https://www.khanacademy.org/science/hs-bio/x230b3ff252126bb6:mechanisms-of-evolution-hs/x230b3ff252126bb6:mechanisms-of-evolution/v/natural-selection-and-evolution 2022-09-24T04:45:13.131282509Z Natural selection and evolution Evolution is a consequence of the interaction of four factors: (1) the potential for a species to increase in number, (2) the genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for an environment’s limited supply of the resources that individuals need in order to survive and reproduce, and (4) the ensuing proliferation of those organisms that are better able to survive and reproduce in that environment. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/3627aa50-5b18-4499-b04a-c5d4fe9d6868_1280_720_base.png Natural selection and evolution Evolution is a consequence of the interaction of four factors: (1) the potential for a species to increase in number, (2) the genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for an environment’s limited supply of the resources that individuals need in order to survive and reproduce, and (4) the ensuing proliferation of those organisms that are better able to survive and reproduce in that environment. https://cdn.kastatic.org/ka-youtube-converted/ifyEocJ2Rog.mp4/ifyEocJ2Rog.mp4 390 Natural selection as the primary mechanism of evolution https://www.khanacademy.org/science/hs-bio/x230b3ff252126bb6:mechanisms-of-evolution-hs/x230b3ff252126bb6:mechanisms-of-evolution/e/understand-natural-selection-and-evolution 2026-05-05T05:30:46.642833846Z Understand: Natural selection and evolution Check your understanding of natural selection and evolution in this set of free, standards-aligned practice questions. exercise https://www.khanacademy.org/science/ms-biology/x0c5bb03129646fd6:natural-and-artificial-selection/x0c5bb03129646fd6:natural-selection/e/understand-natural-selection-ms 2026-06-09T15:11:13.630156547Z Understand: Natural selection Check your understanding of natural selection in this set of free, standards-aligned practice questions. Megan Cohn exercise https://www.khanacademy.org/science/ap-biology/natural-selection/natural-selection-ap/a/darwin-evolution-natural-selection 2026-04-30T05:40:35.129589872Z Learn: Darwin, evolution, & natural selection Learn about Charles Darwin's voyage on the HMS Beagle and his ideas about evolution and natural selection. article