EAPSI: Investigating Historical Changes in Montane River Systems and Their Roles in Species Diversification

EAPSI：调查山地河流系统的历史变化及其在物种多样化中的作用

• 批准号: 1714006
• 负责人: Kai Wang
• 金额: $ 0.54万
• 依托单位: Wang Kai
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1714006&HistoricalAwards=false
• 关键词: EAPSI; Investigating; Historical; Changes; Montane

Ancient geological events such as changes in river drainages and the formation of mountain ranges can have profound impacts on the genetic structure and evolution of organisms. By analyzing the genetic diversity of different populations of organisms across complex environments, inferences can be made about the timing and distribution of such historical processes and their impacts on species evolution. The Hengduan Mountain Region (HMR) is positioned at the transition zone between the Tibetan Plateau and lowland southwest China. This region is unique in having repeated, parallel, montane river systems that run across dramatic elevational and environmental gradients. Studies have shown that the major rivers of the region (Mekong, Salween, and Yangtze) have experienced significant changes in drainage patterns and flow directions in the past due to the continental collisions between Eurasia and India and the subsequent formation of the Tibetan Plateau, and these geological events have impacted genetic structures among some aquatic animals and plants in the region. However, the timing and geographic scope of changes in river topology remain poorly understood, and nothing is known to date about the impact of such events on the evolution of terrestrial vertebrates. Lizard species of the genus Japalura are recognized to be associated closely with habitats along river systems in the HMR. With many species endemic to the HMR, the group of terrestrial lizards is well suited for investigating the impact of historical geologic- and environmental-changes on population and species diversification in the region. In collaboration with Dr. Jing Che from the Chinese Academy of Sciences, this research will employ modern molecular techniques to the genetic data of endemic lizards in the HMR. Through field-based surveys of species diversity of lizards and lab-based studies of genetic diversity of the focal species group across the HMR, this research not only will promote biodiversity and conservation studies of the focal species group in a fragile ecosystem, but also, it will further our knowledge of the historical importance of the formation of the Tibetan Plateau for changes in river systems as well as for vertebrate diversification in the HMR.During the research period in China, fieldwork will be conducted in targeted valley habitats along the three major rivers (Mekong, Salween, and Yangtze) in the Hengduan Mountain Region (HMR) of China to increase available taxonomic and geographic sampling of focal lizard species in the genus Japalura. Combined with samples available already at the host institution in China, genomic DNA will be extracted from tissue samples, and target genes (mitochondrial and nuclear) will be amplified and sequenced at the host institute in China. Phylogenetic approaches will be employed to study population genetic and biogeographic patterns, and estimate the timing of lineage divergence, among focal lizard species across the HMR. The results will be used to formulate biogeographical hypotheses concerning the role that historical changes in river system and formation of mountain ranges played in the vertebrate diversification around the Tibetan Plateau.The award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the Chinese Ministry of Science and Technology.

河流水系的变化和山脉的形成等古代地质事件可能对生物的遗传结构和进化产生深远影响。通过分析复杂环境中不同生物种群的遗传多样性，可以推断这些历史过程的时间和分布及其对物种进化的影响。横断山区位于青藏高原和西南低地的过渡地带。该地区的独特之处在于具有重复、平行的山区河流系统，这些河流系统跨越巨大的海拔和环境梯度。研究表明，该地区的主要河流（湄公河，萨尔温江和长江）在过去由于欧亚大陆和印度之间的大陆碰撞以及随后的青藏高原的形成而经历了排水模式和流向的重大变化，这些地质事件影响了该地区一些水生动物和植物的遗传结构。然而，河流拓扑结构变化的时间和地理范围仍然知之甚少，迄今为止，关于这些事件对陆生脊椎动物进化的影响也一无所知。日本蜥属的蜥蜴种被认为与HMR中沿着水系的栖息地密切相关。由于HMR有许多特有物种，这组陆生蜥蜴非常适合调查历史地质和环境变化对该地区人口和物种多样性的影响。与中国科学院的Jing Che博士合作，这项研究将采用现代分子技术来研究HMR特有蜥蜴的遗传数据。通过野外蜥蜴物种多样性调查和实验室重点种组遗传多样性研究，本研究不仅将促进脆弱生态系统中重点种组的生物多样性和保护研究，它将进一步加深我们对青藏高原形成对河流系统变化以及脊椎动物多样化的历史重要性的认识在中国的研究期间，将在中国横断山区（HMR）三大河流（湄公河、萨尔温江和长江）沿线沿着的目标山谷栖息地进行实地调查，以增加日本蜥属重点蜥蜴物种的分类学和地理学样本。结合中国主办机构已有的样本，将从组织样本中提取基因组DNA，并在中国主办机构扩增和测序靶基因（线粒体和核）。系统发育的方法将被用来研究人口的遗传和地理模式，并估计谱系分歧的时间，在整个HMR的焦点蜥蜴物种。该研究成果将被用于建立有关青藏高原地区河流系统的历史变迁和山脉形成在脊椎动物多样性中所起作用的地理学假说。该研究是由美国国家科学基金会和中国科技部共同资助的东亚和太平洋夏季研究所项目的一部分。