1. The History of Life on Earth

2. Space-time 13.7bya: Universe (Microwave Background Radiation)
4.6bya: Sun & Earth (Zircon)

4. Hadean Eon (4.6-3.9bya) Physics: free energy
Chemistry: inorganic molecules (anaerobic)

5. Archean Eon (3.9-2.5bya) Physics: free energy
Chemistry: inorganic molecules (H2O)
Biology #1: prokaryotic life (3.9bya)
Simplest Life:
Macromolecules
Cell
Replicate

6. Archean Eon (3.9-2.5bya) Primordial Soup Hypothesis
Miller & Urey: synthesized 20 amino acid monomers
Sutherland: synthesized 2 RNA nucleotide monomers
Hanczyc: synthesized lipid cells/replication events

7. Archean Eon (3.9-2.5bya) Other Abiogenesis Models
Exogenesis Hypothesis
Clay Hypothesis
Radioactive Beach Hypothesis
Thermodynamic Dissipation Hypothesis
Polycyclic Aromatic Hydrocarbon Hypothesis…

8. Archean Eon ( bya)
Biology #2: photosynthesis (2.7bya)

9. Proterozoic Eon (2.5-.5bya)
Biology #3: eukaryotic life (2.1bya)
Endosymbiosis Theory:
Mitochondria & Chloroplasts
Contain own DNA
Small circular
Double membrane
Replicate independently
Binary fission
Cell doesn’t make them

10. Phanerozoic Eon (.5-0bya)
Biology #4: multicellular life (.575bya)
Protists
Plants, Fungi, & Animals

11. Phanerozoic Eon (.5-0bya)
Biology #5: colonizing land (.5bya)

12. Phanerozoic Eon (now)

13. Phanerozoic Eon
Diversification-Extinction-Diversification-Extinction…

14. 3 of 5 Mass Extinctions
450 mya 250 mya 65 mya 90% 96% 75%

15. 6th Mass Extinction
Currently, x normal extinction rate

16. 7th Extinction