Population structure over a broad spatial scale driven by non-anthropogenic factors in a wide-ranging migratory mammal, Alaskan caribou

Wide-ranging mammals face significant conservation threats, and knowledge of the spatial scale of population structure and its drivers is needed to understand processes that maintain diversity in these species. We analysed DNA from 655 Alaskan caribou (Rangifer tarandus granti) from 20 herds that vary in population size, used 19 microsatellite loci to document genetic diversity and differentiation in Alaskan caribou, and examined the extent to which genetic differentiation was associated with hypothesized drivers of population subdivision including landscape features, population size and ecotype. We found that Alaskan caribou are subdivided into two hierarchically structured clusters: one group on the Alaska Peninsula containing discrete herds and one large group on the Mainland lacking differentiation between many herds. Population size, geographic distance, migratory ecotype and the Kvichak River at the nexus of the Alaska Peninsula were associated with genetic differentiation. Contra...

广布型哺乳动物面临严峻的保护威胁，而了解种群结构（population structure）的空间尺度及其驱动因素，对于阐明维系这些物种多样性的过程至关重要。我们分析了来自20个种群规模各异的阿拉斯加驯鹿（Rangifer tarandus granti）种群的655份DNA样本，利用19个微卫星位点（microsatellite loci）记录阿拉斯加驯鹿的遗传多样性（genetic diversity）与遗传分化（genetic differentiation）情况，并考察了遗传分化与假设的种群分化驱动因素（包括景观特征、种群规模及生态型（ecotype））之间的关联程度。研究发现，阿拉斯加驯鹿可划分为两个具有层级结构聚类群（hierarchically structured clusters）的类群：其一为阿拉斯加半岛上包含多个离散种群的类群，其二为阿拉斯加本土上多数种群间缺乏分化的大型类群。种群规模、地理距离、迁徙生态型（migratory ecotype）以及位于阿拉斯加半岛枢纽位置的克维查克河（Kvichak River）均与遗传分化存在关联。Contra...