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.

西欧的高海拔山脉对欧洲从冰川避难所开展的生物再拓殖（biotic recolonisation）过程产生了深远影响。阿尔卑斯山脉便是一个尤为引人关注的案例，因其对绝大多数生物类群的扩散构成了绝对屏障，阻碍了来自意大利北部多处冰川避难所的再拓殖进程。本研究旨在探究阿尔卑斯山脉对欧洲林蛙（Rana temporaria）谱系地理学（phylogeography）历史的影响。基于采自瑞士的部分细胞色素b（cytochrome b）与COXI序列，本研究发现了两条大致分布于阿尔卑斯山脊南北两侧的线粒体谱系，二者的接触带位于瑞士东部与西部地区。北部单倍群（haplogroup）隶属于此前已鉴定的西欧单倍群，而南部单倍群则为瑞士所特有。研究结果显示，这两条谱系的分化时间约为11万年前，恰好处于末次冰期的起始阶段，这表明它们源自不同的冰川避难所。系统发育学（phylogenetics）分析表明，北部与南部单倍群分别通过跨阿尔卑斯与环阿尔卑斯的扩散路径，从意大利北部至少两处独立的冰川避难所拓殖至瑞士境内。本研究结果揭示了高海拔山脉形成的半渗透屏障，如何塑造出中欧阿尔卑斯山脉区域复杂的生物再拓殖历史。