Timeline Of Evolution

Updated 2009-03-26 23:23

Timeline of Evolution

EventMillions of Years Ago
The Earth forms4500
unicellular organisms appear in oceans3500
seaweeds appear1200
multicellular organisms appear1000
jellyfish and molluscs appear700
fish appear490
first land plants appear430
first land animals appear400
amphibians appear380
reptiles appear350
winged insects appear300
dinosaurs appear215
mammals appear200
flowering plants appear150
extinction of dinosaurs135
apes appear40
Homo Erectus appears2


Reference: p.187 of "Usborne Essential Guides: Essential Science" by P. Wingate, C. Gifford, R. Treays. Usborne Publishing, Ltd., London, 1992. EDC Publishing, Tulsa, Oklahoma (ISBN=0-7460-1011-7).


EventMillions of Years Ago
The Earth forms4500
Oceans and continents form4000-4500
First living cells3500-3700
First photosynthetic cells3300-3500
First water-splitting photosynthesis releases O23000-3300
Aerobic respiration becomes widespread1500-2000
Start of rapid O2 accumulation
Fe2+ in oceans used up
Origin of eucaryotic cells (algae)1250-1500
Oxygen level in atmosphere stabilizes around 20%1000
First multicellular plants and animals500-750
First vertebrates300


Reference: p.385 of "Molecular Biology of the Cell" by Alberts, Bray, Lewis, Raff, Roberts, and Watson, 2nd Edition, Garland Publishing, New York, 1989 (ISBN=0-8240-3695-6).


EventMillions of Years Ago
The Earth forms4000
Only the simplest compounds of H,C,O,N exist3600
UV photo association of intermediate organic materials (amino acids, etc.)3300
Inorganic catalysts: Fe/S, Mo/S, etc.3300
Polymerization of macromolecules with natural selection (proteins, nucleic acids, enzymes, genes, hormones)3000
Colloidal coacervates associating symbiotic macromolecules with survival determined by natural selection2650
Formation of cell membranes2300
Osmotic control: K+, Na+, Cl-, (Ca2+)2300
Release of CO2, H2800-2000
Anaerobic metabolism of organic materials through fermentation2000
Ionic signals: Ca2+1400-2100
Advanced forms of fermentation, high control and organization (filaments).
Vesicles (eukaryoyes).
Foundations of photosynthesis (pigmented cells)1400
Photosynthesis (Mn) begins
m CO2 + n H2 -> m(H2)n + m O2
Respiration (Cu) begins800
Release of substantial CO20-800
Significant quantities of oxygen forbidden:
O2<0.001 present atmospheric level.
UV 120-300 nm at 0-10 km altitude depending on atmospheric H2O vapour.
UV 210-300 nm penetrates 5-10 m of liquid H2O.
Foundation of oxygen atmosphere
Multicellular Organisms
UV 210-300 nm at surface slowly attenuated0-1300
Many cellular organelles have appeared570
Many multi-cellular organisms have appeared570


Reference: pp.17, 513 of "The Biological Chemistry of the Elements: The Inorganic Chemistry of Life" by J. J. R. Frausto da Silva and R. J. P. Williams, Clarendon Press, Oxford, 1991 (ISBN=0-19-855802-3).