| A | B |
|---|
| an organ with no function in today's organism, but may have been useful in an ancestor | vestigial structure |
| the average form of a trait is favored | stabilizing selection |
| organisms that are best suited to the environment reproduce more successfully than other organisms | natural selection |
| the change of two or more species in close association with each other | coevolution |
| both extreme forms of a trait are favored | disruptive selection |
| idea that evolution occurs in sudden bursts and these bursts are separated by long periods of stability | punctuated equilibrium |
| a type of divergent evolution where many related species evolve from a single ancestral species | adaptive radiation |
| idea that all life comes from life | biogenesis |
| a type of evolution where two or more related populations or species be come more and more dissimilar | divergent evolution |
| a physical separation of the members of a population | geographical isolation |
| features in an organism that serve identical functions and look somewhat alike but not from common ancestors | analogous structure |
| a type of evolution where two organisms that are not closely related are becoming increasingly similar | convergent evolution |
| the process of genes moving from one population to another | gene flow |
| a barrier to successful breeding between two populations or groups in an area | reproductive isolation |
| the total genetic information available in a population | gene pool |
| idea that evolution occurs slow and steadily over a long period of time | gradualism |
| the phenomenon where allele frequencies in a population change as a result of random events | genetic drift |
| the oldest rock layer is on the bottom, while the youngest rock layer is on the top | law of superposition |
| an extreme form of a trait is favored | directional selection |
| any trace of a dead organism | fossil |
| similar features that originated in a shared or common ancestor | homologous structure |
