Supplementary 2 from Mice as stowaways? Colonization history of Danish striped field mice

Species from the steppe region of Eastern Europe likely colonized Northwestern Europe in connection with agriculture after 6500 BP. The striped field mouse (Apodemus agrarius Pallas, 1783), is a steppe-derived species often found in human crops, that is common on the southern Danish islands of Lolland and Falster, which have been isolated from mainland Europe because approximately10 300–8000 BP. Thus, this species could have been brought in with humans in connection with agriculture, or it could be an earlier natural invader. We sequenced 86 full mitochondrial genomes from the Northwestern range of the striped field mouse, analysed phylogenetic relationships and estimated divergence time. The results supported human-induced colonization of Denmark in the Subatlantic or Subboreal period. A newly discovered population from Central Jutland in Denmark diverged from Falster approximately 100–670 years ago, again favouring human introduction. One individual from Sweden turned out to be a recent introduction from Central Jutland.

东欧草原地带的物种，大概率在距今6500年之后伴随农业活动，定居至西北欧地区。黑线姬鼠（Apodemus agrarius Pallas, 1783）为草原起源物种，常出没于人类农田，广泛分布于丹麦南部的洛兰岛（Lolland）与法尔斯特岛（Falster）——这两座岛屿自距今约10300至8000年起便与欧洲大陆相互隔绝。据此推测，该物种要么是随人类农业活动一同被引入当地，要么是更早的自然入侵物种。本研究对黑线姬鼠分布范围西北部的86个完整线粒体基因组（mitochondrial genomes）进行了测序，分析其系统发育关系并估算了分化时间。研究结果支持该物种在亚大西洋期或亚北方期经由人类活动介导定居丹麦的结论。丹麦日德兰半岛中部新发现的种群，与法尔斯特岛种群的分化时间约为距今100至670年，这一结果进一步支持人类引入的假说。另有一只采自瑞典的个体，经分析证实为近期来自日德兰半岛中部的引入种群。