Elucidating the factors underlying the origin and maintenance of genetic variation among populations is crucial for our understanding of their ecology and evolution, and also to help identify conservation priorities. While intrinsic movement has been hypothesized as the major determinant of population genetic structuring in abundant vagile species, growing evidence indicates that vagility does not always predict genetic differentiation. However, identifying the determinants of genetic structuring can be challenging, and these are largely unknown for most vagile species. Although, in principle, levels of gene flow can be inferred from neutral allele frequency divergence among populations, underlying assumptions may be unrealistic. Moreover, molecular studies have suggested that contemporary gene flow has often not overridden historical influences on population genetic structure, which indicates potential inadequacies of any interpretations that fail to consider the influence of history in shaping that structure. This exhaustive review of the theoretical and empirical literature investigates the determinants of population genetic differentiation using seabirds as a model system for vagile taxa. Seabirds provide a tractable group within which to identify the determinants of genetic differentiation, given their widespread distribution in marine habitats and an abundance of ecological and genetic studies conducted on this group. Herein we evaluate mitochondrial DNA (mtDNA) variation in 73 seabird species. Lack of mutation–drift equilibrium observed in 19% of species coincided with lower estimates of genetic differentiation, suggesting that dynamic demographic histories can often lead to erroneous interpretations of contemporary gene flow, even in vagile species. Presence of land across the species sampling range, or sampling of breeding colonies representing ice‐free Pleistocene refuge zones, appear to be associated with genetic differentiation in Tropical and Southern Temperate species, respectively, indicating that long‐term barriers and persistence of populations are important for their genetic structuring. Conversely, biotic factors commonly considered to influence population genetic structure, such as spatial segregation during foraging, were inconsistently associated with population genetic differentiation. In light of these results, we recommend that genetic studies should consider potential historical events when identifying determinants of genetic differentiation among populations to avoid overestimating the role of contemporary factors, even for highly vagile taxa.

中文翻译：

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变异物种种群间遗传分化的识别机制：历史因素主导海鸟的遗传分化

阐明种群间遗传变异起源和维持的潜在因素对于我们了解其生态和进化至关重要，也有助于确定保护优先事项。虽然内在运动已被假设为丰富的可变性物种中种群遗传结构的主要决定因素，但越来越多的证据表明可变性并不总是能预测遗传分化。然而，确定遗传结构的决定因素可能具有挑战性，而这些对于大多数变异物种来说在很大程度上是未知的。尽管原则上可以从种群之间的中性等位基因频率差异中推断出基因流动的水平，但潜在的假设可能不切实际。而且，分子研究表明，当代基因流动往往没有推翻对种群遗传结构的历史影响，这表明任何未考虑历史对塑造该结构的影响的解释都有潜在的不足之处。这篇对理论和经验文献的详尽回顾研究了使用海鸟作为可变分类群模型系统的种群遗传分化的决定因素。鉴于海鸟在海洋栖息地的广泛分布以及对该群体进行的大量生态和遗传研究，海鸟提供了一个易于处理的群体，可以在其中确定遗传分化的决定因素。在此，我们评估了 73 种海鸟物种的线粒体 DNA (mtDNA) 变异。在 19% 的物种中观察到缺乏突变-漂移平衡，同时对遗传分化的估计值较低，这表明动态人口历史往往会导致对当代基因流的错误解释，即使是在不稳定的物种中也是如此。物种采样范围内土地的存在，或代表无冰更新世避难区的繁殖群的采样，似乎分别与热带和南温带物种的遗传分化有关，表明长期障碍和种群的持久性很重要因为他们的基因结构。相反，通常认为影响种群遗传结构的生物因素，例如觅食过程中的空间隔离，与种群遗传分化不一致。鉴于这些结果，