Data from: Hybridization can promote adaptive radiation by means of transgressive segregation

Understanding the mechanisms of rapid adaptive radiation has been a central problem of evolutionary ecology. Recently, there is a growing recognition that hybridization between different evolutionary lineages can facilitate adaptive radiation by creating novel phenotypes. Yet, theoretical plausibility of this hypothesis remains unclear because, for example, hybridization can negate pre-existing species richness. Here, we theoretically investigate whether and under what conditions hybridization promotes ecological speciation and adaptive radiation by using an individual-based model to simulate genome evolution following hybridization between two allopatrically evolved lineages. The model demonstrated that transgressive segregation through hybridization can facilitate adaptive radiation, most powerfully when novel vacant ecological niches are highly dissimilar, phenotypic effect size of mutations is small, and there is moderate genetic differentiation between parental lineages. These results provide a theoretical basis for the effect of hybridization facilitating adaptive radiation.解析快速适应辐射（rapid adaptive radiation）的形成机制，长期以来都是进化生态学（evolutionary ecology）领域的核心科学问题。近年来，学界逐渐认识到，不同演化支系（evolutionary lineages）间的杂交可通过催生新型表型（phenotypes），推动适应辐射的发生。然而，该假说的理论合理性仍有待明确——例如，杂交过程有可能抵消已有的物种丰富度。本研究构建基于个体的模型（individual-based model），模拟两个异域分化的演化支系杂交后的基因组演化（genome evolution）过程，从理论层面探讨杂交是否以及在何种条件下能够促进生态物种形成（ecological speciation）与适应辐射。模型结果显示，杂交引发的超亲分离（transgressive segregation）能够有效促进适应辐射，在以下场景中该效应最为显著：新生的空白生态位（ecological niches）差异极大、突变的表型效应量（phenotypic effect size）较低，且亲本支系间存在中等程度的遗传分化（genetic differentiation）。本研究结果为“杂交促进适应辐射”这一论点提供了坚实的理论依据。