Global population structure and demographic history of the grey seal

Although the grey seal Halichoerus grypus is one of the most familiar and intensively studied of all pinniped species, its global population structure remains to be elucidated. Little is also known about how the species as a whole may have historically responded to climate-driven changes in habitat availability and anthropogenic exploitation. We therefore analysed samples from over 1500 individuals collected from 22 colonies spanning the Western and Eastern Atlantic and the Baltic Sea regions, represented by 350bp of the mitochondrial hypervariable region and up to nine microsatellites. Strong population structure was observed at both types of marker, and highly asymmetrical patterns of gene flow were also inferred, with the Orkney islands being identified as a source of emigrants to other areas in the Eastern Atlantic. The Baltic and Eastern Atlantic regions were estimated to have diverged a little over 10,000 years ago, consistent with the last proposed isolation of the Baltic Sea. Ap...尽管灰海豹（Halichoerus grypus）是最广为人知且研究最为深入的鳍足目物种之一，但其全球种群结构仍有待阐明。此外，学界对该物种种群整体在历史上如何响应气候驱动的栖息地可用性变化以及人为开发活动的认知仍较为匮乏。为此，本研究对覆盖大西洋西部、东部及波罗的海海域共22个繁殖种群的1500余份个体样本进行了分析，检测位点包括350bp的线粒体高变区（mitochondrial hypervariable region）以及最多9个微卫星（microsatellites）位点。两类分子标记均检测到显著的种群遗传结构，同时推断出高度不对称的基因流模式，其中奥克尼群岛被确定为向东大西洋其他区域输出迁出个体的源种群。本研究估计波罗的海种群与东大西洋种群的分化时间距今约1万余年，与学界提出的波罗的海末次隔离事件时间相符。Ap...