Data from: Female choosiness leads to the evolution of individually distinctive males

Individual recognition is a taxonomically widespread ability that underlies a diverse suite of behaviors including the identification of individual nest-mates, agonistic opponents, and mating partners. However, as yet relatively little is known about the circumstances under which the requisite signal diversity can evolve. Here we develop a model describing a novel mechanism of individual identity evolution via sexual selection. Females choose among a subset of males, but can select the most attractive male only when he bears a unique identity signal. This mimics a species in which mate assessment and choice are temporally separate, such as when females observe males in direct conflict and must subsequently locate the winner. When females in our model are choosy at least 10% of the time, diversity at individuality signaling loci evolves as a by-product of selection on male attractiveness more rapidly than does diversity at equivalent loci evolving only under neutral processes. Even at lower discrimination rates, drifting signal diversity gives the female choice mechanism sufficient traction to drive up average male attractiveness. The mechanism we describe here can significantly increase signal diversity at even low rates of discrimination by females.

个体识别（individual recognition）是一种在分类学上广泛分布的能力，是一系列行为的核心基础，涵盖同巢个体识别、敌对对手（agonistic opponents）识别与交配伴侣识别。然而截至目前，学界对必要信号多样性得以演化的具体条件仍知之甚少。本研究构建了一个模型，用以阐释个体识别信号经由性选择（sexual selection）演化的全新机制。雌性会在雄性子集内开展择偶，但仅当某雄性携带独特的识别信号时，才能选中最具吸引力的雄性个体。该模型模拟了配偶评估与选择在时间上相互分离的物种场景，例如雌性先观察雄性间的直接争斗，随后需定位获胜雄性的情境。当模型中的雌性至少有10%的时间处于择偶挑剔状态时，个体信号基因座（individuality signaling loci）的多样性会作为雄性吸引力选择的副产物得以演化，其演化速度快于仅在中性过程（neutral processes）下演化的等效基因座多样性。即便雌性的识别率较低，漂变产生的信号多样性也能为雌性选择机制提供足够的作用强度，以提升雄性的平均吸引力水平。本研究所阐释的这一机制，即便在雌性识别率较低的情况下，也能显著提升信号多样性水平。