The population genetics of urban and rural amphibians in North America

Human land transformation is one of the leading causes of vertebrate population declines. These declines are thought to be partly due to decreased connectivity and habitat loss reducing animal population sizes in disturbed habitats. With time, this can lead to declines in effective population size and genetic diversity which restricts the ability of wildlife to efficiently cope with environmental change through genetic adaptation. However, it is not well understood whether these effects generally hold across taxa. We address this question by repurposing and synthesizing raw microsatellite data from online repositories for 19 amphibian species sampled at 554 georeferenced sites in North America. For each site, we estimated gene diversity, allelic richness, effective population size, and population differentiation. Using binary urban-rural census designations, and continuous measures of human population density, the Human Footprint Index, and impervious surface cover, we tested for genera...人类土地改造是脊椎动物种群衰退的主要驱动因素之一。现有研究推测，此类衰退部分源于连通性下降与栖息地丧失，导致受干扰生境中的动物种群规模缩减。随着时间推移，这一过程将引发有效种群规模（effective population size）与遗传多样性的下降，进而限制野生动物通过遗传适应高效应对环境变化的能力。然而，此类效应是否在所有生物类群中普遍成立，目前仍缺乏充分的认知。为此，本研究重新利用并整合了在线数据库中的原始微卫星（microsatellite）数据，针对北美地区554个地理参考样点采集的19种两栖动物展开分析，以解答上述疑问。针对每个样点，我们分别估算了基因多样性、等位基因丰富度、有效种群规模以及种群分化程度。研究中，我们采用二元城乡人口普查分类标准，以及人类人口密度、人类足迹指数（Human Footprint Index）和不透水面覆盖率等连续型测度指标，对各属类群开展了