基于生态位模型与分子系统地理学的四川亚洲黑熊亚种分化机制研究

Subspecies are populations of a species with genetic adaptive features to particular environment in the evolution and have been widely used in the conservation and management of endangered species. Molecular biology can be used to identify genetic divergence of subspecies and track the phylogeny of populations. Over the past decade, combining ecological niche model and molecular phylogeography to study the role of niche divergence in speciation has drawn widely attention in the context of biogeography and conservation biology, however, very few similar research has been reported in China. This project will take the two subspecies of Asiatic black bear (Ursus thibetanus thibetanus and U. t. mupinessis) in Sichuan Province as an example, to assess the suitability and connectivity of habitat using ecological niche model, to determine the genetic differences between populations and time of genetic divergence using analysis of mitochondrial DNA fragment, to further analyze the relationship between genetic divergence and niche divergence, and to explore the evolutionary history of populations at spatial and temporal scale and the mechanism of speciation at intraspecific level.A systematic conservation plan for wild populations of black bear considering the genectic diversity, habitat suitability, and threats will define the unit for the management of the species and enhance the effective conservation of these populations in Sichuan Province. The framework of the methodology established by the project which combines ecological biogeography with historical biogeography can also provide new ideas for research and conservation of other endangered species.

亚种是种群在进化过程中对特定生态环境的遗传适应特征的表现，分子遗传学技术可用来鉴别亚种的遗传差异以及追踪种群的系统进化关系。近年来，将生态位模型与分子系统地理学研究技术结合起来，研究生态位分化在物种形成中的作用，开始受到相关研究工作者的关注。本研究以四川省两个黑熊亚种（Ursus thibetanus thibetanus以及U. t. mupinessis）为研究对象，利用生态位模型评估亚种的栖息地适宜性和连通性，利用线粒体DNA片段分析种群间的遗传差异并确定种群分化时间，分析黑熊亚种遗传分化与生态位分化的关系，从种内水平上探索种群进化的时空历程和亚种形成机制，确定黑熊的遗传保护管理单元，制定系统的保护规划，以促进黑熊野生种群的有效保护。本研究将生态生物地理学与历史生物地理学结合起来，所形成的方法框架也可以为其他的濒危物种的研究与保护提供新的思路。