Evolution of a mating preference for a dual-utility trait used in intrasexual competition in genetically monogamous populations

The selection pressures by which mating preferences for ornamental traits can evolve in genetically monogamous mating systems remain understudied. Empirical evidence from several taxa supports the prevalence of dual-utility traits, defined as traits used both as armaments in intersexual selection and ornaments in intrasexual selection, as well as the importance of intrasexual resource competition for the evolution of female ornamentation. Here, we study whether mating preferences for traits used in intrasexual resource competition can evolve under genetic monogamy. We find that a mating preference for a competitive trait can evolve and affect the evolution of the trait. The preference is more likely to persist when the fecundity benefit for mates of successful competitors is large and the aversion to unornamented potential mates is strong. The preference can persist for long periods or potentially permanently even when it incurs slight costs. Our results suggest that, when females use o...

在遗传单配制（genetically monogamous）的交配体系中，塑造装饰性性状（ornamental traits）交配偏好演化的选择压力，迄今仍未得到充分研究。多项类群的实证证据表明，兼具双重功能的性状（dual-utility traits，即同时作为性间选择（intersexual selection）中的武器与性内选择（intrasexual selection）中的装饰的性状）普遍存在，同时性内资源竞争对雌性装饰性状演化的重要性也得到了证实。本研究旨在探讨：在遗传单配制体系下，针对用于性内资源竞争的性状的交配偏好是否能够发生演化。研究发现，对竞争性性状的交配偏好不仅能够演化，还会对该性状的演化产生影响。当成功竞争者的配偶所获得的繁殖力收益（fecundity benefit）较高，且对无装饰潜在配偶的厌恶程度较强时，该偏好更有可能得以维持。即便该偏好会带来轻微的适应成本，它仍能长期存续，甚至可能永久保留。我们的研究结果表明，当雌性利用o...