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Mate choice or intersexual selection is an evolutionary process in which selection, normally of a male mate by a female chooser, is dependent on the attractiveness of his phenotypic traits. It is one of two components of sexual selection (the other being intrasexual selection). Charles Darwin first introduced his ideas on sexual selection in 1871 but they were initially rejected. Ronald Fisher then developed the idea in his 1915 paper ''The evolution of sexual preference''〔 outlined the Fisherian runaway theory in 1930. Advances in genetic and molecular biology techniques have accompanied major progress in this field recently. Five currently recognized mechanisms, which can co-occur, and for each of which there are many examples, explain the evolution of mate choice. In systems where mate choice exists, one sex is competitive with same-sex members and the other sex is choosy (selective when it comes to picking individuals to mate with). In most species, females are the choosy sex that discriminate amongst competitive males but there are several examples of reversed roles (see below). == Origins and history == Charles Darwin first expressed his ideas on sexual selection and mate choice in his book ''The Descent of Man, and Selection in Relation to Sex'' in 1871. He was perplexed by the elaborate ornamentation that males of some species have because - such features appeared to be detrimental to survival and to have negative consequences for reproductive success. Darwin proposed two explanations for the existence of such traits: these traits are useful in male-male combat or they are preferred by females.〔Darwin, C. 1871. ''The Descent of Man, and Selection in Relation to Sex''. John Murray, London.〕 This article focuses on the latter. Darwin treated natural selection and sexual selection as two different topics, although in the 1930s biologists defined sexual selection as being a part of natural selection.〔Miller, Geoffrey (2000). ''The mating mind: how sexual choice shaped the evolution of human nature'', London, Heineman, ISBN 0-434-00741-2 (also Doubleday, ISBN 0-385-49516-1) p.8〕 In 1915 Ronald Fisher wrote a paper on the evolution of female preference and secondary sexual characteristics. Fifteen years later, he expanded this theory in a book called ''The Genetical Theory of Natural Selection''. There he described a scenario where feedback between mate preference and a trait results in elaborate characters such as the long tail of the male peacock (see Fisherian runaway). In 1948, using ''Drosophila'' as a model, Angus J. Bateman presented experimental evidence that male reproductive success is limited by the number of mates obtained while female reproductive success is limited by the number of pregnancies that she can have in her lifetime. Thus a female must be selective when choosing a mate because the quality of her offspring depends on it. Males must fight, in the form of intra-sexual competition, for the opportunity to mate because not all males will be chosen by females. This became known as Bateman's principle, and although this was a major finding that added to the work of Darwin and Fisher, it was overlooked until George C. Williams emphasized its importance in the 1960s and 1970s.〔Williams, G.C. 1966. Adaptation and Natural Selection. Princeton University Press, Princeton, N.J.〕〔Williams, G. C. 1975. Sex and evolution. Princeton University Press, Princeton, N.J.〕 In 1972, soon after Williams' revival of the subject, Robert L. Trivers presented his parental investment theory. Trivers defined parental investment as any investment made by the parent that benefits his or her current offspring at the cost of investment in future offspring. These investments include the costs of producing gametes as well as any other care or efforts that parents provide after birth or hatching. Reformulating Bateman's ideas, Trivers argued that the sex that exhibits less parental investment (not necessarily the male) will have to compete for mating opportunities with the sex that invests more. The differences in levels of parental investment create the condition that favors mating biases.〔 Trivers, R.L. (1972). Parental investment and sexual selection. In B. Campbell (Ed.), Sexual selection and the descent of man, 1871-1971 (pp. 136–179). Chicago, IL: Aldine 〕 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「Mate choice」の詳細全文を読む スポンサード リンク
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