Data from: Spatiotemporal diversification of the true frogs (Genus Rana): a historical framework for a widely studied group of model organisms

True frogs of the genus Rana are widely used as model organisms in studies of development, genetics, physiology, ecology, behavior, and evolution. Comparative studies among the more than 100 species of Rana rely on an understanding of the evolutionary history and patterns of diversification of the group. We estimate a well-resolved, time-calibrated phylogeny from sequences of six nuclear and three mitochondrial loci sampled from most species of Rana, and use that phylogeny to clarify the group's diversification and global biogeography. Our analyses consistently support an "Out of Asia" pattern with two independent dispersals of Rana from East Asia to North America via Beringian land bridges. The more species-rich lineage of New World Rana appears to have experienced a rapid radiation following its colonization of the New World, especially with its expansion into montane and tropical areas of Mexico, Central America, and South America. In contrast, Old World Rana exhibit different trajectories of diversification; diversification in the Old World began very slowly and later underwent a distinct increase in speciation rate around 29–18 Ma. Net diversification is associated with environmental changes and especially intensive tectonic movements along the Asian margin from the Oligocene to early Miocene. Our phylogeny further suggests that previous classifications were misled by morphological homoplasy and plesiomorphic color patterns, as well as a reliance primarily on mitochondrial genes. We provide a phylogenetic taxonomy based on analyses of multiple nuclear and mitochondrial gene loci.

蛙属（Rana）的真蛙类群被广泛用作模式生物，应用于发育学、遗传学、生理学、生态学、行为学及演化生物学的研究中。针对蛙属100余个物种的比较研究，有赖于对该类群演化历史与分化模式的深入认知。本研究从绝大多数蛙属物种中采集了6个核基因座与3个线粒体基因座的序列，构建了解析度良好且经过时间校准的系统发育树，并依托该树阐明了该类群的分化模式与全球生物地理分布格局。本研究的分析结果一致支持“走出亚洲（Out of Asia）”演化模式：蛙属曾通过白令陆桥（Beringian land bridges），两次独立地从东亚扩散至北美大陆。新大陆蛙属中物种更为丰富的演化支，在成功定居新大陆后经历了快速辐射演化，尤其是在向墨西哥、中美洲以及南美洲的山地与热带区域扩张的过程中。与之相对，旧大陆蛙属的分化轨迹则截然不同：旧大陆蛙属的分化进程最初极为缓慢，直至约2900万至1800万年前，其物种形成速率才出现显著提升。净分化速率与环境变化密切相关，尤其与渐新世（Oligocene）至中新世（Miocene）早期亚洲边缘地带的强烈构造活动存在关联。本研究构建的系统发育树进一步表明，此前的分类系统因受到形态同塑性（morphological homoplasy）、祖征性体色模式以及过度依赖线粒体基因的误导而存在偏差。本研究基于多套核基因与线粒体基因座的分析结果，提出了全新的蛙属系统发育分类体系。