Data from: Invasion genetics of the introduced black rat (Rattus rattus) in Senegal, West Africa

An understanding of the evolutionary history and dynamics of invasive species is required for the construction of predictive models of future spread, and the design of biological management measures. The black rat (Rattus rattus) is a major vertebrate invader with a worldwide distribution. Despite the severe ecological, economic and health impacts of this species, its evolutionary history has been little studied. We carried out extensive specimen sampling in Senegal, West Africa, and used microsatellite markers to describe the pattern and processes of invasion in this large continental area. The genetic data obtained were combined with historical knowledge concerning the presence of this species in Senegal. Data were analyzed by a combination of Bayesian clustering and approximate Bayesian computation methods. The invasion pathways closely paralleled the history of human trade routes in Senegal. In several places, we detected the occurrence of multiple introductions from genetically different sources. Long-distance migration between towns and villages was also observed. Our findings suggest that genetic bottlenecks and admixture have played a major role in shaping the genetics of invasive black rats. These two processes may generate genetic novelty and favor rapid evolution along the invasion pathways.

要构建外来物种未来扩散的预测模型、设计生物防控措施，需先明晰入侵物种的演化历史与动态过程。黑家鼠（Rattus rattus）是全球分布的主要脊椎动物入侵物种。尽管该物种已造成严重的生态、经济与健康危害，但其演化历史却极少被系统研究。我们在西非塞内加尔开展了大范围标本采样，利用微卫星标记（microsatellite markers）解析了这片广袤大陆区域内的入侵模式与入侵进程。将获取的遗传数据与塞内加尔境内该物种的历史分布记录相结合，我们采用贝叶斯聚类与近似贝叶斯计算（approximate Bayesian computation）的组合分析方法对数据进行处理。研究结果显示，其入侵路径与塞内加尔境内人类贸易路线的历史高度契合。在多个采样位点，我们检测到来自不同遗传来源的多次独立引入事件，同时还观察到城镇与乡村间存在长距离迁移现象。本研究表明，遗传瓶颈（genetic bottleneck）与遗传混合（admixture）在塑造入侵性黑家鼠的遗传特征中发挥了核心作用，这两种过程或可产生新的遗传变异，并助力其沿入侵路径实现快速演化。