âº a gradual process of change and development. âº biology Evolution is the process by which the physical characteristics of types of creatures change over time, new types of creatures develop, and others disappear. (Definition of âevolutionâ from the Cambridge Academic Content Dictionary Â© Cambridge University Press)
You can remember the difference between endotherms and ectotherms if you remember that endo- means inside endo- = inside and ecto- means outside ecto- = outside, so endotherms generate their own heat from within, and ectotherms get their heat from the outside.
Reptiles and fish are cold-blooded animals, they get their heat from the environment. All mammals are warm-blooded, and humans are mammals. Warm-blooded species make their own body heat and can maintain a body temperature higher than their environment. Warm-blooded animals â mammals and birds â have body temperatures that usually stay roughly the same, even in cold temperatures.