Evolution

A change in the heritable (genetic) characteristics of a population over successive generations; descent with modification.

The differential survival and reproduction of individuals due to heritable trait variation; individuals with favorable traits leave more offspring.

Heritable variation exists, more offspring are produced than can survive, and some variants confer a reproductive advantage, leading to adaptation.

An individual's relative reproductive success, that is, its contribution of offspring to the next generation, not physical strength.

A heritable trait that increases an organism's fitness in its environment, produced over generations by natural selection.

Structures with a shared evolutionary origin but possibly different functions (e.g., the forelimb bones of mammals); evidence of common ancestry.