Editing Sexual selection (section)

=== Darwin ===

[[File:Darwin sexual caricature.gif|thumb |upright |Victorian cartoonists mocked Darwin's ideas about display in sexual selection. Here he is fascinated by the apparent [[steatopygia]] in the latest fashion.|alt=Victorian era cartoon of Darwin as a monkey looking at a woman in a bustle dress]]

{{Further|The Descent of Man, and Selection in Relation to Sex}}

Sexual selection was first proposed by Charles Darwin in ''[[On the Origin of Species]]'' (1859) and developed in ''[[The Descent of Man, and Selection in Relation to Sex]]'' (1871), as he felt that natural selection alone was unable to account for certain types of non-survival adaptations. He once wrote to a colleague that "The sight of a feather in a [[peahen|peacock]]'s tail, whenever I gaze at it, makes me sick!" His work divided sexual selection into male–male competition and female choice.<ref>{{cite journal |last=Darwin |first=Charles |author-link=Charles Darwin |title=On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection |journal=Journal of the Proceedings of the Linnean Society of London. Zoology |year=1858 |volume=3 |issue=9 |pages=46–50 |url=http://darwin-online.org.uk/converted/pdf/1858_species_F350.pdf |doi=10.1111/j.1096-3642.1858.tb02500.x |url-status=live |archive-url=https://web.archive.org/web/20121022104103/http://darwin-online.org.uk/converted/pdf/1858_species_F350.pdf |archive-date=22 October 2012 |doi-access=free }}</ref><ref name="Mendelson Safran 2021">{{cite journal |last1=Mendelson |first1=Tamra C. |last2=Safran |first2=Rebecca J. |title=Speciation by sexual selection: 20 years of progress |journal=[[Trends in Ecology & Evolution]] |date=2021 |volume=36 |issue=12 |pages=1153–1163 |doi=10.1016/j.tree.2021.09.004|pmid=34607719 |bibcode=2021TEcoE..36.1153M }}</ref>

{{blockquote|... depends, not on a struggle for existence, but on a struggle between the males for possession of the females; the result is not death to the unsuccessful competitor, but few or no offspring.<ref name=origin>[[Charles Darwin|Darwin, Charles]] (1859). ''On the Origin of Species'' (1st edition). Chapter 4, p. 88. "And this leads me to say a few words on what I call Sexual Selection. This depends ..." {{cite web |url=http://darwin-online.org.uk/content/frameset?viewtype=side&itemID=F373&pageseq=12 |title=Archived copy |access-date=2011-05-22 |url-status=live |archive-url=https://web.archive.org/web/20111105031643/http://darwin-online.org.uk/content/frameset?viewtype=side&itemID=F373&pageseq=12 |archive-date=2011-11-05 }}</ref>}}

{{blockquote |... when the males and females of any animal have the same general habits ... but differ in structure, colour, or ornament, such differences have been mainly caused by sexual selection.<ref name=origin />}}

These views were to some extent opposed by [[Alfred Russel Wallace]], mostly after Darwin's death. He accepted that sexual selection could occur, but argued that it was a relatively weak form of selection. He argued that male–male competitions were forms of natural selection, but that the "drab" peahen's coloration is itself adaptive as [[camouflage]]. In his opinion, ascribing mate choice to females was attributing the ability to judge standards of beauty to animals (such as [[beetle]]s) far too cognitively undeveloped to be capable of [[aesthetic]] feeling.<ref name="Wallace">{{cite web |last=Wallace |first=Alfred Russel |author-link=Alfred Russel Wallace |title=Note on Sexual Selection (S459: 1892) |url=http://people.wku.edu/charles.smith/wallace/S459.htm |publisher=Charles Smith |access-date=13 January 2017 |date=1892 |url-status=live |archive-url=https://web.archive.org/web/20170217215250/http://people.wku.edu/charles.smith/wallace/S459.htm |archive-date=17 February 2017}}</ref>

[[File:Tribolium castaneum87-300.jpg|thumb|Sexual selection protected [[flour beetle]]s from extinction in a ten-year experiment.<ref name="popben"/>|alt=Photograph of flour beetles]]

Darwin's ideas on sexual selection were met with scepticism by his contemporaries and not considered of great importance, until in the 1930s biologists decided to include sexual selection as a mode of natural selection.<ref>{{cite book |last=Miller |first=G. F. |year=2000 |title=The Mating Mind: How sexual choice shaped the evolution of human nature |publisher=Heinemann |location=London |isbn=978-0-434-00741-7 |page=24}}</ref> Only in the 21st century have they become more important in [[biology]]; the theory is now seen as generally applicable and analogous to natural selection.<ref name="Hosken2011">{{cite journal |last1=Hosken |first1=David J. |last2=House |first2=Clarissa M. |title=Sexual Selection |journal=Current Biology |date=January 2011 |doi=10.1016/j.cub.2010.11.053 |pmid=21256434 |volume=21 |issue=2 |pages=R62–R65 |s2cid=18470445 |doi-access=free |bibcode=2011CBio...21..R62H }}</ref> A ten-year study, experimentally varying sexual selection on [[flour beetle]]s with other factors held constant, showed that sexual selection protected even an [[Inbreeding|inbred]] population against extinction.<ref name="popben">[http://phys.org/news/2015-05-population-benefits-sexual-males.html Population benefits of sexual selection explain the existence of males phys.org May 18, 2015 Report] on a study by the [[University of East Anglia]] {{webarchive |url=https://web.archive.org/web/20150821000158/http://phys.org/news/2015-05-population-benefits-sexual-males.html |date=August 21, 2015 }}</ref>