Segami Marzal Julia Carolina, Rudh Andreas, Rogell Björn, Ödeen Anders, Løvlie Hanne, Rosher Charlotte, Qvarnström Anna
Animal Ecology Department of Ecology and Genetics Uppsala University Uppsala Sweden.
Department of Zoology: Ecology Stockholm University Stockholm Sweden.
Ecol Evol. 2016 Dec 24;7(2):744-750. doi: 10.1002/ece3.2662. eCollection 2017 Jan.
Population divergence in sexual signals may lead to speciation through prezygotic isolation. Sexual signals can change solely due to variation in the level of natural selection acting against conspicuousness. However, directional mate choice (i.e., favoring conspicuousness) across different environments may lead to gene flow between populations, thereby delaying or even preventing the evolution of reproductive barriers and speciation. In this study, we test whether natural selection through predation upon mate-choosing females can favor corresponding changes in mate preferences. Our study system, , is an extremely color polymorphic neotropical frog with two distinctive antipredator strategies: aposematism and crypsis. The conspicuous coloration and calling behavior of aposematic males may attract both cryptic and aposematic females, but predation may select against cryptic females choosing aposematic males. We used an experimental approach where domestic fowl were encouraged to find digitized images of cryptic frogs at different distances from aposematic partners. We found that the estimated survival time of a cryptic frog was reduced when associating with an aposematic partner. Hence, predation may act as a direct selective force on female choice, favoring evolution of color assortative mating that, in turn, may strengthen the divergence in coloration that natural selection has generated.
性信号中的种群分化可能通过合子前隔离导致物种形成。性信号可能仅因针对显眼性的自然选择水平的变化而改变。然而，在不同环境中定向的配偶选择（即偏爱显眼性）可能导致种群间的基因流动，从而延迟甚至阻止生殖隔离和物种形成的进化。在本研究中，我们测试了通过捕食选择配偶的雌性，自然选择是否会有利于配偶偏好的相应变化。我们的研究系统是一种颜色极其多态的新热带蛙，具有两种独特的反捕食策略：警戒色和保护色。具警戒色的雄性的显眼颜色和鸣叫行为可能会吸引具保护色和具警戒色的雌性，但捕食可能会淘汰选择具警戒色雄性的具保护色雌性。我们采用了一种实验方法，鼓励家禽在不同距离寻找与具警戒色配偶在一起的具保护色蛙的数字化图像。我们发现，当与具警戒色的配偶在一起时，具保护色蛙的估计存活时间会缩短。因此，捕食可能作为对雌性选择的直接选择力，有利于颜色分类交配的进化，这反过来可能会加强自然选择所产生的颜色差异。
