Data from: Using relatedness networks to infer contemporary dispersal: application to the endangered mammal Galemys pyrenaicus

Information about the degree of contemporary dispersal is important when trying to understand how populations interchange individuals and identify the specific barriers that prevent these movements. In the case of endangered species, this can represent crucial information when designing appropriate strategies that favor natural genetic exchange between populations. Here we analyze the parentage relationships between individuals from different localities and use these data to infer dispersal occurred in recent generations. We applied this approach to the Pyrenean desman (Galemys pyrenaicus), a semiaquatic and endangered species endemic to the Iberian Peninsula. We studied this species in four primary rivers in the Iberian Range, where two ancient mitochondrial lineages are separated by a strict contact zone but whose populations are more homogeneous at the genome level, suggesting the existence of complex dispersal patterns. Using next generation sequencing, we obtained 912 SNPs from each sample and estimated relatedness values between them. While relatedness networks were very dense within each river, we found surprisingly few relationships between individuals from different rivers despite their close proximity in some cases, indicating that dispersal between rivers is extremely low compared to dispersal within a single river. In agreement with this, the degree of inbreeding was exceedingly high in most individuals. These data show that relatedness information can be crucial to understand the contemporary dispersal patterns and conservation status of specific populations of endangered species.

在探究种群间个体交换模式、辨识阻碍此类迁移的特定屏障时，当代扩散程度的相关信息至关重要。针对濒危物种而言，这类信息在制定利于种群间自然基因交流的科学保护策略时，堪称核心依据。本研究对不同采样位点个体间的亲缘关系展开分析，并依托此类数据推演近世代的扩散事件。我们将该研究方法应用于比利牛斯麝鼩（Pyrenean desman, *Galemys pyrenaicus*）——一种栖息于伊比利亚半岛的半水生濒危特有物种。我们在伊比利亚山脉的四条主要河流中开展了该物种的调查：此处存在两个古老的线粒体谱系，二者被严格的接触带分隔，但种群在基因组层面的遗传同质化程度更高，这暗示着复杂扩散模式的存在。借助下一代测序（Next Generation Sequencing, NGS）技术，我们从每份样本中获得了912个单核苷酸多态性（Single Nucleotide Polymorphism, SNP）位点，并估算了个体间的亲缘关系值。尽管每条河流内部的亲缘关系网络极为密集，但我们却意外发现，即便部分跨河流的采样点相距较近，不同河流间的个体亲缘关系却极少，这表明相较于单条河流内部的扩散，跨河流的扩散程度极低。与此结论相符的是，绝大多数个体的近交程度极高。本研究数据证实，亲缘关系信息对于解析濒危物种种群的当代扩散模式与保护现状，具有不可替代的关键意义。