Data from: Female preference for male courtship effort can drive the evolution of male mate choice

The evolution of male mate choice is constrained by costs of choice in species with a male-biased operational sex ratio. Previous theoretical studies have shown that significant benefits of male choice are required, e.g., by mating with more fecund females, in order for these costs to be offset and a male preference to spread. In a series of population genetic models we show the novel effect that male mating preference, expressed as a bias in courtship, can spread when females prefer, and thus are more likely to mate with, males who court more. We explore two female preference functions for levels of male courtship, one representing a threshold and the other a weighted female preference. The basic finding generally holds for both preference functions. However, the preference function greatly affects the spread of a male preference allele after the addition of competing males who can court more in total. Our results thus stress that a thorough understanding of the response of females to male courtship is a critical component to understanding male preference evolution in polygynous species.

在雄性偏向的操作性别比（operational sex ratio）物种中，雄性配偶选择的演化过程受到选择成本的约束。既往理论研究表明，若要抵消此类选择成本并推动雄性偏好扩散，雄性选择需具备显著收益——例如通过与繁殖力更强的雌性交配实现。本研究通过一系列种群遗传模型，揭示了一项全新效应：当雌性偏好更频繁求偶的雄性、并因此更倾向于与这类雄性交配时，以求偶偏好形式体现的雄性交配偏好同样能够扩散。我们针对雄性求偶水平设置了两类雌性偏好函数：一类为阈值型偏好函数，另一类为加权型偏好函数。两类偏好函数下，本研究的核心发现均普遍成立。但当引入总求偶频次更高的竞争性雄性后，雌性偏好函数会对雄性偏好等位基因（allele）的扩散过程产生显著影响。因此，本研究结果强调，若要解析一夫多妻制物种（polygynous）中雄性偏好的演化机制，深入理解雌性对雄性求偶行为的响应模式是不可或缺的关键环节。