Comparative multi-locus assessment of modern Asian newts (<i>Cynops</i>, <i>Paramesotriton</i>, and <i>Pachytriton</i>: Salamandridae) in southern China suggests a shared biogeographic history
Zhi-Yong Yuan, 中国科学院昆明动物研究所遗传资源与进化国家重点实验室, 云南省高黎贡山生物多样性与生态安全重点实验室, 云南 昆明 650223, 中国, Yunke Wu, Fang Yan, Robert W. Murphy, Theodore J. Papenfuss, David B. Wake, Ya‐Ping Zhang, Jing Che, 西南大学生命科学学院淡水鱼繁殖与发育教育部重点实验室, 重庆 400715, 中国, 云南大学生命科学学院, 云南 昆明 650091, 中国
Abstract
Evolutionary biologists are always interested in deciphering the geographic context of diversification, therefore they introduced the concept of comparative phylogeography, which helps to identify common mechanisms that contribute to shared genetic structures among organisms from the same region. Here, we used multi-locus genetic data along with environmental data to investigate shared phylogeographic patterns among three Asian-endemic newt genera, <i>Cynops</i>, <i>Paramesotriton</i> and <i>Pachytriton</i>, which occurred in montane/submontane streams or ponds in southern China. Our 222 samples from 78 localities covered the entire range of the three genera and represented the largest dataset of this group to date. We reconstructed matrilineal genealogies from two protein-coding, mitochondrial genes, and gene network from two nuclear genes. We also estimated divergence times of major cladogenetic events and used occurrence data to evaluate niche difference and similarity between lineages. Our results revealed a common basal split in all three genera that corresponds to the separation of two geographic terrains of southern China. Those ancient divergence occurred during middle to late Miocene and likely correlate with paleoclimatic fluctuations caused by the uplift of the Qinghai-Xizang (Tibet) Plateau (QTP). Particularly, the strengthening and weakening of Asian summer monsoons during the Miocene may have profoundly impacted southern China and led to repeatedly vicariance in those newts. However, despite differences in realized niches between lineages, there is no evidence for divergence of fundamental niches. Preservation of old newt matriline lineages in mountains of southern China suggests that the region acts as both museums and cradles of speciation. Based on those results, we advocate a multi-pronged protection strategy for newts in the three genera.