Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06511, USA.
Proc Natl Acad Sci U S A. 2012 Jul 3;109(27):10948-53. doi: 10.1073/pnas.1118378109. Epub 2012 Jun 11.
Early acquisition of mate preferences or mate-preference learning is associated with signal diversity and speciation in a wide variety of animal species. However, the diversity of mechanisms of mate-preference learning across taxa remains poorly understood. Using the butterfly Bicyclus anynana we uncover a mechanism that can lead to directional sexual selection via mate-preference learning: a bias in learning enhanced ornamentation, which is independent of preexisting mating biases. Naïve females mated preferentially with wild-type males over males with enhanced wing ornamentation, but females briefly exposed to enhanced males mated significantly more often with enhanced males. In contrast, females exposed to males with reduced wing ornamentation did not learn to prefer drab males. Thus, we observe both a learned change of a preexisting mating bias, and a bias in ability to learn enhanced male ornaments over reduced ornaments. Our findings demonstrate that females are able to change their preferences in response to a single social event, and suggest a role for biased learning in the evolution of visual sexual ornamentation.
早期获得配偶偏好或配偶偏好学习与广泛的动物物种的信号多样性和物种形成有关。然而，不同分类群中配偶偏好学习的机制多样性仍知之甚少。利用蝴蝶 Bicyclus anynana，我们发现了一种通过配偶偏好学习导致定向性选择的机制：对增强的装饰物的学习偏见，这与预先存在的交配偏见无关。天真的雌性优先与具有野生型翅膀装饰的雄性交配，而不是与具有增强翅膀装饰的雄性交配，但短暂暴露于增强雄性的雌性与增强雄性交配的频率显著更高。相比之下，暴露于翅膀装饰物减少的雄性的雌性不会学会更喜欢暗淡的雄性。因此，我们观察到既存在预先存在的交配偏见的学习变化，也存在对增强的雄性装饰物的学习能力相对于减少的装饰物的偏见。我们的发现表明，雌性能够根据单一的社会事件改变它们的偏好，并暗示有偏差的学习在视觉性装饰的进化中起作用。
