Adaptive Evolution

Natural selection drives adaptive evolution by selecting for and increasing the occurrence of beneficial traits in a population.

Stabilizing, directional, and diversifying selection either decrease, shift, or increase the genetic variance of a population.

In frequency-dependent selection, phenotypes that are either common or rare are favored through natural selection.

Sexual selection, the selection pressure on males and females to obtain matings, can result in traits designed to maximize sexual success.

Natural selection cannot create novel, perfect species because it only selects on existing variations in a population.