The Institute of Statistical Mathematics, 10-3 Midori-cho, Tachikawa, Tokyo, 190-8562, Japan.
Department of Fish Ecology and Evolution, Center for Ecology, Evolution & Biogeochemistry, Swiss Federal Institute of Aquatic Science and Technology, 6047, Kastanienbaum, Switzerland.
Ecol Lett. 2018 Feb;21(2):264-274. doi: 10.1111/ele.12891. Epub 2017 Dec 14.
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 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.
理解快速适应辐射的机制一直是进化生态学的核心问题。最近，人们越来越认识到，不同进化谱系之间的杂交可以通过创造新的表型来促进适应辐射。然而，由于杂交可能否定预先存在的物种丰富度，因此该假说的理论合理性仍不清楚。在这里，我们使用基于个体的模型从理论上研究了杂交是否以及在什么条件下可以促进生态物种形成和适应辐射，该模型用于模拟两个异地进化谱系杂交后基因组的进化。该模型表明，杂交产生的杂种优势可以促进适应辐射，当新的空闲生态位高度不同、突变的表型效应大小较小时，以及亲本组群之间存在中度遗传分化时，这种促进作用最为显著。这些结果为杂交促进适应辐射的效果提供了理论依据。
