Genetic structure in the European endemic seabird, Phalacrocorax aristotelis, shaped by a complex interaction of historical and contemporary, physical and nonphysical drivers
Genetic structure in the European endemic seabird, Phalacrocorax aristotelis, shaped by a complex interaction of historical and contemporary, physical and nonphysical drivers
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欧洲特有海鸟 Phalacrocorax aristotelis 的遗传结构是由历史与当代、物理与非物理驱动因素的复杂相互作用塑造的
作者：
E. Thanou;S. Sponza;E. Nelson;A. Perry;S. Wanless;F. Daunt;S. Cavers
由于阻止扩散的物质或非物质障碍，地理上分离的种群往往不太容易通过基因流动联系在一起，这可能导致遗传结构。在这种情况下，海鸟等高流动性生物很有趣，因为物理屏障的微小影响意味着非物理屏障可能相对更重要。在这里，我们使用微卫星和线粒体数据来探索欧洲特有海鸟Phalacrocorax aristotelis的大西洋和地中海种群的遗传结构和系统地理，并确定它们多样化的主要驱动因素。对线粒体标记的分析揭示了北大西洋、西班牙/科西嘉和东地中海种群的三个系统发育谱系，显然是在更新世之后范围扩大的碎片化过程中产生的。这些历史碎片化的痕迹在微卫星标记估计的遗传结构中也很明显，尽管在相邻种群之间存在着显著的当代基因流动。较强的遗传结构可能是由景观、亲缘关系和当地适应所促进的，在遥远的种群和那些被物理和生态屏障隔开的种群中发现了更强的遗传结构。这项研究强调了更新世气候变化对沙格氏海鸟种群的持久影响，特别是在地中海盆地，并提出了神秘的北部避难所以及已知的南部避难所对欧洲海鸟遗传结构的作用。最后，它概述了当代生态障碍和行为特征如何维持种群分化，尽管极端环境条件(例如人口崩溃)引发了远距离扩散。
Geographically separated populations tend to be less connected by gene flow, as a result of physical or nonphysical barriers preventing dispersal, and this can lead to genetic structure. In this context, highly mobile organisms such as seabirds are interesting because the small effect of physical barriers means nonphysical ones may be relatively more important. Here, we use microsatellite and mitochondrial data to explore the genetic structure and phylogeography of Atlantic and Mediterranean populations of a European endemic seabird, the European shag, Phalacrocorax aristotelis, and identify the primary drivers of their diversification. Analyses of mitochondrial markers revealed three phylogenetic lineages grouping the North Atlantic, Spanish/Corsican and eastern Mediterranean populations, apparently arising from fragmentation during the Pleistocene followed by range expansion. These traces of historical fragmentation were also evident in the genetic structure estimated by microsatellite markers, despite significant contemporary gene flow among adjacent populations. Stronger genetic structure, probably promoted by landscape, philopatry and local adaptation, was found among distant populations and those separated by physical and ecological barriers. This study highlights the enduring effect of Pleistocene climatic changes on shag populations, especially within the Mediterranean Basin, and suggests a role for cryptic northern refugia, as well as known southern refugia, on the genetic structure of European seabirds. Finally, it outlines how contemporary ecological barriers and behavioural traits may maintain population divergence, despite long‐distance dispersal triggered by extreme environmental conditions (e.g. population crashes).