Unit 6 - Major Events w/ Times

Question 1

Formation of life

Answer 1

First evidence of life was found in the Archean Eon (4-2.5 bya), simple prokaryotic organisms like bacteria and archaea

Question 2

Oxygen Revolution

Answer 2

Happened during the Proterozoic Eon, oxygen gas first accumulated in the atmosphere and surface ocean and the levels kept rising, allowed for photosynthesis and aerobic respiration

Question 3

Cambrian Explosion

Answer 3

Cambrian Period (542-488 mya) had the Cambrian Explosion, which marked the rapid diversification of complex, multicellular life–many animals we still have today

Question 4

First terrestrial life

Answer 4

Devonian Period (416-359 mya), tetrapods and insects

Question 5

Permian Extinction

Answer 5

Permian Period (299-252 mya) marked the largest extinction in history, affecting diversity and especially marine communities

Question 6

K-T Event

Answer 6

Marks the end of the Cretaceous Period (145-65.5 mya), when the big asteroid hit and dinosaurs went extinct :(

Question 7

Separation of Pangaea

Answer 7

It started to break up in the early-mid Mesozoic Era (so like the early Jurassic Period, 225 mya) and it’s been splitting until today

Question 8

Movement of Primates out of trees onto land

Answer 8

Started after the Paleogene Period (65.5-23 mya), when primates lived on trees entirely