Data from: Genetic relationships of extant brown bears (Ursus arctos) and polar bears (Ursus maritimus)

Polar bears (Ursus maritimus) and brown bears (Ursus arctos) are closely related species for which extensive mitochondrial and nuclear phylogenetic genetic comparisons have been made. We used previously-published genotype data for 8 microsatellite DNA loci from 930 brown bears in 19 populations and 473 polar bears in 16 populations to compare the population genetic relationships of extant populations of the species. Genetic distances (Nei standard distance = 1.157), the proportion of private alleles (52% of alleles are not shared by the species), and Bayesian cluster analysis are consistent with morphological and life history characteristics that distinguish polar bears and brown bears as different species with little or no gene flow among extant populations.

北极熊（Ursus maritimus）与棕熊（Ursus arctos）是亲缘关系密切的物种，二者已开展过多项大规模线粒体与核基因组的系统发育遗传学比较研究。本研究利用已发表的基因型数据，该数据覆盖19个种群共930只棕熊、16个种群共473只北极熊的8个微卫星DNA（microsatellite DNA）位点信息，用于对比两个物实现有种群的群体遗传关系。遗传距离（奈氏标准遗传距离=1.157）、私有等位基因占比（52%的等位基因未在两个物种间共享）以及贝叶斯聚类分析结果，均与区分北极熊与棕熊为不同物种的形态学和生活史特征相一致，表明二者现存种群间几乎不存在基因交流或基因交流程度极低。