The Southwest Mountainous region of the eastern Himalayas is a hotspot with extraordinarily high biodiversity and endemism, but the processes that have driven this unique diversity are largely unknown. We evaluated pr...The Southwest Mountainous region of the eastern Himalayas is a hotspot with extraordinarily high biodiversity and endemism, but the processes that have driven this unique diversity are largely unknown. We evaluated processes that have con- tributed to the current observed high genetic diversity in this region by integrating comparative phylogeography with ecological niche modeling in a study of two representative birds of the Southwest Mountains： the black-throated bushtit Aegithalos concinnus and the Elliot＇s laughing thrush Garrulax elliotii. Mitochondrial DNA analyses revealed multiple divergent genetic lineages, which are roughly congruent with the north, south and east eco-subregion division of the Southwest Mountains. This strong geo- graphical structure in these two species suggests that lineage diversification has proceeded in situ between the eco-subregions of the Southwest Mountains. During Pleistocene glaciations, the two species responded differently to climatic fluctuations. A. con- cinnus maintained rather stable habitats, mostly evergreen forests, during glacial cycles and thus kept a stable population size and further accumulated genetic diversity. In contrast, G. elliotii, which is mostly active in shrublands, has shifted its suitable habitats with glacial cycles. This species dispersed to low elevation areas during glacial periods, which provided multiple opportunities for gene admixture. The admixture causes the mixing of previously isolated genetic lineages and thus obscures the pattern of genetic variation [Current Zoology 61 （5）： 935-942, 2015].展开更多
基金We sincerely thank Chuanying Dai for providing mtDNA sequences of the Aegithalos coneinnus. We also thanks Town Peterson for providing the analysis protocol for the ecological niche model, and Robert G. Moyle for the protocol of genetic analyses. This research was supported by grants from the National Science Foundation of China （Nos 31471990, 31172064 to Y.Q. and 31330073, 30925008 to F.L.） and the Ministry of Science and Technology of the People＇s Republic of China （MOST Grant No. 2011FY120200-3）.
文摘The Southwest Mountainous region of the eastern Himalayas is a hotspot with extraordinarily high biodiversity and endemism, but the processes that have driven this unique diversity are largely unknown. We evaluated processes that have con- tributed to the current observed high genetic diversity in this region by integrating comparative phylogeography with ecological niche modeling in a study of two representative birds of the Southwest Mountains： the black-throated bushtit Aegithalos concinnus and the Elliot＇s laughing thrush Garrulax elliotii. Mitochondrial DNA analyses revealed multiple divergent genetic lineages, which are roughly congruent with the north, south and east eco-subregion division of the Southwest Mountains. This strong geo- graphical structure in these two species suggests that lineage diversification has proceeded in situ between the eco-subregions of the Southwest Mountains. During Pleistocene glaciations, the two species responded differently to climatic fluctuations. A. con- cinnus maintained rather stable habitats, mostly evergreen forests, during glacial cycles and thus kept a stable population size and further accumulated genetic diversity. In contrast, G. elliotii, which is mostly active in shrublands, has shifted its suitable habitats with glacial cycles. This species dispersed to low elevation areas during glacial periods, which provided multiple opportunities for gene admixture. The admixture causes the mixing of previously isolated genetic lineages and thus obscures the pattern of genetic variation [Current Zoology 61 （5）： 935-942, 2015].
