Kozak Genevieve M, Reisland Melissa, Boughmann Janette W
Department of Zoology, University of Wisconsin, Madison Wisconsin 53706, USA.
Evolution. 2009 Feb;63(2):353-65. doi: 10.1111/j.1558-5646.2008.00564.x. Epub 2008 Dec 19.
Sexual isolation is often assumed to arise because choosy females recognize and reject heterospecific males as mates. Yet in taxa in which both males and females are choosy, males might also recognize and reject heterospecific females. Here, we asked about the relative contribution of the sexes to the strong sexual isolation found in limnetic-benthic species pairs of threespine sticklebacks, which show mutual mate choice. We asked whether males and females of the two species recognize conspecifics and also prefer to mate with them. We found evidence for mate recognition by both sexes but only females prefer conspecifics. The nature of male courtship depended on which species of female they were courting, indicating that males recognized conspecific females and differentiated them from heterospecifics. However, males courted both species of females with equal vigor and changed courtship in a manner that would increase the chance of mating with heterospecifics. Females both recognized conspecifics and strongly preferred them. They responded very little to heterospecific male courtship and almost never mated with them. Therefore, males are likely to undermine sexual isolation, but females uphold it. Despite mutual mate choice and mate recognition in both sexes, females are primarily responsible for sexual isolation in these taxa.
性隔离通常被认为是由于挑剔的雌性识别并拒绝异种雄性作为配偶而产生的。然而，在雄性和雌性都挑剔的分类群中，雄性也可能识别并拒绝异种雌性。在这里，我们探讨了在三刺鱼的湖底-底栖物种对中发现的强烈性隔离中，两性的相对贡献，这些物种对表现出相互择偶。我们询问这两个物种的雄性和雌性是否能识别同种个体，并也更愿意与它们交配。我们发现两性都有配偶识别的证据，但只有雌性更喜欢同种个体。雄性求爱的性质取决于它们求爱的是哪种雌性，这表明雄性识别同种雌性并将它们与异种雌性区分开来。然而，雄性对两种雌性都同样积极地求爱，并以一种会增加与异种交配机会的方式改变求爱行为。雌性既能识别同种个体，也强烈偏好同种个体。它们对异种雄性的求爱反应很少，几乎从不与它们交配。因此，雄性可能会破坏性隔离，但雌性会维持它。尽管两性都有相互择偶和配偶识别，但在这些分类群中，雌性主要负责性隔离。
