干旱荒漠区是我国特殊的自然地理单元，也是世界干旱区生物多样性的关键区域。揭示其形成与演化对旱适应物种的遗传分化和群体动态的影响具有重要意义。冷适应物种分布区在冰盛期扩张而在间冰期收缩的模型通常被接受。鉴于干旱荒漠区在冰盛期沙漠面积扩张，推测耐干旱物种的分布区符合冰盛期扩张模型。本项目拟选择该区域广泛分布的三种典型的耐干旱蜥蜴（叶城沙蜥、虫纹麻蜥和西域沙虎）为对象，利用野外调查取样，联合遗传（线粒体、核DNA序列和微卫星标记）和环境数据，运用整合的谱系地理学和生态位模型的理论和方法来重建基因谱系的时空格局、追溯种群的进化历史。既检验冰盛期扩张模型，又解析生境隔离（山脉、绿洲）和地理距离对遗传分歧的贡献，还评估三者谱系地理格局的一致性和特殊性。研究结果将为更全面认识第四纪冷暖交替和亚洲中部干旱区的干旱化过程对生物分布的影响提供新的信息，也将为探讨群落水平共享的生物地理学过程提供新的线索。

The arid desert region is a particular geographical unit in China, and it is also a key area of biodiversity of the arid areas in the world. It is very important to unravel the effects of its formation and evolution on genetic divergence and historical population dynamics of arid-adpated species endemic to this region. A model of range expansions during glacial maxima (GM) for cold-adapted species is generally accepted for the Northern Hemisphere. Given that GM in the arid desert region resulted in the expansion of desert rather than glaciations, it could be expected that arid-adapted species might have had expanded ranges at GM and contracted ranges at interglaciation, as cold-adapted species did in the Northern Hemisphere. On the basis of previous studies, three co-distributed and typical arid-tolerant lizards, i.e., Phrynocephalus axillaris, Eremias vermiculata and Teratoscincus przewalskii, are chosen to study the shared historical demographies across the arid desert region, and to explore the ways in which historical geological and climatic events have influenced local adaptation and diversification of populations. We will trace the evolutionary history of populations by combining genetic (mitochondrial and multiple nuclear DNA loci and microsatellite markers) with environmental data, and using integrative phylogeographical analyses such as ecological niche modeling and approximate Bayesian computation. Our objectives are (i) to test alternative GM expansion model; (ii) to explore the relative contribution of environmental isolation (caused by mountains and oases) versus geographical distance to the observed genetic divergences occurring among populations within a species; and (iii) to assess the concordant or nonconcordant phylogeographical patterns by testing hypotheses of shared evolutionary history among the co-distributed lizard groups. The results of this study will add new information to a more comprehensive understanding of how climatic oscillations in the Quaternary and the aridification of Arid Central Asia affected shifts in species’ distribution, and can also provide new clues to explore the evidence of shared biogeographical processes at the community level.