Evolution and Diversity
Subject:
Biology [1]
Tags:
Animal Diversity [3]
The Origins of Life Todays Atmosphere Contains 78% Nitrogen and 21% Oxygen Also has small amounts of CO2, helium and, neon ? Heterotroph hypothesis: a theory which stated that there was more lightning, volcanic activity, and UV radiation H2, NH3, CH4, and H2O were the first molecules that were present The early earth DID NOT contain oxygen ? Heterotrophs: first cells in life They can't synthesize their own food ? Autotrophs: organisms that make their own food using solar energy Formed because food was scarce for heterotrophs Oxygen was a waste product of early autotrophs ? The first organisms in life were anaerobic Today most organisms are aerobic ? Evolution Gene pool: genes of a large population of people ?