三江并流区三种两栖类比较谱系地理学研究

三江并流区的环境异质性明显高于横断山区其它区域。因此，三江并流区高海拔两栖类物种的谱系分化模式、对更新世气候波动的响应以及它们的形成机制可能会不同于横断山区其它区域的两栖类物种，河谷下切与山脉抬升对三江并流区高海拔两栖类物种的隔离效应可能更加强烈，种群历史在气候波动时可能更加稳定。本项目拟通过分析胫腺蛙、腹斑倭蛙和华西雨蛙贡山亚种的遗传变异模式和种群历史来检验以下假设：1)三江并流区高海拔两栖类物种经历片段化分化过程，其遗传结构与低海拔干热河谷强烈对应；2)三江并流区高海拔两栖类物种在更新世气候波动时种群历史保持相对稳定；3)三江并流区高海拔两栖类物种的群体间遗传差异很大，但群体内的遗传多样性很低；4)不同海拔群体间的遗传差异可能会随海拔差异的增加而增加(Isolation By Elevation)。通过对上述假设的检验，本项目将更清晰地揭示三江并流区高海拔两栖类物种的形成与分化机制。

Environmental heterogeneity of the Three Parallel Rivers region is obviously higher than that of other regions of the Hengduan Mountains. Thus, divergence pattern and responses to the Pleistocene climatic oscillations of alpine amphibian species from the Three Parallel Rivers region may differ from that of species from other regions of the Hengduan Mountains, isolation effect of river valleys undercut and mountains uplift on the divergence of alpine amphibians from the Three Parallel Rivers region may be stronger, and historical demography of population may be more stable during climatic oscillations. By investigating the patterns of lineage divergence and historical demographies of Rana shuchinae, Nanorana ventripunctata, and Hyla annectans gongshanensis, this project is going to test for the following four hypotheses: 1) alpine amphibian species from the Three Parallel Rivers region have underwent the process of fragmented divergence and their population structures are strongly consistent with the low-elevational dry hot valleys; 2) alpine amphibian species in the Three Parallel Rivers region retain population stable during the Pleistocene climatic oscillations; 3) genetic difference between populations of alpine amphibian species from the Three Parallel Rivers region is high, and intra-population genetic diversity is low; and 4) vertically genetic divergence between populations at different elevation levels should increase with the increase of elevational difference (Isolation by elevation). By the investigation of these hypotheses, this project will reveal the mechanism of speciation and divergence of alpine amphibian species from the region of Three Parallel Rivers more clearly.