History of Life Flashcards
When was the origin of life?
~3.8 bya
What was the first origin of life?
Chemosynthetic organisms in the ocean by the hydrothermal vents
When is the origin of photosynthesis?
~2.5 bya
“Oxygen Revolution”
Aerobic respiration evolves
What is the Cambrian Explosion (~500 mya)?
An explosion of life due to radiation
Developed the first carnivores
How many mass extinctions are there?
6
What classifies a mass extinction?
> 75% loss of species
What was significant about the Early Paleogene Period (~65 mya)?
Radiation of flowering plants, angiosperms, which led to two knew types of organisms such as nectar and fruit eaters
What is the importance of angiosperms?
Produce majority of O2
Primary productivity
Effect nitrogen and water cycle
2 new food sources
When does C4 photosynthesis develop?
Oligocene Epoch (~30 mya)
What are the different ways humans migrated to North America?
Land bridge
Coast of land bridge on boats
Many other ocean migratory routes
What is the anthropocene?
Current time period when human impact began
What is the Ordovician mass extinction?
444 mya
Global warming, anoxia, rising sea levels?
What is the Devonian mass extinction?
359 mya
Asteroid, reduced speciation
What is the Permian mass extinction?
252 mya
Volcanoes, glaciation, sea level drop?
What is the Triassic mass extinction?
201 mya
Volcanic release methane (warming)
