Evolutionary Ecology Unit, Department of Biology, Lund University, Sölvegatan 37, 223 62 Lund, Sweden
Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2.
Biol Lett. 2018 Jun;14(6). doi: 10.1098/rsbl.2018.0124.
Ecological differences between the sexes are often interpreted as evidence of within-species ecological character displacement (ECD), a hypothesis with almost no direct tests. Here, we experimentally test two predictions that are direct corollaries of ECD between the sexes, in a salamander. First, we find support for the prediction that each sex has a growth rate advantage in the aquatic microhabitat where it is most commonly found. Second, we test the prediction that selection for ECD in the breeding environment may affect partial migration out of this environment. We found that phenotype-dependent migration resulted in a shift in the phenotypic distribution across treatments, with the highest sexual dimorphism occurring among residents at high founding density, suggesting that migration and ECD can both be driven by competition. Our work illustrates how complex patterns of habitat partitioning evolve during ECD between the sexes and suggest ECD and partial migration can interact to effect both ecological dynamics and evolution of sexual dimorphism.
性别之间的生态差异通常被解释为种内生态特征替代（ECD）的证据，而这一假设几乎没有直接的测试。在这里，我们在一种蝾螈中进行了两项直接推论 ECD 的实验测试。首先，我们发现支持以下预测的证据：在最常见的水生小生境中，每个性别都具有生长率优势。其次，我们测试了在繁殖环境中选择 ECD 可能会影响部分离开该环境的预测。我们发现，依赖表型的迁徙导致表型在处理之间的分布发生变化，在高创始密度的居民中出现了最高的性别二态性，这表明迁徙和 ECD 都可以受到竞争的驱动。我们的工作说明了性别之间的 ECD 如何导致栖息地分割的复杂模式进化，并表明 ECD 和部分迁徙可以相互作用，影响生态动态和性别二态性的进化。
