Ongoing additions  to Biology 102 Evolutionary Timeline

Below are the numbered "major events in the history of life on earth" that we are keeping track of on the timeline handout.  The time periods (or ranges, given in mya, millions of years ago) are approximate.  You should be aware of the general order of these and the approximate time (reference eons, eras and periods of geological time).  See also the chart that shows most of these in relationship to continental drift.

  1. Early Archean Eon (~3850 mya) - First prokaryotes (living cells)
  2. Early Archean Eon (~3700 mya) - First photosynthesis (anaerobic bacteria)
  3. Early Archean Eon (~3600 mya) - First O2-releasing photosynthesis (by ancestors of bluegreen bacteria) 
  4. Early Proterozoic Eon (~2700? - 1700 mya) - First eukaryotes, by a series of endosymbiotic events
  5. Early to mid Proterozoic Eon (2000-1700 mya) - First sexual reproduction
  6. Early to mid Proterozoic Eon (2100-1500 mya) - Multicellularity with differentiation of tissues
  7. Late Proterozoic Eon (1100-800) - First animals (sea)
  8. Late Proterozoic Eon (1100-800) - First fungi (sea)
  9. Late Proterozoic Eon, Ediacarian (Vendian) Period (670-540) - First animal fossils (soft-bodied forms)
  10. Early Phanerozoic Eon, Paleozoic Era, Cambrian Period (544 -505 mya) - Cambrian radiation of animal phyla.  First shelled animals
  11. Early to mid Paleozoic Era, Ordovician Period (505-438 mya) - First plants (land)
  12. Mid Paleozoic Era, Devonian Period (408-360 mya) - First seed plants (seed ferns, now extinct)
  13. Mid Mesozoic Era, late Jurassic Period (213-144 mya) - First flowering plants (Archaefructus)
  14. Early to mid Paleozoic Era, Ordovician Period (505-438 mya) or earlier - First terrestrial fungus, in a symbiotic association with algae or early plants
  15. Early to mid Paleozoic Era, late Cambrian Period (544-505 mya) - First vertebrates (fossil scales of jawless fish found)
  16. Mid to late Paleozoic Era, late Devonian Period (408-360 mya) - First land vertebrate (amphibian)
  17. Late Paleozoic Era, early Carboniferous Period (360-286 mya) - First shelled (amniote) egg (reptiles)
  18. End of Paleozoic Era (245 mya) - End of Permian extinction "event"
  19. Early Mesozoic Era, late Triassic Period (225 mya) - First mammals
  20. End of Mesozoic Era (65 mya) - End of Cretaceous extinction "event"
  21. Beginning of Cenozoic, beginning of Tertiary Period, Eocene Epoch Era (50 mya) - First primates
  22. End of Cenozoic Era, beginning Quaternary Period, Pleistocene Epoch (2 mya) - First Homo species