Department of Animal Behaviour, Bielefeld University, 33501, Bielefeld, Germany.
Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, EH9 3FL, United Kingdom.
Sci Rep. 2020 Mar 20;10(1):5089. doi: 10.1038/s41598-020-61560-8.
Understanding the effects of human exploitation on the genetic composition of wild populations is important for predicting species persistence and adaptive potential. We therefore investigated the genetic legacy of large-scale commercial harvesting by reconstructing, on a global scale, the recent demographic history of the Antarctic fur seal (Arctocephalus gazella), a species that was hunted to the brink of extinction by 18 and 19 century sealers. Molecular genetic data from over 2,000 individuals sampled from all eight major breeding locations across the species' circumpolar geographic distribution, show that at least four relict populations around Antarctica survived commercial hunting. Coalescent simulations suggest that all of these populations experienced severe bottlenecks down to effective population sizes of around 150-200. Nevertheless, comparably high levels of neutral genetic variability were retained as these declines are unlikely to have been strong enough to deplete allelic richness by more than around 15%. These findings suggest that even dramatic short-term declines need not necessarily result in major losses of diversity, and explain the apparent contradiction between the high genetic diversity of this species and its extreme exploitation history.
了解人类开发活动对野生种群遗传组成的影响对于预测物种的持续存在和适应潜力非常重要。因此，我们通过重建全球范围内的南极软毛海豹（Arctocephalus gazella）的近期种群历史，来研究大规模商业捕捞的遗传遗产。该物种在 19 世纪和 18 世纪被海豹猎人捕猎到濒临灭绝的边缘。来自该物种环极地理分布的所有 8 个主要繁殖地的 2000 多个个体的分子遗传数据表明，至少有四个南极周围的遗留种群在商业捕捞中幸存下来。并通过合并模拟表明，所有这些种群都经历了严重的瓶颈，有效种群大小降至约 150-200 个。然而，保留了相当高水平的中性遗传变异，因为这些下降不太可能足以使等位基因丰富度减少超过约 15%。这些发现表明，即使是短期的剧烈下降也不一定会导致多样性的重大损失，并解释了该物种的高遗传多样性与其极端开发历史之间的明显矛盾。
