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 µm) 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 Shröter, 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.