Sexual selection is thought to be responsible for the rapid divergent evolution of male genitalia with several studies detecting multivariate sexual selection on genital form. However, in most cases, selection is only estimated during a single episode of selection, which provides an incomplete view of net selection on genital traits. Here we estimate the strength and form of multivariate selection on the genitalia arch of Drosophila simulans when mating occurs in the absence of a competitor and during sperm competition, in both sperm defence and offense roles (i.e. when mating first and last). We found that the strength of sexual selection on the genital arch was strongest during non-competitive mating and weakest during sperm offense. However, the direction of selection was similar across selection episodes with no evidence for antagonistic selection. Overall, selection was not particularly strong despite genitals clearly evolving rapidly in this species. This article is protected by copyright. All rights reserved.

中文翻译：

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雄性拟果蝇生殖叶的性选择

性选择被认为是男性生殖器快速分化进化的原因，几项研究检测到生殖器形式的多变量性选择。然而，在大多数情况下，选择仅在单个选择阶段进行估计，这提供了对生殖特征的净选择的不完整视图。在这里，我们估计了在没有竞争者的情况下和精子竞争期间，在精子防御和进攻角色（即首先和最后交配时）交配时，模拟果蝇生殖器弓上的多元选择的强度和形式。我们发现生殖弓上的性选择强度在非竞争性交配期间最强，而在精子进攻期间最弱。然而，选择的方向在选择情节中是相似的，没有对抗选择的证据。总体而言，尽管该物种的生殖器明显快速进化，但选择并不是特别强。本文受版权保护。版权所有。