Lecture 1: Early Life Timeline - 10/2

Question 1

1) Life appeared
Atmosphere composed of CH4, NH4, SO2, CO2, H2S, H2 (no O2)

Answer 1

4.1 x 10^9 years ago

Question 1

Big Bang

Answer 1

13.8 x 10^9 years ago

Question 2

2) Primitive photosynthesis
No O2 released from photosynthesis yet (from splitting water)
Only S from H2S was released

Answer 2

3.5 x 10^9 years ago

Question 3

3a) Photosynthesis
H & e- from water and O2 released

Answer 3

3.0 x 10^9 years ago

Question 4

4) Complex cells
Eukaryotes evolved due to endosymbiosis

Answer 4

2.0 x 10^9 years ago

Question 5

5) Plants and insects move onto land

Answer 5

475-430 x 10^6 years ago

Question 6

Dominance of swamps on earth

Answer 6

350-300 x 10^6 years ago

Question 7

6) Evolution of early fern tree forests in the Carboniferous period

Answer 7

390-350 x 10^6 years ago

Question 8

7) Appearance of conifers and cone-bearing plants dominate, evolution of the seed

Answer 8

230-145 x 10^6 years ago

Question 9

8) Angiosperms and
9) Flowers evolve in Cretaceous period

Answer 9

140 x 10^6 years ago

Question 10

Grasses appear

Answer 10

55 x 10^6 years ago

Question 11

Start of agriculture

Answer 11

~10,000 years ago