Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM 87131, USA.
Mol Ecol. 2011 Oct;20(20):4346-70. doi: 10.1111/j.1365-294X.2011.05226.x. Epub 2011 Sep 15.
Environmental processes govern demography, species movements, community turnover and diversification and yet in many respects these dynamics are still poorly understood at high latitudes. We investigate the combined effects of climate change and geography through time for a widespread Holarctic shrew, Sorex tundrensis. We include a comprehensive suite of closely related outgroup taxa and three independent loci to explore phylogeographic structure and historical demography. We then explore the implications of these findings for other members of boreal communities. The tundra shrew and its sister species, the Tien Shan shrew (Sorex asper), exhibit strong geographic population structure across Siberia and into Beringia illustrating local centres of endemism that correspond to Late Pleistocene refugia. Ecological niche predictions for both current and historical distributions indicate a model of persistence through time despite dramatic climate change. Species tree estimation under a coalescent process suggests that isolation between populations has been maintained across timeframes deeper than the periodicity of Pleistocene glacial cycling. That some species such as the tundra shrew have a history of persistence largely independent of changing climate, whereas other boreal species shifted their ranges in response to climate change, highlights the dynamic processes of community assembly at high latitudes.
环境过程控制着人口动态、物种运动、群落更替和多样化，但在很大程度上，这些动态在高纬度地区仍未得到充分理解。我们通过时间研究了广布的北极鼩鼱（Sorex tundrensis）的气候变化和地理因素的综合影响。我们包括了一套广泛的密切相关的外群分类群和三个独立的基因座，以探索系统地理学结构和历史种群动态。然后，我们探讨了这些发现对其他北方社区成员的影响。苔原鼩鼱及其姊妹种天山鼩鼱（Sorex asper）在西伯利亚和白令海峡表现出强烈的地理种群结构，说明了与晚更新世避难所相对应的地方性特有中心。对当前和历史分布的生态位预测表明，尽管气候变化剧烈，但物种通过时间得以持续存在。在一个合并过程下的种系发生树估计表明，种群之间的隔离在比更新世冰期循环的周期性更深的时间范围内得到了维持。一些物种，如苔原鼩鼱，在很大程度上独立于气候变化而持续存在，而其他北方物种则根据气候变化改变了它们的分布范围，这凸显了高纬度地区群落组装的动态过程。
