Effects of insularity on genetic diversity within and among natural populations

We conducted a review of genetic diversity (GD) within and among populations in relation to categorical population size and isolation (together “insularity”). Using populations from within the same studies, we were able to control for between-study variation in methodology, as well as demographic and life histories. Contradictory to typical expectations, insularity had relatively minor effects on GD within and among population, which points to the more important roles of other factors in shaping evolutionary processes. Such effects of insularity were sometimes seen – particularly in systems (i.e. studies) where GD was already high overall. That is, insularity influenced GD in a study system when GD was high even in non-insular populations of the same system – suggesting an important role for the “scope” of influences on GD. These conclusions were more robust for within - population GD than among - population GD, although a number of biases might underlie this difference. Overall, our fi...我们开展了一项综述研究，旨在探究种群内与种群间的遗传多样性（genetic diversity，GD）与按类别划分的种群大小及隔离程度的关联，二者统称为"岛屿性（insularity）"。我们选取同一研究中的种群作为分析样本，得以控制不同研究间在实验方法、种群统计学特征与生活史特征上的差异。与传统学术预期相悖的是，岛屿性对种群内及种群间的遗传多样性仅存在相对微弱的影响，这表明其他因素在调控进化进程中发挥着更为关键的作用。这类岛屿性的影响仅在部分研究体系中有所体现，尤其是在整体遗传多样性本就较高的研究体系中。换言之，当某一研究体系内非岛屿性种群的遗传多样性本就处于较高水平时，岛屿性才会对该体系的遗传多样性产生影响，这提示遗传多样性的影响"范围"是一项关键影响因素。相较于种群间遗传多样性的分析结果，我们针对种群内遗传多样性得出的结论更为稳健，不过这一差异背后可能存在多种偏倚因素。总体而言，我们的[原文截断]