Long‐term isolation and stability explain high genetic diversity in the Eastern Himalaya
Long‐term isolation and stability explain high genetic diversity in the Eastern Himalaya
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DOI：
10.1111/mec.12619
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发表时间：
2014-02
影响因子：
4.9
通讯作者：
Yanhua Qu;P. Ericson;Qing Quan;G. Song;Ruiying Zhang;Bin Gao;F. Lei
中科院分区：
文献类型：
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作者：
Yanhua Qu;P. Ericson;Qing Quan;G. Song;Ruiying Zhang;Bin Gao;F. Lei
位于喜马拉雅东部的中国西南山区是全球关注的“生物多样性热点”。然而，是什么推动了这种独特的多样性，人们知之甚少。上新世晚期构造隆升导致西南山区地形起伏，形成了剧烈的生态分层，为生物迁移创造了物理障碍，并将生物隔离在不同的亚区和山系中。这与在该地区分布的4种鸟类（Alcippe morrisonia、Stachyridopsis ruficeps、Parus monticolus和agithalos concinus）的系统地理格局一致，它们在0.8 ~ 2.1 Ma之间融合，谱系之间存在较深的分裂。与这个纬度的其他地区不同，西南山区在很大程度上没有受到更新世冰川的影响。因此，在这些相当稳定的山地环境中，这些基因隔离的鸟类种群可以在整个更新世保持下来。相比之下，相同的四种分布在邻近的华中低地的种群的系统地理格局截然不同。该地区具有明显不同的地质历史，在更新世期间，气候引起了植被的剧烈变化。在这里，我们发现遗传变异的地理结构相当少，合并时间也年轻得多（0.3-0.7 Ma）。我们还发现了冰期基因瓶颈和间冰期基因流动的证据。研究结果表明，西南山区具有较高的遗传多样性，是在这些进化隔离且环境稳定的山地生境中长期存在的原位多样性的结果。
China's Southwest Mountainous Region in Eastern Himalaya is a ‘biodiversity hotspot’ of global interest for conservation. Yet little is known about what has driven this unique diversity. The dramatic topography of the Southwest Mountainous Region resulting from the tectonic uplift during the late Pliocene leads to dramatic ecological stratification, which creates physical barriers to migration and isolates organisms into different subregions and mountain systems. This agrees with the observation that the phylogeographical patterns found in four species of birds (Alcippe morrisonia, Stachyridopsis ruficeps, Parus monticolus and Aegithalos concinnus) distributed in this region are characterized by deep splits between lineages that coalesce between 0.8 and 2.1 Ma. Unlike other regions at this latitude, the Southwest Mountainous Region was largely unaffected by the Pleistocene glaciations. Genetically isolated populations of these birds could thus be maintained throughout the Pleistocene in these rather stable montane environments. In comparison, we found radically different phylogeographical patterns in populations of the same four species distributed in the adjacent lowland, the Central China region. This region has a distinctly different geological history with dramatic, climate‐induced shifts in vegetation during the Pleistocene. Here, we found a considerably less geographical structure in the genetic variation and a much younger coalescence time (0.3–0.7 Ma). We also found evidence of genetic bottlenecks during the glacial periods and gene flow during the interglacial expansions. We conclude that the high genetic diversity in the Southwest Mountainous Region results from a long‐term in situ diversification within these evolutionary isolated and environment stable montane habitats.