Past climate change drives current genetic structure of an endangered freshwater mussel species

Historical-to-recent climate change and anthropogenic disturbance affect species distributions and genetic structure. The Rio Grande watershed of the United States and Mexico encompasses ecosystems that are intensively exploited, resulting in substantial degradation of aquatic habitats. While significant anthropogenic disturbances in the Rio Grande are recent, inhospitable conditions for freshwater organisms likely existed prior to such disturbances. A combination of anthropogenic and past climate factors may contribute to current distributions of aquatic fauna in the Rio Grande basin. We used mitochondrial DNA and 18 microsatellite loci to infer evolutionary history and genetic structure of an endangered freshwater mussel, Popenaias popeii, throughout the Rio Grande drainage. We estimated spatial connectivity and gene flow across extant populations of P. popeii and used ecological niche models (ENMs) and approximate Bayesian computation (ABC) to infer its evolutionary history during th...从古至今的气候变化与人为扰动会影响物种的分布格局与遗传结构。美墨两国境内的格兰德河（Rio Grande）流域涵盖了被高强度开发利用的生态系统，进而导致水生栖息地发生严重退化。尽管格兰德河流域的重大人为扰动是近期才出现的，但淡水生物赖以生存的恶劣环境或许早在这类扰动发生前就已存在。人为活动与古气候因素的共同作用，可能塑造了格兰德河盆地当前的水生动物分布格局。本研究借助线粒体DNA（mitochondrial DNA）与18个微卫星位点（microsatellite loci），对分布于整个格兰德河水系的濒危淡水蚌Popenaias popeii的演化历史与遗传结构进行了推断。我们对P. popeii现存种群的空间连通性与基因流进行了估算，并利用生态位模型（ecological niche models, ENMs）与近似贝叶斯计算（approximate Bayesian computation, ABC）推断了其在……时期的演化历史。