An evolutionary approach to homosexual behavior in Poeciliid fishes.

[摘要] The paper is an opinion. It is known that mate choice in vertebrates is based on certainmorpho-physiological criteria that translate into health and vigor of a potential mate. This is the typicalpreference, specific to most individuals, which provides the individual and most of his descendants withthe best reproductive fitness. However, there are individuals with an atypical preference, which is oftenvariable, for instance: the preference of a male for masculine females, preference of a female foreffeminate males, preference of a normal individual for hermaphrodites, preference for individualsbelonging to other species, homosexual preference, etc. These individuals which express abnormalbehavior have a reduced reproductive fitness and produce fewer offspring under normal circumstances.At a first view, like other atypical preferences, homosexual behavior does not give the individual anyselective advantage, but it is detrimental because it does not bring a greater number of descendants.Then we ask why this detrimental behavior does not disappear by natural selection. Homosexualbehavior should be seen as an atypical preference of the individual for choosing a mating partner.Surprisingly, from time to time atypical preferences might be decisive factors in species survival andevolution.

[学科分类] 水产科学

[关键词] homosexual behavior;Poeciliids;evolution;fitness;survival.