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Fisherian or Fisher's runaway, first proposed by Ronald Fisher in the early 20th century, is a hypothesized genetic sexual selection mechanism for the evolution of exaggerated male ornamentation (a subtype secondary sexual characteristic) observed in numerous species that produce offspring through sexual reproduction; based upon female choice, the preference or attraction of females for ornamented male mates.〔Fisher, R.A. (1915) The evolution of sexual preference. Eugenics Review (7) 184:192〕〔Fisher, R.A. (1930) The Genetical Theory of Natural Selection. ISBN 0-19-850440-3〕〔Edwards, A.W.F. (2000) Perspectives: Anecdotal, Historial and Critical Commentaries on Genetics. The Genetics Society of America (154) 1419:1426〕〔Andersson, M. (1994) Sexual selection. ISBN 0-691-00057-3〕〔Andersson, M. and Simmons, L.W. (2006) Sexual selection and mate choice. Trends, Ecology and Evolution (21) 296:302〕〔Gayon, J. (2010) Sexual selection: Another Darwinian process. Comptes Rendus Biologies (333) 134:144〕 The evolution of male ornamentation, an example being the colourful and elaborate peacock plumage compared to the relatively subdued peahen plumage, represented a paradox for evolutionary biologists in the period following Charles Darwin and leading up to the modern evolutionary synthesis; the selection for costly ornaments appeared to biologists at the time as being incompatible with natural selection. Fisherian runaway was an attempt to resolve this paradox using an assumed genetic basis for both the preference and the ornament, and through the powerful forces of sexual selection. Fisherian runaway hypothesizes that females choose "attractive" males with the most exaggerated ornaments based solely upon the males' possession of that ornament. According to Fisher, if strong enough, female preference for exaggerated ornamentation in mate selection could be enough to undermine natural selection if the ornament under sexual selection is otherwise non-adaptive. Fisher hypothesized this counteraction would result in the next generation's male offspring being more likely to possess the ornament and female offspring more likely to possess the preference for the ornament than the previous generation. Over subsequent generations this would lead to the runaway selection via a positive feedback mechanism for males who possess the most exaggerated ornaments.〔〔〔Halliburton, R. (2004) Introduction to Population Genetics. ISBN 0-13-016380-5〕 Fisherian runaway sought to explain the paradox of male ornamentation but neither the mechanism nor the secondary sexual characteristic or preference is restricted to this system: Fisherian runaway can be applied to include sexually dimorphic phenotypic traits and character structures such as behaviour and structural displays expressed by either sex.〔〔〔〔 Fisherian runaway has been difficult to demonstrate empirically, despite being theoretically plausible, due in part to the difficulty of detecting the genetic mechanism and the process by which it is initiated.〔〔 ==Historical context== R.A. Fisher was, like Charles Darwin before him, fascinated by the mechanics of sexual selection."〔〔 Darwin's published a book on sexual selection in 1871 called ''The Descent of Man, and Selection in Relation to Sex'',〔Darwin, C. (1871) The Descent of Man, and Selection in Relation to Sex. ISBN 978-1-57392-176-3〕 which garnered interest upon its release but by the 1880s the ideas had been deemed too controversial and largely neglected. The interest Fisher and a few others had in sexual selection〔〔 was not shared, however, by the vast majority of his peers in the early developments of the modern evolutionary synthesis, being ignored by biologists until the second half of the 20th century. When Alfred Russel Wallace stated that animals show no sexual preference in his 1915 paper, ''The evolution of sexual preference'' Fisher publicly disagreed.〔 Fisher, in the foundational 1930 book, ''The Genetical Theory of Natural Selection'',〔 first outlined a model by which runaway inter-sexual selection could lead to sexually dimorphic male ornamentation based upon female choice and a preference for "attractive" but otherwise non-adaptive traits in male mates. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Fisherian runaway」の詳細全文を読む スポンサード リンク
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