ANTHRO 7 Chapter Notes - Chapter 9: K–Ar Dating, Radiometric Dating, Continental Drift
Document Summary
Fauna dominated by therapsids diverse group of reptiles that possessed warm-blooded and hairy traits which linked them to mammals that evolved later. One therapsid lineage evolved and diversified to become the first true mammals. Mouse-sized, nocturnal, fed on seeds and insects. Placental and marsupial mammals that bore live young had evolved. Complex adaptations are assembled gradually, in many small steps that are favored by natural selection. To understand the evolution of our species, it is important to understand the geological climatic and biological conditions under which these evolutionary changes occurred. Evolution produces adaptation, but what is adaptive in one environment does. The world has become much colder and drier in the last 20 mil years. If the world became warmer, human ancestors may have remained in the safety of the trees and would not have become terrestrial or bipedal. Extremely variable in the last 800,000 years.
