BIOL-3030 Lecture Notes - Lecture 15: Basal Rate, Permian, Ectotherm
Document Summary
Fish draw heat from environment - maintain activity at body temp that is close to. Endothermy is not necessarily better than ectothermy environment around them they are ectotherms. Humans wouldn"t last ten minutes in a cold stream. Once in sauropsids (among birds and ancestors) Once in synapsids (among mammals and ancestors. Ectotherm - relies on external heat source to raise body temp. Endotherm - relies on internal heat source to raise body temp. Where animal gets its heat from not how hot it is. Internal heat of endotherms from two main sources: Basic processes producing and using energy to keep body from functioning. Ectotherms conduct both processes, but endotherm basal metabolism rates are higher, producing enough heat to warm body without external input. This means they produce more heat that is able to keep the body warm. About 5x higher basal rate in mammals and birds than in salamanders. High metabolic rate necessary, but not sufficient for endothermy.
