Coupling genetic and ecological-niche models to examine how past population distributions contribute to divergence
Coupling genetic and ecological-niche models to examine how past population distributions contribute to divergence
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DOI：
10.1016/j.cub.2007.04.033
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发表时间：
2007-06-05
期刊：
影响因子：
9.2
通讯作者：
Keat, Marcia L.
中科院分区：
文献类型：
--
作者：
Knowles, L. Lacey;Carstens, Bryan C.;Keat, Marcia L.
了解气候引起的分布变化对物种分化的影响，就像那些伴随着更新世冰川周期[1，2]，需要明确地将过去分布的地理配置纳入遗传分化分析的工具。根据物种的历史分布，遗传差异可能会在祖先源种群之间积累，但长期以来一直存在争议的是，迁移到冰川避难所是否会促进分歧。在这里，我们将基于聚结的遗传模型[3，4]与生态位建模[5，6]相结合，以基于推断的物种过去分布来生成对遗传变异模式的预期。在末次盛冰期的山地蝗虫物种的分布重建表明，Melanoplus marshalli人口从天空岛屿的科罗拉多和犹他州可能是殖民地从多个祖先的源种群。遗传分析提供了令人信服的证据表明，M. marshalli -即多个避难所的空间分离-有利于遗传分化。遗传和生态位模型的耦合提供了一种新的灵活的工具，用于将古环境细节整合到种群结构的物种特异性预测中，这可以增加我们对为什么冰川循环促进了某些类群的物种形成而抑制了其他类群的多样性的理解[7，8]。
Understanding the impact of climate-induced distributional shifts on species divergence, like those accompanying the Pleistocene glacial cycles [1, 2], requires tools that explicitly incorporate the geographic configuration of past distributions into analyses of genetic differentiation. Depending on the historical distribution of species, genetic differences may accumulate among ancestral source populations, but there is long-standing debate whether displacements into glacial refugia promoted divergence. Here we integrate coalescent-based genetic models [3, 4] with ecological-niche modeling [5, 6] to generate expectations for patterns of genetic variation based on an inferred past distribution of a species. Reconstruction of the distribution of a montane grasshopper species during the last glacial maximum suggests that Melanoplus marshalli populations from the sky islands of Colorado and Utah were likely colonized from multiple ancestral source populations. The genetic analyses provide compelling evidence that the historical distribution of M. marshalli - namely, spatial separation of multiple refugia-was conducive to genetic differentiation. The coupling of genetic and ecological-niche modeling provides a new and flexible tool for integrating paleoenvironmental details into species-specific predictions of population structure that can increase our understanding of why the glacial cycles promoted speciation in some taxa and yet inhibited diversification in others [7, 8].