Data from: European common frog (Rana temporaria) recolonised Switzerland from multiple glacial refugia in northern Italy via trans- and circum-Alpine routes

The high mountain ranges of western Europe had a profound effect on the biotic recolonisation of Europe from glacial refugia. The Alps present a particularly interesting case because they form an absolute barrier to dispersal for most taxa, obstructing recolonisation from multiple refugia in northern Italy. Here we investigate the effect of the European Alps on the phylogeographic history of the European common frog Rana temporaria. Based on partial cytochrome b and COXI sequences from Switzerland, we find two mitochondrial lineages roughly north and south of the alpine ridge, with contact zones between them in eastern and western Switzerland. The northern haplogroup falls within the previously identified western European haplogroup, while the southern haplogroup is unique to Switzerland. We find that the lineages diverged ~110 kya, at approximately the onset of the last glacial glaciation; this indicates that they are from different glacial refugia. Phylogenetic analyses suggest that the northern and southern haplogroups colonised Switzerland via trans- and circum-alpine routes from at least two separate refugia in northern Italy. Our results illustrate how a complex recolonisation history of the central European Alps can arise from the semi-permeable barrier created by high mountains.

西欧高海拔山脉对欧洲从冰期避难所（glacial refugia）启动的生物再定居过程产生了深远影响。阿尔卑斯山脉堪称极具代表性的研究案例，其对绝大多数类群的扩散构成绝对屏障，阻碍了来自意大利北部多处避难所的种群再定居。本研究探究了阿尔卑斯山脉对欧洲林蛙Rana temporaria的系统地理学（phylogeography）历史的影响。基于瑞士境内获取的部分细胞色素b（cytochrome b）与细胞色素氧化酶亚基I（COXI）序列数据，我们发现阿尔卑斯山脊南北两侧大致各存在一个线粒体谱系（mitochondrial lineages），二者的接触带分布于瑞士东部与西部。北部单倍群（haplogroup）隶属于此前已鉴定的西欧单倍群，而南部单倍群为瑞士特有类群。我们测算得到两类谱系的分化时间约为11万年前，正值末次冰期的起始阶段，这表明它们源自不同的冰期避难所。系统发育分析显示，北部与南部单倍群分别通过跨阿尔卑斯与环阿尔卑斯路线，从意大利北部至少两处独立的避难所迁入瑞士境内。本研究结果阐明了高海拔山脉形成的半透性屏障，如何塑造了中欧阿尔卑斯区域复杂的种群再定居历史。