What determines the level of genetic diversity of a species remains one of the enduring problems of population genetics. Because neutral diversity depends upon the product of the effective population size and mutation rate, there is an expectation that diversity should be correlated to measures of census population size. This correlation is often observed for nuclear but not for mitochondrial DNA. Here, we revisit the question of whether mitochondrial DNA sequence diversity is correlated to census population size by compiling the largest data set to date, using 639 mammalian species. In a multiple regression, we find that nucleotide diversity is significantly correlated to both range size and mass-specific metabolic rate, but not a variety of other factors. We also find that a measure of the effective population size, the ratio of nonsynonymous to synonymous diversity, is also significantly negatively correlated to both range size and mass-specific metabolic rate. These results together suggest that species with larger ranges have larger effective population sizes. The slope of the relationship between diversity and range is such that doubling the range increases diversity by 12–20%, providing one of the first quantifications of the relationship between diversity and the census population size.

中文翻译：

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哺乳动物线粒体 DNA 序列多样性：有效种群规模与人口普查种群规模之间的相关性

决定物种遗传多样性水平的因素仍然是种群遗传学的持久问题之一。由于中性多样性取决于有效种群规模和突变率的乘积，因此期望多样性应与人口普查种群规模的度量相关联。这种相关性经常在核 DNA 中观察到，但在线粒体 DNA 中却没有。在这里，我们通过编译迄今为止最大的数据集，使用 639 种哺乳动物重新审视线粒体 DNA 序列多样性是否与人口普查人口规模相关的问题。在多元回归中，我们发现核苷酸多样性与范围大小和质量特异性代谢率显着相关，但与其他各种因素无关。我们还发现，有效人口规模的衡量标准，非同义多样性与同义多样性的比率也与范围大小和质量特异性代谢率显着负相关。这些结果共同表明，分布范围较大的物种具有较大的有效种群规模。多样性与范围之间关系的斜率使得范围加倍会使多样性增加 12-20%，这提供了多样性与人口普查人口规模之间关系的第一个量化指标。