生物多样性 ›› 2014, Vol. 22 ›› Issue (1): 40-50.DOI: 10.3724/SP.J.1003.2014.13144

所属专题: 基因组和生物多样性

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基因组时代的新视野: 东南亚哺乳动物类群在第四纪冰河时期多样性的起源与分化

苗林, 罗述金*()   

  1. 北京大学生命科学学院, 北京大学-清华大学生命科学联合中心, 北京 100871
  • 收稿日期:2013-06-24 接受日期:2013-12-25 出版日期:2014-01-20 发布日期:2014-02-10
  • 通讯作者: 罗述金
  • 基金资助:
    国家自然科学基金面上项目(31271320)

Diversification of Southeast Asian mammals during the Quaternary glaciation: insights from the genomic era

Lin Miao, Shu-Jin Luo*()   

  1. College of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871
  • Received:2013-06-24 Accepted:2013-12-25 Online:2014-01-20 Published:2014-02-10
  • Contact: Luo Shu-Jin

摘要:

东南亚地区东起菲律宾群岛, 西至印度次大陆, 北及中国中部, 南至巽他群岛, 涵盖了世界上25个最重要的生物多样性热点地区之中的6个, 具有极其重要的全球生物多样性保护的战略意义。该地区复杂的地质地貌和气候历史使其动植物的种类和数量都极为丰富。经典的生物地理分界线华莱士线和克拉地峡将该地区进一步划分出包括部分巽他群岛和马来半岛在内的南部巽他区和北部印度支那区两个生物多样性热点地区。主要基于形态学的生物地理学研究认为巽他区和印度支那区通过马来半岛陆地相连, 并且第四纪大部分时间海平面下降形成大陆桥, 直到一万年前该地区的众多岛屿仍与大陆连接, 促进了哺乳动物的种群迁徙与基因交流, 因此物种种群间的差别将很细微。然而近来分子遗传学研究表明, 由于其他生态因素制约, 哺乳动物的迁移能力可能比以往认为的低, 大陆桥的存在并不一定导致迁徙的发生, 许多种群的隔离早在200万年前便已形成, 并且没有因为后来冰川期海平面降低而恢复种群交流, 而距今7.3万年前发生的苏门答腊多巴超级火山爆发也可能进一步影响了物种间和物种内多样性的形成和分化。通过已有的东南亚哺乳动物种群遗传学研究结果, 我们认为物种间或种群间的差异主要表现为三个层次: 巽他区种群与印度支那区种群间约百万年尺度的分化, 巽他区不同岛屿种群间约数十万年尺度的分化, 以及发生于晚更新世的分化事件。已有的东南亚种群遗传学研究主要采用线粒体及核基因多位点数据进行分析, 而种群基因组学分析则使得获得详尽的种群历史动态成为可能, 并使我们可以进一步了解东南亚哺乳动物类群所经历的物种形成过程。

关键词: 东南亚, 生物地理学, 哺乳动物, 种群基因组学, 第四纪

Abstract:

Southeast (SE) Asia refers to the region east to the Philippine islands, west to the Indian subcontinent, north to central China and south to the Sunda islands. This region includes six of the world’s 25 biodiversity hotspots and is of strategic significance in global biodiversity conservation. The complicated geological and climatological history of this region has resulted in extremely high species diversity and endemism. Two classic biogeographic boundaries, the Wallace Line and the Isthmus of Kra, divide SE Asia into the Indochinese province to the north and Sundaic province to the south. Because the Indochinese and Sundaic provinces are connected today through the Malay Peninsula and the Sunda shelf was exposed for the majority of time during the Quaternary glaciation, previous biogeographic studies have proposed that gene flow occurred between mainland and different island populations causing low divergence in the region. However, recent molecular genetic studies have reported that migration of terrestrial mammal populations was not as great as previously thought due to ecological restrictions. Thus, deep vicariant divergence was present in several mammals as early as two million years ago and appeared not to have been affected by gene flow following the formation of land bridges during later glacial periods. Furthermore, the super eruption of the Toba volcano in Sumatra about 73,000 years ago may have intensified divergence. A literature review has indicated three hierarchical levels present in the formation of mammalian diversity in SE Asia. These include populations between the Indochinese and Sundaic provinces which diverged millions of years ago, populations among the Sunda Islands which diverged hundreds of thousands of years ago, and Late Pleistocene biogeographic events causing demographic changes. Most of the previous population genetic studies on SE Asia mammals were based on analyses of mitochondrial or nuclear DNA data. Recent advances in population genomics provide new opportunities to obtain a comprehensive understanding of the demographic history and speciation processes of SE Asian mammals during the Quaternary glaciation.

Key words: Southeast Asia, biogeography, mammal, population genomics, Quaternary