Editing Natural selection (section)

==Terminology==

The term ''natural selection'' is most often defined to operate on heritable traits, because these directly participate in evolution. However, natural selection is "blind" in the sense that changes in phenotype can give a reproductive advantage regardless of whether or not the trait is heritable. Following Darwin's primary usage, the term is used to refer both to the evolutionary consequence of blind selection and to its mechanisms.<ref name="origin" /><ref name="fisher">{{harvnb|Fisher|1930}}</ref><ref name="nomenclature1">{{harvnb|Williams|1966}}</ref><ref>{{harvnb|Endler|1986}}</ref> It is sometimes helpful to explicitly distinguish between selection's mechanisms and its effects; when this distinction is important, scientists define "(phenotypic) natural selection" specifically as "those mechanisms that contribute to the selection of individuals that reproduce", without regard to whether the basis of the selection is heritable.<ref name="nomenclature2">{{harvnb|Haldane|1954}}</ref><ref>{{cite journal |last1=Lande |first1=Russell |author-link1=Russell Lande |last2=Arnold |first2=Stevan J. |date=November 1983 |title=The Measurement of Selection on Correlated Characters |journal=[[Evolution (journal)|Evolution]] |volume=37 |issue=6 |pages=1210–1226 |doi=10.2307/2408842 |jstor=2408842|pmid=28556011 }}</ref><ref>{{harvnb|Futuyma|2005}}</ref> Traits that cause greater reproductive success of an organism are said to be ''selected for'', while those that reduce success are ''selected against''.<ref>{{harvnb|Sober|1993}}</ref>