Editing Microevolution (section)

===Selection===
{{Main|Natural selection|Artificial selection}}
''Selection'' is the process by which [[heritable]] [[trait (biology)|traits]] that make it more likely for an [[organism]] to survive and successfully [[reproduction|reproduce]] become more common in a [[population]] over successive generations.

It is sometimes valuable to distinguish between naturally occurring selection, natural selection, and selection that is a manifestation of choices made by humans, artificial selection. This distinction is rather diffuse. Natural selection is nevertheless the dominant part of selection.
[[File:Mutation and selection diagram.svg|thumb|right|300px|Natural selection of a population for dark coloration]]
The natural [[genetic variability|genetic variation]] within a population of organisms means that some individuals will survive more successfully than others in their current [[ecosystem|environment]]. Factors which affect reproductive success are also important, an issue which [[Charles Darwin]] developed in his ideas on [[sexual selection]].

Natural selection acts on the [[phenotype]], or the observable characteristics of an organism, but the [[Genetics|genetic]] (heritable) basis of any phenotype which gives a reproductive advantage will become more common in a population (see [[allele frequency]]). Over time, this process can result in [[adaptation]]s that specialize organisms for particular [[ecological niche]]s and may eventually result in the speciation (the emergence of new species).

Natural selection is one of the cornerstones of modern [[biology]]. The term was introduced by Darwin in his groundbreaking 1859 book ''[[On the Origin of Species]]'',<ref name=origin>Darwin C (1859) ''[[The Origin of Species|On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life]]'' John Murray, London; modern reprint {{cite book|author1=Charles Darwin |author2=Julian Huxley |year = 2003|title = The Origin of Species| publisher = Signet Classics|isbn = 978-0-451-52906-0}} Published online at [http://darwin-online.org.uk/ The complete work of Charles Darwin online]: [http://darwin-online.org.uk/content/frameset?itemID=F373&viewtype=side&pageseq=2 On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life].</ref> in which natural selection was described by analogy to [[artificial selection]], a process by which animals and plants with traits considered desirable by human breeders are systematically favored for reproduction. The concept of natural selection was originally developed in the absence of a valid theory of [[heredity]]; at the time of Darwin's writing, nothing was known of modern genetics. The union of traditional [[Darwinism|Darwinian evolution]] with subsequent discoveries in [[classical genetics|classical]] and [[molecular genetics]] is termed the ''[[Extended evolutionary synthesis|modern evolutionary synthesis]]''. Natural selection remains the primary explanation for [[adaptive evolution]].