ANTH 102 Chapter Notes - Chapter 7: Adaptive Radiation, Homeothermy, Ecological Niche
Document Summary
Evolved from reptiles over 200 million years ago. With mass extinction of many reptiles 65 million years ago (including dinosaurs. ) Mammals had a greater choice off ecological niche. Ecological niche- functional position within a habitat: ecological niche includes. Climate: new niches opened as the earth cooled during this period. Mammals filled them: this led to a mammalian adaptive radiation. Rapid diversification of an evolving population following a change in the environment. They posed the biological means necessary to take advantage of the new opportunities available to them through the mass extinction: homeotherm. Ability to maintain a constant body temperature. Helped them survive in cold period after extinction period. A mammal can be active at a wide range of environmental temperature. A reptile (an isotherm) takes its body temperature though the surrounding environment becomes sluggish as the temperature drops around them: mammals require a high calorie dies to maintain constant body temperature.
