Postglacial climate changes and rise of three ecotypes of harbor porpoises, Phocoena phocoena, in western Palearctic waters

Despite no obvious barriers to gene flow in the marine realm, environmental variation and ecological specializations can lead to genetic differentiation in highly mobile predators. Here, we investigated the genetic structure of the harbor porpoise over the entire species distribution range in western Palearctic waters. Combined analyses of ten microsatellite loci and a 5,085 bases-pairs portion of the mitochondrial genome revealed the existence of three ecotypes, equally divergent at the mitochondrial genome, distributed in the Black Sea, the European continental shelf waters, and a previously overlooked ecotype in the upwelling zones of Iberia and Mauritania. Historical demographic inferences using Approximate Bayesian Computation (ABC) suggest that these ecotypes diverged during the Last Glacial Maximum (~23–19 kilo-years ago, kyrBP). ABC supports the hypothesis that the Black Sea and upwelling ecotypes share a more recent common ancestor (~14 kyrBP) than either does with the European...

尽管海洋环境中不存在明显的基因流障碍，但环境异质性与生态特化仍可导致高度移动性捕食者种群产生遗传分化。本研究针对西古北界(western Palearctic)水域内港湾鼠海豚(Harbor Porpoise)的完整分布范围，对其种群遗传结构展开了系统调查。本研究结合10个微卫星位点(microsatellite loci)与一段长5085碱基对的线粒体基因组(mitochondrial genome)序列开展联合分析，结果显示存在3种在线粒体基因组层面遗传分化程度相当的生态型(ecotypes)，其分布范围分别为黑海、欧洲大陆架水域，以及此前未被关注的伊比利亚半岛与毛里塔尼亚上升流区生态型。采用近似贝叶斯计算(Approximate Bayesian Computation, ABC)开展的历史种群动态推断结果表明，这些生态型的分化发生于末次冰盛期（约2.3万至1.9万年前，kyrBP）。近似贝叶斯计算支持如下假说：黑海生态型与上升流区生态型的最近共同祖先分化时间约为1.4万年前（14 kyrBP），早于二者分别与欧洲...