosophy on the principle that pleasure is good and pain is bad. This is the first school to admit females and slaves. Epikouros agrees with the atom theory of Demokritos. Eipkouros defines justice as an agreement ''neither to harm nor be harmed.'' In contrast to Aristotle, Epikouros argues that death should not be feared. Later humans will mistake the views of Epikouros to be supporting free, open and overindulgent sexuality, but he mistakenly warns against overindulgence because he believes that it often leads to pain. Epicurus thinks the highest pleasure is living moderately, behaving kindly, removing the fear of the gods, and death. Of 300 treatises (scrolls?), almost nothing has been found. Epikouros establishes the philosophy called Epicureanism. Epikouros forms ''The Garden'', named for the garden he owns about halfway between the Stoa and the Academy. This original school had only a few members and was based in Epicurus' home and garden. An inscription on the gate of the garden reads: ''Stranger, here you will do well to delay; here our highest good is pleasure.'' The school's popularity grows and it will became, along with Stoicism and Skepticism, one of the three dominant schools of Hellenistic Philosophy, lasting strongly through the later Roman Empire.
2,316 YBN [310 BCE]	869) Kidinnu (340 BCE Babylonia - ???), head of the Astronomical school in Sippar (Babylonia), works out the precession of equinoxes (the axis of the Earth slowly changes direction over many years ).
2,311 YBN [305 BCE]	884) Herofilos (Ηροφιλος) (Herophilus) (335 BCE Chalcedon [now Kadikoy, Istanbul Turkey] - 280 BCE) is the first human to distinguish nerves from blood vessels, in addition to motor nerves from sensory nerves. Herofilos is the first to describe the liver and spleen, to describe and name the retina of the eye, to name the first section of the small intestine ''the duodenum'', to describe ovaries, the tubes leading to the ovaries from the uterus, and names the prostate gland. Herofilos is the first human to note that arteries carry blood, not air as previously believed, a recognizes that the heart pumps blood through the blood vessels. Herofilos is first to distinguish between cerebrum and cerebellum. Herofilos notes that arteries, not like veins, pulsate, and times the pulsations with a water clock, but does not make connection between artery pulse and heart pulse. Herofilos is the first human to think wrongly think that blood letting has value, and this focus on bleeding will have a bad effect on healing for 2000 years. Erasistratus will carry on Herofilos' work, but after Erasistratus the Alexandria school of anatomy declined. Like Alkmeon, Herophilus also identifies the brain as the center of widom and emotion, not the heart. Together with Erasistratus he founders of the great medical school of Alexandria. Herofilos makes many contributions to anatomy. Herophilus performs up to 600 dissections in public. Herophilos divides nerves into sensory (get sense information) and motor (those responsible for motion). Herophilus' chief work was in anatomy, on which he composed several treatises, including one On Dissections in several books, and where a number of the terms he coined passed, either directly or via their Latin translations, into anatomical vocabulary. None of Herofilos' works have been found yet, but will be much quoted by Galen in the 2nd century AD. Later medical authors, Celsus, Rufus, Soranus and Galen, will quote and comment on their predecessors, often at considerable length. Before Herofilos and Erasistratos, such dissections as had been carried out were all performed on animals. Herofilos or Erasistratos starts the school of health (traditionally called medicine) in Alexandria, and this school will last at least until Galen in the second century CE.
2,306 YBN [300 BCE]	927) Ptolemy I encourages Hekataeos (Greek: Εκαταίος) of Abdura (Άβδηρα) (340-280 BCE) (not to be confused with other historian Hekataeos of Miletus 200 years earlier) to live in Egypt and write a new Aegyptiaca (history of egypt), which has not yet been found, but large parts of this work will be found in the writing of Diordorus. Hecataeus compares Egyptian Gods to Greek Gods, equating Dionysius to Osirius, Demeter to Isis, Apollo to Horus, Zeus to Ammon, Hermes to Thoth, Hephaestus to Ptah, Pan to Min, even the 9 muses to Osiris' nine maidens.
2,303 YBN [297 BCE]	902) Ptolemy I Soter (Πτολεμαίου Σωτήρα) starts construction of the Soma, in Alexandria, a mausoleum where Alexander and subsequent kings will be stored after death, the famous Lighthouse of Pharos, the research center known as the Mouseion (a temple to the Muses, a ''Mousaeion'' (Μουσείον also Μουσείου, Museum: in actuality a University and Library ) and the Royal Library (which may have been a separate building near the Mousaeion or may have been inside the Mousaeion), in the Royal Palaces area. The Mousaeion will house the smartest scientists of this time. This research center will also include a zoo. Some of these monuments will take more time to build than 2 decades and will be completed under the reign of Ptolemy II.
2,301 YBN [295 BCE]	878) Euclid (Eukleidis) (Greek: Εὐκλείδης) YUKlEDES? (325 BCE - 265 BCE), in Alexandria, makes a scroll called ''Elements'' which is a compilation of all the mathematical knowledge known up to then, and will be one of the most successful mathmatical texts in the history of earth. Euclid proves that the number of primes is infinite, that the square root of 2 is irrational, and shows light rays as straight lines. Eukleidos either answers Ptolemy I's invitation, or is recruited by Demetrios Falereus, and is one of the first people to work in the Mousaeion in Alexandria. He starts a school of mathematics at the Mousaeion which will last at least until the time of Pappus in the fourth century CE.[7 73] Euclid's ''Elements'' will go through more than 1000 editions after the invention of printing. ''Elements'' compiles all the accumulated wisdom since the time when Thales lived (250 years before). Euclid starts with axioms and postulates, then adds theorems. The only theorem credited to Euclid with most certainty is the proof for the Pythagorean theorem. This book has geometry, ratio, proportion, and number theory. In his ''Eudemiarz Summary'', Proclus (410-485 CE) writes about how King Ptolomy I, studying geometry, asks Euclid if there was no easier path to understanding geometry, and that Euclid replied that ''there is no royal road to geometry''. It is likely that this quote has been taken from a similar story told about Menaechmus (fl. c350 BCE) and Alexander the Great. Euclid states that the whole is equal to the sum of it's parts, and that a straight line is the shortest distance between 2 points.
2,296 YBN [290 BCE]	903) Berossos (Berossus), a Chaldean priest, writes a history of Babylonia, which in complete form has not yet been found, although secondary sources provide some information.[2 98]
2,293 YBN [287 BCE]	872) Strato becomes third director of the Lyceum after the death of Theophrastos.
2,291 YBN [285 BCE]	1028) Ktesibios (Ctesibius) (TeSiBEOS) (Greek Κτησίβιος), (fl. 285 - 222 BCE) a member of the Alexandrian Mouseion, is the first person of record to use compressed air, building a water and compressed air powered organ and catapult. Ktisibios uses compressed air to improve the water-clock, called a ''clepsydra'' which will be the most accurate method of measuring time until the pendulum clock of Huygens in the 1600s. Ktesibios uses the weight of water and compressed air to make a water organ (hydraulus) where water forces air through the organ pipes much like a flute, and makes an air-powered catapult. Around 25 BCE Vitruvius describes Ktisibios as using an early form of rack and pinion gearing in a water clock.
2,289 YBN [283 BCE]	882) Aristarchos correctly theorizes that the earth and other planets go around the sun. Aristarchus figures out that the Sun is one of the fixed stars, the closest star to the Earth. Aristarchos understands the earth rotates on it's own axis each day. Aristarchos understands that the sun is much larger than the earth. Aristarchos understands that the stars are very distant. Aristarchos calculates a close estimate for the size of the earth moon. A principle work of Aristarchos, titled ''Heliocentric system'', now lost, is considered by many of his contemporaries as ''impious'', and one contemporary writes that Aristarchos should be charged with impiety. Aged 32, Aristarchos moves from the Lyceum (Λύκειον, Lykeion) in Athens (presumably) to Alexandria where he will make his epochal theories. He adds 1/1623rd of a day to the solar year, estimated at 365 1/4 days by Callippus, and calculated the length of the Lunisolar cycle at 2434 years. Aristarchos understands that the stars show no visible parallax because they are very distant. From the shadow of the earth on the moon during an ecclipse, and using the size of earth given by Eratosthenes, Aristarchos calculates the size of the moon which is very close to the true size. From the shadow of the earth on the moon during a lunar ecclipse, Aristarchos estimates that the diameter of the Earth is 3 times the diameter of the Earth Moon. Using Eratosthenes' calculation that the Earth was 42,000 km in circumference, he concludes that the Moon is 14,000 km in circumference. This is a very close estimate since the moon has a circumference of about 10,916 km. Aristarchus argued that the Sun, Moon, and Earth form a near right triangle at the moment of first or last quarter moon. He estimated that the angle was 87�. Using correct geometry, but inaccurate observational data, Aristarchus concluded that the Sun was 20 times farther away than the Moon. The true value of this angle is close to 89� 50', and the Sun is actually about 390 times farther away. He pointed out that the Moon and Sun have nearly equal apparent angular sizes and therefore their diameters must be in proportion to their distances from Earth. He thus concluded that the Sun was 20 times larger than the Moon; which, although wrong, follows logically from his incorrect data. From this he may have concluded that a small body like the earth orbiting a large body like the sun would be more logical than the sun orbiting the earth. Aristarchos is the main supporter of the heliocentric system, as opposed to the geocentric system of Anaximander, the Pythagoreans, Philolaus, Plato and Archelaus. The erroneous earth-centered theory which will last for 1,800 years until Copernicus. Archimedes writes: ''You King Gelon are aware the 'universe' is the name given by most astronomers to the sphere the centre of which is the center of the Earth, while its radius is equal to the straight line between the center of the Sun and the center of the Earth. This is the common account as you have heard from astronomers. But Aristarchus has brought out a book consisting of certain hypotheses, wherein it appears, as a consequence of the assumptions made, that the universe is many times greater than the 'universe' just mentioned. His hypotheses are that the fixed stars and the Sun remain unmoved, that the Earth revolves about the Sun on the circumference of a circle, the Sun lying in the middle of the orbit, and that the sphere of fixed stars, situated about the same center as the Sun, is so great that the circle in which he supposes the Earth to revolve bears such a proportion to the distance of the fixed stars as the center of the sphere bears to its surface.'' So clearly Aristarchus believes the stars to be infinitely far away, and sees this as the reason why there is no visible parallax, an observed movement of the stars relative to each other as the Earth moves around the Sun. The parallax of stars can only be measured with a telescope. But the geocentric model is thought to be a simpler, better explanation for the lack of parallax. The rejection of the heliocentric view was apparently quite strong, as the following passage from Plutarch suggests (On the Apparent Face in the Orb of the Moon): ''[Cleanthes, a contemporary of Aristarchus] thought it was the duty of the Greeks to indict Aristarchus of Samos on the charge of impiety for putting in motion the Hearth [earth] of the universe, ... supposing the heavens to remain at rest and the earth to revolve in an oblique circle, while it rotates, at the same time, about its own axis.'' Cleanthes wrote a treatise �Against Aristarchus.�. Plutarch and Sextus Empiricus will both write about ''the followers of Aristarchus''.
2,286 YBN [06/10/280 BCE]	922) The Ptolemies in Egypt, Seleukids in Syria, and Attalids in Pergamon compete for scientific supremecy by establishing libraries and centers for learning in their capitals, Alexandria, Antioch, and Pergamum.
2,281 YBN [275 BCE]	888) Manetho (Manethon Μανέθων), a native egyptian historian, writes a history of Egypt in Greek.
2,280 YBN [274 BCE]	886) Erasistratos Ερασίστρατος (EroSESTrATOS?) (~304 BCE Chios [now Khios, an aegean island] - 250 BCE Samos), in Alexandria describes the brain as being divided in to a larger cerebrum and smaller cerebellum. Erasistratos accepts atom theory. He compares folds (convolutions) in the brain of humans with those of other species and decides that the complexity of folds is related to intelligence. He thinks each organ is connected to and fed by nerves, arteries and veins. Erastitratos thinks digestion is from grinding of the stomach (which is only partially true). He proposed mechanical explanations for many bodily processes. He rejects the 4 humor theory popularized by Hippokrates, but Galen will support this idea. He believed in a tripartite system of humors consisting of nervous spirit (carried by nerves), animal spirit (carried by the arteries), and blood (carried by the veins). Erasistratos was possibly a grandson of Aristotle and learned under Theophrasus in the Lyceum. After the work of Erasistratus, the use of dissection and study of anatomy declined. The humans in Egypt stop dissection in Alexandria and not until 1500 years later (late 1200s CE) with Mondino de Luzzi is dissection practiced again.
2,271 YBN [265 BCE]	931) Pliny the Elder will record in the 1st century CE that Hermippus, a student of Callimachus writes a commentary on the versus of Zoroaster now. This implies that these stories have been translated from Iranian to Greek.
2,263 YBN [257 BCE]	891) Archimedes (Greek: Αρχιμήδης ) (287 Syracuse, Sicily - 212 Syracuse, Sicily) is the first to understand density (how mass and volume are related). Archimedes makes a system that is equivalent to the exponential system to describe the amount of sand needed to fill the universe. He makes the best estimate of pi, builds a mechanical model of the universe, and a ''screw of Archimedes''. Achimedes outlines methods for calculating areas and volumes, which later will form calculus. Archimedes uses levers to lift heavy objects, for example the ''claw of Archimedes'' supposedly used to lift or turn ships over in the water. He reportedly invented an odometer during the First Punic War. He makes the ''screw of archimedes'' (although is not the first), a screw in a cylinder that when turned moves water up and is still used to move (pump) water. He makes a mechanical planetarian, not proud of his mechanical inventions (because this kind of hobby is not common for humans in philosophy) he prints only mathematical ideas. He makes the best estimate of pi by drawing polygons in a circle and describes pi as being between 223/71 and 220/70. Archimedes may have prevented one Roman attack on Syracuse by using a large array of mirrors (speculated to have been highly polished [bronze?] shields) to reflect and focus photons of light onto the attacking ships causing them to catch fire, although this has only been duplicated for closely unmoving ships. Archimedes also has been credited with improving the accuracy and range of the catapult. The Archimedes work ''The Sand Reckoner'' will be the primary source for future people knowing that Aristarchos understood that the earth and planets rotate the sun, in addition to being evidence that Archimedes and Aristarchos talk to each other. Archimedes screw devices are the precursor of the worm gear.
2,256 YBN [250 BCE]	894) Apollonios of Perga (Απολλώνιος ο Περγαίος ) (261 BCE Perga [south coast of Turkey] - 190 BCE Pergamum?) is the first to describe the ellipse, parabola, and hyperbola. Apollonius is a Greek geometer and astronomer, of the Alexandrian school. Apollonios is educated at the university in Alexandria, Apollonios may have learned from Archimedes. Like Euclid, Apollonois writes on math, makes 8 ''books'', 7 of which have been found. These writings include descriptions of the ellipse, parabola and hyperbola, 3 shapes Euclid did not describe. All of these shapes can be made by looking at a 2 dimensional piece of a cone (and are called ''conic sections''). Kepler will make use of the ellipse to describe the movement of planets. He possibly thinks planets go around the sun, and the sun goes around earth, like Tycho Brahe will years later. Late in life, Apollonius moves from Alexandria to Pergamum, a city in western Turkey (Asia Minor) that has a library second only to Alexanmdria.
2,252 YBN [246 BCE]	898) Eratosthenes of Cyrene (Kurinaios) (Eρατοσθένης ο Kυρηναίος) (276 BCE Cyrene now Shahat, on Libyan coast - 196 BCE Alexandria) is the first person to accurately calculate the size of the earth. On the day of summer solstace, the longest day of the year, the sun is directly over head in Syene (now Aswan) in southern egypt at the same time the sun, Eratosthenes measure was degrees from the [perpendicular]/zenith in Alexandria. The difference is because the surface of the earth is curved and not flat. Erastosthenes is aware that Syene and Alexandria are almost on the same line of longitude (or meridian). Eratosthene also knows the distance between Syene and Alexandria (Erastothenes hired a human to pace out the distance between Alexandria and Syene ), and used this distance and the angle of the sun to calculate the diameter of the planet earth. This result was in units of measurement of space called ''stadia''. Eratosthenes calculates a distance between Alexandria and Syene as 5,000 stadia, and calculates that the angle of the sun [t in Alexandria at noon on the longest day of the year] is 1/50th the circumference of a circle. What size the stade Eratosthenes uses is debated. One source has Eratosthenes using the Attic stade of 184.98m (606' 10'') based on 600 Attic feet of 308.3m each. This puts the circumference Eratosthenes measures at 46,245km (modern=40,000km) or has an Egyptian Royal cubit of the time as 525mm. For the most probable length of a ''stadia'' the number Eratosthenes got was 40,000 km (25,000 miles), this number is accurate (the current estimate is 40,075.02 km). This number appeared to be larger than most humans could accept, the smaller value of Poseidonius was accepted. From this large number compared to the ''known'' earth, Eratosthenes thought the various seas formed a single interconnected ocean. He teaches that Africa might be circumnavigated, and that India can be reached by sailing westwards from Spain. Eratosthenes makes the ''Sieve of Eratosthenes'', a system for determining prime numbers. Eratosthenes advised adding an extra day every 4 years to the Egyptian calendar, but this will wait for Sosigenes 150 years later to be officially done by Julius Caesar. Eratosthenes makes a map of the ''known'' earth, from the British Islands in the East to Ceylon in the West, from the Caspian Sea in the North to Ethiopia in the South. This map is better than any before. In astronomy, Eratosthenes measures the angle of the earth's axis with the plane the sun appears to move in, and gets an accurate value. This value is called the ''obliquity of ecliptic''. Eratosthenes makes a star map of 675 stars. Around 255 BCE he invents the armillary sphere, which will be widely used until the invention of the orrery by Posidonius (135-51 BCE). Eratosthenes denounces those who divide mankind into two groups, Greeks and non-Greeks, and those, like Aristotle and Isocrates who advised Alexander to view the Greeks as friends and non-Greeks as enemies. Eratosthenes praises Alexander for disregarding this attitude. Eratosthenes advocates the Stoic moral principles of virtue and vice as a criterion for the division of men. [7 111] Eratosthenes is a friend of Archimedes.
2,246 YBN [240 BCE]	889) Conon [KOnoN] (Κόνων) (circa 280 BCE Samos - circa 220 BCE Alexandria) learns from Euclid, teaches Archimedes.
	923) Ptolemy III has the Serapeion (Serapeum) (Σεραπείου SRoPAU?) built presumably to store surplus books of the Royal Library.[1 91]
2,241 YBN [235 BCE]	890) Philon (Φίλων) (Byzanteum 265-202 BCE), experimentes with air, found that air expande with heat, perhaps made air thermometer, noticed that air was consumed by a burning torch in a closed vessel.
2,236 YBN [230 BCE]	1034) The letter ''G'' is added to the Latin alphabet in Rome. Before this the letter ''C'' could be either the ''K'' or ''G'' sound, now the letter ''G'' will have the ''G'' sound and the letter ''C'' will only have the ''K'' sound. A more logical system would be to not add any letter ''G'', and to use the letter ''C'' only as ''G'', ''K'' for all ''K'' sounds, but this simple one letter equals one sound only system is not recognized. This confusion about how to pronounce the letter ''C'' will continue for thousands of years, persisting even today. Later the letter ''C'' will also take on an ''S'' and ''CH'' sound and ''G'' will take on the ''J'' sound, adding to a simple and unnecessary confusion.
2,192 YBN [186 BCE]	1117) The Su�n sh� shū (算數書) or ''Writings on Reckoning'' is the earliest know Chinese mathematical text.
2,166 YBN [160 BCE]	1029) Hipparchos (Greek Ἳππαρχος) (Nicaea [now Iznik in NW Turkey] 190 BCE - 120 BCE), astronomer in the Mouseion in Alexandria, uses a solar eclipse to determine the distance from the Earth to the Moon. Hipparchos, is the first person to make a trigonometric table, and is probably first to develop a reliable method to predict solar eclipses. Hipparchos compiles a star catalog with 850 stars and their relative brightness, and probably invents the astrolabe. Hipparchos does not use the sun-centered system of Aristarchos, but instead the mistaken earth-centered system Anaxamander and the vast majority of others chose to support. Hipparchos compares the position of the moon compared to the sun during a solar eclipse in Syene and in Alexandria to determine the distance from the Earth to the Moon. Hipparchos recognizes precession (how positions of stars appear to change over centuries) perhaps from Kidinnu of Babylonia, or from previously recorded star positions. Hipparchus wrote at least fourteen books, but only his commentary on a popular astronomical poem by Aratus has been preserved. Most of what is known about Hipparchus comes from Ptolemy's (2nd century AD) Almagest, with additional references to him by Pappus of Alexandria and Theon of Alexandria (4th century) in their commentaries on the Almagest; from Strabo's Geographia (''Geography''), and from Pliny the Elder's Naturalis historia (''Natural history'') (1st century). calculates a range of the distance of the earth moon from earth is 60.3x. worked in Rhodes, an island in SE Aegean. used aristarchus luner eclipse method (?) and also measured parallax of earth moon. Hipparchus measured distance from earth to moon to be 30 times diameter of earth. parallax of other planets can only be measured with a telescope so this distance was only distance known/learned/remembered until telescope. [1 32]
2,156 YBN [150 BCE]	1039) Seleukos (Seleucus) (Asimov: SeLYUKuS, t: SeLYUKOS) of Seleucia (on the Tigris River) (190BCE-?), agrees with the sun-centered theory of Aristarchos.[2 311][3 33] Seleukos views the universe as infinite in size.[2 88 Aetius and Heraclides of Pontus] Seleukos may have used changes in tides as evidence for a sun-centered theory.
2,146 YBN [140 BCE]	1070) Earliest paper artifact (although without writing) is made of hemp fibers and comes from a tomb in China.
2,111 YBN [01/01/105 BCE]	1042) Poseidonios (Poseidonius) (Greek: Ποσειδώνιος) (POSiDOnEuS) (135 BCE Apamea, Syria - 50 BCE) calculates the largest and most accurate size for the sun, even larger than Aristarchos' calculation. Ptolemy will accept Poseidonios' inaccurate smaller estimate for the size of the earth, and reject the correct estimate of Eratosthenes, and this inaccurate value will last for 1500 years.[1 34] Poseidonios forms a school in Rhodes.
2,081 YBN [75 BCE]	1116) The first use of negative numbers is in the Chinese mathematics book ''The Nine Chapters on the Mathematical Art'' (Jiu-zhang Suanshu). Negative numbers are in read and positive numbers in black.
2,062 YBN [56 BCE]	1045) Lucretius (LYUKREsEuS), Titus Lucretius Carus, Roman poet and philosopher, writes ''De Natura Rerum'' (On the Nature of things) which describes a mechanical Epikourean view of universe in a (longer than average) poem. Influenced by Democritus, Lucretius supports the idea that all things are made of atoms including souls and even gods. Like Epikouros, Lucretius thinks that the Gods are not concerned with the lives of humans, and death is not to be feared. In addition Lucretius thinks that there is no after life, only peaceful nothingness. Lucretius is the first to divide human history in to the stone age, bronze age, and iron age. Lucretius is the boldest person of this time to speak out against religion, superstition and mysticism. [1 34]
2,054 YBN [48 BCE]	956) A fire set by soldiers for Julius Caesar may have burned only some storehouses of books, or may have partially or completely burned the Royal Library too, but in any event, the Royal Mouseion (which possibly housed the Royal Library) and Sarapeion survived undamaged.
2,046 YBN [40 BCE]	1058) Vitruvius (ViTrUVEuS) Marcus Vitruvius Pollio, Roman engineer and writer, writes a book ''De architectura'', 10 books on architecture.[1 36]
2,039 YBN [33 BCE]	1059) Strabo (STrABO), a Greek historian, geographer, and philosopher, makes 17 volumes (16 that have been found), of geography based on Eratosthenes' work and accepts Eratosthenes' estimate for the size of earth. Strabo writes a long history of Rome not yet found. Strabo recognizes that Vesuvius is a volcano (which will erupt 50 years after Strabo's death).[1 38]
1,986 YBN [20 CE]	912) Aulus Cornelius Celsus (25 BCE � 50 CE), a Roman encyclopedist, makes 8 books in Latin describing Greek learning.[1 38]
1,956 YBN [50 CE]	1078) Heron of Alexandria (Greek: Ήρων ο Αλεξανδρεύς) (c.10 CE - c.70 CE), a Greek engineer in Alexandria, makes the first recorded steam engine.[1 40] The potential of the steam engine will not be understood until the late 1600s. Heron invents an aeopile, which is a hollow metal sphere that rotates from the power of steam jets that escape through open tubes on each side of the sphere. Heron describes the lever, pulley, wheel, inclined plane, screw, and wedge. Understands and uses syphons, syringes and gears. Hero uses gears to change the wheel rotations of a chariot to the rotations of a pointer that indicate the number of wheel rotations, which is the first odometer (meter that indicates distance traveled). Hero writes a book on air, which shows that air is a substance and will not enter a container already filled with air, unless air is allowed to escape and be replaced. Hero reasons that because air can be compressed, air must be made of particles separated by space. Hero made a ''book'' on mirrors and on light.[1 40] Hero describes a generalized version of the law of levers by Archimedes.[1 40] Hero was either the son or pupil of Ctesibius. Hero's inventions recorded in his work ''Pneumatics'' are mostly frivolous, many connected to religious ceremonies in order to deceive worshippers with what appear to be supernatural events. Among Hero many inventions are: a mechanical singing bird, a device that opens a temple door when a fire is lit on an alter, a device that emits a small jet of steam which supports a small sphere, a trumpet sounded by compressed air, a syringe, an alter organ blown by a windmill. Hero invents a steam boiler, which forces a hot air blast to be driven into a pipe, by pouring cold water into the boiler. This is the principle behind the ''Roman bath'' introduced around the same time, and is also the principle behind ''central heating'' still in use today. It is almost certain that Hero taught at the Museum which included the famous Library of Alexandria, because most of his writings appear as lecture notes for courses in mathematics, mechanics, physics and pneumatics. Hero probably agreed with the Atomists, accepting the theory of atoms as the most accurate.[needs citation: ancient biography of Heron?]
1,929 YBN [77 CE]	1083) Pliny the Elder, (''Gaius Plinius Cecilius Secundus'') (PlinE) (23 CE Novum Comum (now Como), Italy - August 24, 79 CE near Mount Vesuvius, Italy) completes his major work titled ''Natural History'' in 37 volumes.[1 40] ''Natural History'' is made from copying text of 500 other earlier people and contains astronomy, geology and zoology. Pliny shows wisdom in rejecting the idea of immortality. In addition to ''Natural History'', Pliny writes a ''History of his Times'' in thirty-one books, which has yet to be found.
1,926 YBN [80 CE]	1077) Pedanius Dioscorides (DEOSKORiDEZ), Greek physician, pharmacologist and botanist who practises in Rome during the reign of Nero writes ''De Materia Medica'' in 5 books. ''De Materia Medica'' is the first encyclopedia of medical plants and drugs, and describes 600 plants almost 1000 drugs.[1 40]
1,901 YBN [105 CE]	1086) Tsai Lun (TSI lUN) (c.50 CE Kueiyang, Kweichow - c.118 CE) is thought by many to have invented paper from matter like tree bark, hemp, silk and fishing net,[1 42] but artifacts of paper have been found that date to before Lun by more than 100 years.
	1087) Ptolemy, (ToLomE), Claudius Ptolemaeus, (Greek: Κλαύδιος Πτολεμαῖος), (c.90 � c.168), a Greek-speaking Astronomer, Geographer and Astrologer, in the Museum in Alexandria, writes an astronomy book, called by later people ''Almagest'' (The Greatest), in which Ptolemy names the 48 constellations still used today, and also includes a star catalog (star names and locations) based on the work of Hipparchus. Sadly Ptolemy supports the erroneous earth-centered theory and this theory will persist until Copernicus in the 1500s. Ptolemy writes a book on optics that describes refraction, reflection and color of light, and a book on geography.[1 42]
1,886 YBN [120 CE]	970) Claudius Ptolemaeus (Klaudios Ptolemaios) (Greek: Κλαύδιος Πτολεμαῖος; c.90 � c.168 CE) (Ptolemy, an astronomer, no known relation to Ptolemy royal family) writes a 13-volume ''The Great Treatise'', later named ''Almagest'', systematizes Alexandrian knowledge of astronomy and catalogs a thousand stars. Ptolemy creates an elegant mathematics of epicycles to explain the apparent motions of the stars and planets based on the incorrect geocentric cosmology derived from the texts of Aristotle. This work will be influential in Europe until the 16th century.
1,844 YBN [162 CE]	971) Galen (Greek: Γαληνός Galinos, Latin: Claudius Galenus of Pergamum) (129-200 CE), is a Greek physician. Sadly and shockingly, Galen's views will dominate the science of health in Europe for more than one thousand years. Galen is the first to understand that blood flows through veins, and is first to study nerve function. Galen is the first to identify many muscles and to decribe the movement of urine through ureters to the bladder.[1 43]
1,828 YBN [178 CE]	1030) Celsus (KeLSuS) writes ''The True Word'' against the Christian religion.
1,744 YBN [262 CE]	1031) Porfurios (Porphyry) (c.232�c. 304 AD) (Greek: Πορφυρίου) writes ''Adversus Christianos'' (Against the Christians) in 15 books, of which only fragments remain. Porfurios also advocates rights for the other species.
1,734 YBN [272 CE]	985) After the occupation of Alexandria by Zenobia, Queen of Palmyra, Emperor Aurelian attacks in the royal quarter result in so much destruction that members of the Mouseion either flee the country or take refuge in the Serapeum.[2 158] Ammianus Marcellinus records: ''But Alexandria itself was extended, not gradually, like other cities, but at its very beginning, to great dimensions, and for a long time was exhausted with internal disputes, until finally, after many years, when Aurelian was emperor, the civic quarrels escalated into deadly strife. Its walls were torn down and it lost the greater part of the area which was called the Brucheion, and which had long been the dwelling place of its most distinguished men.''[1 73] Possibly scrolls are transfered to the Serapeum, Kaisareion or Claudianum annexes. Epiphanius will write about the Brucheion a few after Ammianus, that where the library had once been, ''there is now a desert''[4 195, Patrologia Graeca, 43, 252]
1,656 YBN [350 CE]	1133) The first use of a lodestone as a direction finder is in the Chinese book ''Book of the Devil Valley Master''.
	1134) The first use of a lodestone as a direction finder is in the Chinese book ''Book of the Devil Valley Master''.
1,644 YBN [362 CE]	1032) Flavius Claudius lulianus, Julian (the Apostate), (Greek: Ιουλιανός o Παραβάτης) (331�June 26, 363) issues a ''tolerance edict'' which reopens the Pagan temples, and calls back exiled Christian bishops. Julian writes ''Against the Galileans'' which has only been preserved from the writings of Cyril of Alexandria, in his rebuttal ''Against Julian''.
1,615 YBN [391 CE]	1003) The library in the Temple to Serapis (the Serapeum) in Alexandria is violently destroyed by Christian people and the temple is converted to a church. [summarize quotes from historians] The Serapeum is an acropolis with a central temple building in the center and other buildings surrounding the border of the acropolis.[19 416] Alfred Butler relates that there were 2 chambers set apart for the library, both within the temple, concluding: ''...if the Library was part of the temple building, and if the temple building was utterly destroyed, how can it be argued that the Library did not perish? The destruction of the temple was complete: it was thrown down to the foundations. Eunapius says that 'they wrought havoc with the Serapeum and made war on its statues....The foundations alone were not removed owing to the difficulty in moving such huge blocks of stone.' Theodoret, speaking of the same events, says, 'The sanctuaries of the idols were uprooted from their foundations.' Socrates says that the Emperor's order was for the demolition of all the heathen temples in Alexandria, and that 'Theophilus threw down the temple of Serapis': and again, 'The temples were overthrown, and the bronze statues melted down to make domestic vessels.' The same writer records the discovery of stones with hieroglyphic inscriptions during the demolistion of the temple of Serapis: and similar language is used by Sozomen, who describes the Christians as having uninterruptedly occupied the Serapeum from its capture by Theophilus to his own time....Rufinus...speaks of the exterior range of buildings round the edge of the plateau as practically uninjured, though void of its former pagan occupiers: but he makes it clear, that while this outer range remained, with its lecure rooms and dwelling-rooms, not only the great temple of Serapis, but the colonnades about it, had been levelled to the ground.''. Much of the Serapeum lasts as late as the 12th century.[19 418]
1,597 YBN [409 CE]	998) Synesios (Synesius) (c370-413 CE), who studies under Hypatia, describes the pictures of philosophers in the Mouseion.[1 159] There is no later reference to the Mouseion's existence in the fifth century.[1 159] This is evidence that the Mouseion survived intact after the destruction of the Sarapeion in 391. Since Synesios is thought to have died around 414, and there are no other references after Synesios, it is possible that the Mouseion was destroyed a short time before or after the murder of Hypatia.
1,591 YBN [03/??/415 CE]	1009) Hypatia (Greek: Υπατία and Ὑπατίας) (c360 - 415), a popular female philosopher, mathematician and astronomer in Alexandria is murdered by Christian people. Many people site this as the end of ancient science.[34 15] Clearly, the seed of science survived, as science grows now, in the time we live in.
1,590 YBN [416 CE]	1011) The Museum in Alexandria is permanently destroyed by Christian people. Paulus Orosius describes the temples in Alexandria as having empty bookshelves, the contents emptied ''by men of our time''. Adding this together with the Suda reference to Theon being a member, and the last reference to the Mouseion from Synesios in 409 with no mention of any destruction before his death in 414, and no mention of any public library in Alexandria by people writing in the 5th and 6th century, it appears probable that the Mouseion (including any remaining library) may have been completely and permanently destroyed in 415 or 416.
1,558 YBN [448 CE]	1043) Theodosius II (April, 401 - July 28, 450), Eastern Roman Emperor (408-450) orders all non-christian books burned. In fighting the ancient Hellenic tradition, or ''Paganism'' as it would be later called, the Christian people destroy much of the science learned and recorded in books stored in temples to the traditional Greek Gods.
1,501 YBN [499 CE]	1309) Although debated, Aryabhata in India describes a sun-centered planetary model with the earth turning on its own axis, and planets following elliptical orbits in his book ''Aryabhatiya''.
1,477 YBN [529 CE]	1014) Roman Emperor Justinian closes the Academy in Athens. The head of the Academy, Damascus and 6 other philosophers seek asylum in Persia.[1 186] Justinian also decrees that all anti-Christian books are to be burned in this year [exact date].[4 316] None of the 'True Doctrine'' of Kelsos in the second century, the 15 books of Porfurios' ''Against the Christians'' in the third century, and Julian's ''Against the Galileans'' of the fourth century have ever been found, however some of their writing remains in rebuttles by Christian writers, for example Origen's ''Against Kelsos'' quotes Kelsos, Macarius Magnes may possibly preserve some of Porfurios' writing for which even 3 major Christian rebuttles have never been found, and Kurillos (Cyril) of Alexandria's ''Pro Christiana Religione'' reveals some of Julian's writings.[4 317]
1,378 YBN [628 CE]	1115) Brahmagupta (c.598 CE - c.668 CE) is the first person recorded to use the number zero.
1,366 YBN [640 CE]	1120) Theophanes records that Greek fire was invented around 670 in Constantinople by Kallinikos (Callinicus), an architect from Heliopolis in Syria (now Baalbek, Lebanon). This is the first reported use of a flame throwing weapon.
1,306 YBN [700 CE]	1121) Earliest mechanical clock in China.
1,302 YBN [704 CE]	1073) Oldest wood block print, a Buddhist text on a Mulberry paper scroll, from Bulguksa, South Korea. Stamps used as seals, a form of block printing was invented before this in China. Initially, an entire page would be carved on the wood block, later movable wood blocks will be used.
1,256 YBN [01/01/751 CE]	1253) Abu Musa Jabir ibn Hayyan (Arabic: جابر بن حيان) (c.721�c.815), with Latinised name Geber, is the first of the important Arab alchemists and introduces the experimental method into alchemy. Jabir is credited with being the first to prepare and identify sulfuric and other acids.
1,245 YBN [761 CE]	1122) Abu Musa Jabir ibn Hayyan (Arabic: جابر بن حیان) (c.721�c.815), known also by his Latinised name Geber, is a prominent Islamic alchemist, pharmacist, philosopher, astronomer, and physicist.
1,226 YBN [01/01/781 CE]	1254) Flaccus Albinus Alcuinus (Alcuin) (oLKWiN) (c.732�May 19, 804) a scholar, ecclesiastic, poet and teacher from York, England, accepts an invitation from Charlesmagne to be head of education for Charlemagne's kingdom which is most of Western Europe. In the Palace School of Charlemagne, Alcuin will revolutionize the educational standards of the Palace School, introducing Charlemagne to the liberal arts and creates an atmosphere of scholarship and learning. In Aachen, Alcuin designs a method of writing �Carolingian minuscule� to fit as much text on the expensive parchment. This symbol set is the ancestor of lower-case letters. All writing before this is done in capital (or majuscule) letters. In my opinion, lower case has complicated language, and people should use a one letter for one sound phonetic alphabet for all languages.
1,211 YBN [01/01/796 CE]	1255) Alcuin establishes a school in Tours where scribes are trained to carefully copy manuscripts. The new Carolingian miniscule alphabet letters created by Alcuin will spread from text copied here and ultimately develop into the miniscule (or lower case) letters used today (although I think a one letter one sound phonetic alphabet for all languages will ultimately be most popular if not completely replaced by recorded video and audio).
1,185 YBN [815 CE]	1021) Caliph al-Mamun[5 69][6 166] founds the ''Bayt al-Hikma'' (House of Wisdom) in Baghdad, Iraq. (Some people argue that al-Mamun's father al-Rashid founded the Bayt al-Hikma). A library and observatory are joined to this house. In the House of Wisdom, many works will be translated from Greek, Persian and Indian into Arabic. Many original works will be created here too. The House of Wisdom recruits and supports the most talented scholars.[4 181]
1,170 YBN [830 CE]	1257) Al-Khwārizmī (Arabic: محمد بن موسى الخوارزمي‎) (oLKWoriZmE), as a scholar in the House of Wisdom in Baghdad, translates and extends the work of Diofantos in �Ilm al-jabr wa'l muqabalah'' (the science of transposition and cancellation). ''Al-jabr'' translates into Latin as algebra. The symbols 1 through 9, the Indian numerals will be transmitted to Europe from Fibonacci's translation of this work. These numerals are easier to use than Roman numerals and will replace the Roman numerals.
	1297) Al-Khwārizmī (Arabic: محمد بن موسى الخوارزمي‎) (oLKWoriZmE) translates and extends the work of Diofantos in �Ilm al-jabr wa'l muqabalah'' (the science of transposition and cancellation). ''Al=jabr'' translates into latin as algebra. The symbols 1 through 9, the hindu numerals will be transmitted to Europe from Fibonacci's translation of this work. These numerals are easier to use than Roman numerals and will replace the Roman numerals.
1,156 YBN [850 CE]	1144) Earliest record of gunpowder in China.
1,102 YBN [898 CE]	1305) Al-Battani, an Arab astronomer, refines the length of the year to 365 days, 5 hours, 46 minutes and 24 seconds, the most accurate result for the length of the year up to this time, and this value will be used 700 years later in the Gregorian reform of the Julian Calendar.
1,095 YBN [905 CE]	1303) Al-Razi (full name Abū Bakr Muhammad ibn Zakarīya al-Rāzi Latin: Rhazes), a Persian physician and chemist, is the first to prepare ''plaster of paris'' and describes how it can be used to hold broken bones in place, to identify and distinguish between smallpox and measles, is the first of record to divide all substances into animal, vegtable and mineral, accepts the atom theory, dismisses miracles and mysticism, thinks religion harmful and the cause of hatred and wars.
1,031 YBN [975 CE]	1022) The ''Suda'', one of the first encyclopedias is compiled, credited to a person named Suidas.[1 70]
1,024 YBN [976 CE]	1308) Ibn al-Haytham (Full Name: Abu 'Ali al-Hasan ibn al-Haytham) (Arabic: أبو علي الحسن بن الحسن بن الهيثم) (Latinized: Alhazen (oLHoZeN)) (CE c965-1039), builds the first recorded pin-hole camera (camera obscura), and is the first Arab astronomer of record to support a sun centered theory.
987 YBN [1013 CE]	1409) Al-Biruni (full name: Abu Rayhan Muhammad ibn Ahmad al-Biruni) (CE 973-c1051), a Persian scholar, writes that astronomic data can also be explained by supposing that the earth turns daily on its axis and annually around the sun, and notes ''the attraction of all things towards the centre of the earth''.
965 YBN [1041 CE]	1124) ''Movable type'' printing, where individual blocks can be put together to form a text, is invented in China.
932 YBN [1068 CE]	1312) Al-Zarqali (In Arabic أبو أسحاق ابراهيم بن يحيى الزرقالي ),(full name: Abu Ishaq Ibrahim ibn Yahya Al-Zarqali) (Latin: Arzachel) (Spanish and Italian: Azarquiel), (1028�1087 CE), although debated, supports the sun-centered theory revived by al-Haytham[5 p5] and improves on this model by having the planets move in elliptical orbits[2*][5 p5] around the Sun at one focus of the ellipse.
874 YBN [1132 CE]	1146) Gunpowder is first used as a propellant. This is done in China and is recorded in experiments with mortars made of bamboo tubes. This is the first cannon and gun.
850 YBN [1150 CE]	1310) Bhaskara (1114�1185) expands on Aryabhata's heliocentric model in his astronomical treatise ''Siddhanta-Shiromani''.
822 YBN [11/??/1184 CE]	1153) The Inquisition starts when Pope Lucius III holds a synod at Verona, Italy, creating the shockingly brutal law that burning is to be the official punishment for heresy.
792 YBN [1208 CE]	1392) Robert Grosseteste (GrOSTeST), (CE c1175-1253), English scholar and teacher of Roger Bacon, is the first person to write, in his scientific treatise ''De Luce'' (Concerning light), that light is the basis of all matter (although Grosseteste does not explicitly describe light as being made of particles he does mention atomic theory). This theory will still not be publicly recognized as true by the majority of people 750 years later today. Possibly this is just an unfounded guess, and/or an extension of the biblical text describing a god commanding ''Let there by light''.
638 YBN [1368 CE]	1167) The earliest evidence [what it is I don't yet know] of the bamboo gun being replaced with bronze, which makes this the first metal gun and cannon, known as the Huochong, more reliable and powerful than the bamboo gun.
96 YBN [10/24/1910 CE]	657) The images a human sees and thinks are recorded using photons emitted from the human head by Michael Pupin at Columbia University. The exact date, time, location, invention, and even inventor are not clear because of the secrecy that still surrounds this technology.
93 YBN [1913 CE]	656) The sounds a human thinks are recorded using photons emitted from the human head by Michael Pupin at Columbia University. The exact date, time, location, invention, and even inventor are not clear because of the secrecy that still surrounds this technology.
92 YBN [1914 CE]	658) Images and sounds are sent to a human brain for the first time, using photons, presumably by Michael Pupin at Columbia University. The exact date, time, location, invention, and even inventor are not clear because of the secrecy that still surrounds this technology.
37 YBN [07/21/1969 CE]	655) First human walks on the moon.
0 YAN [01/01/0 CE]	1139) The Council of Ephesus sentences Porfurios' (and other) books against Christianity to be burned (but does not mention the emperor Julian's anti-christian writings).[1 316]
FUTURE
9 YAN [2015 CE]	790) Humans walk around with walking robot assistants.
14 YAN [2020 CE]	775) All people in advanced nations have at least a 500kb/s Internet connection.
24 YAN [2030 CE]	791) Walking robots start replacing humans in most low-skill jobs (fast-food, fruit and vegtable picking, etc)
34 YAN [2040 CE]	793) Helicopter-cars form a second line of traffic above the street level paved roads. Heli-cars are popular alternative to ground cars because of improvements to safety, for speed because street-level roads are overcrowded, and for only a little more cost. These cars are basically low flying, low-noise helicopters with ground driving abilities built in. These cars are required to travel over the already exiting roads because of sound level. These vehicles may have 3 propellers (or perhaps 1 propeller and 2 air thrusters) to allow driving more like a car without tilting.
44 YAN [2050 CE]	792) Walking robots have completely replaced humans in most low-skill jobs (fast-food, fruit and vegtable picking, etc)
94 YAN [2100 CE]	680) The majority of the humans on earth are aware that thought can be seen and heard, almost 200 years after its invention. This includes the vast majority seeing clear proof of this technology, and understand the history starting in 1910.
	794) 100 ships with humans orbit earth.
144 YAN [2150 CE]	659) First major nation to be fully democratic, where the people vote directly on the laws.
194 YAN [2200 CE]	795) 1000 ships with humans orbit earth.
269 YAN [2275 CE]	661) The majority of humans in developed nations are not religious. These people do not practice any religion, but may still believe in a god or gods.
319 YAN [2325 CE]	781) The majority of humans in developed nations do not believe in any heaven or hell.
414 YAN [2420 CE]	779) The majority of humans in developed nations do not believe in any gods.
494 YAN [2500 CE]	660) First humans permanently living in earth orbit. These may be employees of businesses that own ships that people visit, or possibly individual wealthy people that prefer to live in orbit living in ''house'' ships. Eventually, earth orbit will be filled with single family ships.
	683) Converting Venus atmophere project is started. This project removes the Carbon from the atmosphere and converts it to H2, O2. This process may be done by thousands of surface (and/or low orbit) machines working in parallel. There is so much atmosphere on Venus, that I think this process will take as many as 1000 years.
	687) Humans can convert most common atoms (Silicon, Aluminum, Iron, and Calcium) into the much more useful H2 and O2. This allows humans to live independently of earth, on planets and moons without water. This opens up large cities on the waterless planets and moons, and increases the supplies of H2 and O2 for those in between planets and in planetary or steller orbit. This is a simply process of separating atoms, the most complex process of assembling atoms from protons and neutrons, or even from photons will take more time to figure out.
	774) All humans in developed nations are not religious.
	776) All people in developed nations no longer attend religious services at least once a month.
594 YAN [2600 CE]	678) Population of humans on earth is uncomfortably large at 1 trillion (1e12) humans. Presumes no humans leave earth.
794 YAN [2800 CE]	780) All humans in developed nations do not believe in any gods. By the year 2800 CE many estimates indicate that, at current rates, all humans in developed nations will not believe in any gods, or any major religions.
	782) All humans in developed nations do not believe in any heaven or hell.
994 YAN [3000 CE]	686) Humans find a way to end aging in humans. Humans learn to change the human genome in order to grow to a certain age and maintain that age without aging any farther. This has an immediate impact on the population growth of humans in the star system, increasing the population very quickly, limited only by water and food. Humans will then grow to age 20 and stay at that age for many thousands or even millions of years, unless they are destroyed by some non-aging event, such as an accident, or violent destruction.
1,294 YAN [3300 CE]	777) The majority of humans in traditionally undeveloped nations are not religious.
1,494 YAN [3500 CE]	684) Venus atmosphere project is completed. Venus becomes second earth (although without oceans and much more efficiently organized). Once temperatures came down, more and more humans would be living on the surface of Venus, in the intermediate stage.
1,794 YAN [3800 CE]	681) Population of humans on earth moon reaches physical maximum of 250 trillion (250e12) humans.
1,894 YAN [3900 CE]	682) Population of humans on planet Mars reaches physical maximum of 500 trillion (500e12) humans.
2,294 YAN [4300 CE]	778) All humans in traditionally undeveloped nations are not religious.
2,794 YAN [4800 CE]	685) Population of planet Venus reaches physical maximum of 1 quadrillion humans (1e15).
2,994 YAN [5000 CE]	679) Population of humans on and in earth reaches a theoretical physical maximum of 333 quadrillion (333e15) humans.

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