Genetic diversification in the East Himalayas as revealed by comparative phylogeography of the black-throated bushtit and Elliot’s laughing thrush

• 来源期刊: 动物学报（英文版）
• 年，卷（期）: 2015,（5）
• 页码范围: 935-942
• 页数: 8页
• 语种: 英文

摘要

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 bushtitAegithalos concin-nus and the Elliot’s laughing thrushGarrulax 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 proceededin 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 ge-netic variation [Current Zoology 61 (5): 935–942, 2015].