State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.
Sichuan Academy of Forestry, Chengdu, China.
Commun Biol. 2022 Oct 25;5(1):1124. doi: 10.1038/s42003-022-04108-y.
The Hengduan Mountains (HDM) of China are a biodiversity hotspot whose temperate flora and fauna are among the world's richest. However, the origin and evolution of biodiversity in the HDM remain poorly understood, especially in mammals. Given that the HDM shows the highest richness of vole species in the world, we used whole-exome capture sequencing data from the currently most comprehensive sampling of HDM voles to investigate their evolutionary history and diversification patterns. We reconstructed a robust phylogeny and re-estimated divergence times of the HDM voles. We found that all HDM voles could be divided into a western lineage (Volemys, Proedromys, and Neodon) and an eastern lineage (Caryomys and Eothenomys), and the two lineages originated from two migration events from North Eurasia to the HDM approximately 9 Mya. Both vole lineages underwent a significant acceleration of net diversification from 8-5 Mya, which was temporally congruent with the orogeny of the HDM region. We also identified strong intertribal gene flow among the HDM voles and hypothesized that frequent gene flow might have facilitated the speciation burst of the HDM voles. Our study highlights the importance of both environmental and biotic factors in shaping the biodiversity of mammals in mountain ecosystems.
中国横断山区是生物多样性热点地区，其温带动植物群是世界上最丰富的之一。然而，横断山区生物多样性的起源和进化仍知之甚少，特别是在哺乳动物方面。鉴于横断山区显示出世界上最多样化的田鼠物种，我们使用了来自目前最全面的横断山区田鼠采样的全外显子捕获测序数据来研究它们的进化历史和多样化模式。我们重建了一个稳健的系统发育树，并重新估计了横断山区田鼠的分化时间。我们发现，所有横断山区田鼠都可以分为西部谱系（Volemys、Proedromys 和 Neodon）和东部谱系（Caryomys 和 Eothenomys），这两个谱系起源于大约 900 万年前从北欧亚大陆向横断山区的两次迁移事件。两个田鼠谱系都经历了从 800 万到 500 万年前的净多样化的显著加速，这与横断山区的造山运动时间上是一致的。我们还发现横断山区田鼠之间存在强烈的部落间基因流，并假设频繁的基因流可能促进了横断山区田鼠的物种爆发。我们的研究强调了环境和生物因素在塑造山地生态系统中哺乳动物生物多样性方面的重要性。
