Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Mol Ecol. 2010 Jan;19(2):338-51. doi: 10.1111/j.1365-294X.2009.04445.x. Epub 2009 Dec 3.
Pleistocene climate fluctuations have shaped the patterns of genetic diversity observed in extant species. In contrast to Europe and North America where the effects of recent glacial cycles on genetic diversity have been well studied, the genetic legacy of the Pleistocene for the Qinghai-Tibetan (Tibetan) plateau, a region where glaciation was not synchronous with the North Hemisphere ice sheet maxima, remains poorly understood. Here, we compared the phylogeographical patterns of five avian species on the Qinghai-Tibetan plateau by three mitochondrial DNA fragments: the Tibetan snow finch (Montifringilla adamsi), the Blanford's snow finch (Pyrgilauda blanfordi), the horned lark (Eremophila alpestris), the twite (Carduelis flavirostris) and the black redstart (Phoenicurus ochruros). Our results revealed the three species mostly distributed on the platform region of the plateau that experienced population expansion following the retreat of the extensive glaciation period (0.5-0.175 Ma). These results are at odds with the results from avian species of Europe and North America, where population expansions occurred after Last Glacial Maximum (LGM, 0.023-0.018 Ma). A single refugium was identified in a restricted semi-continuous area around the eastern margin of the plateau, instead of multiple independent refugia for European and North American species. For the other two species distributed on the edges of the plateau (the twite and black redstart), populations were maintained at stable levels. Edge areas are located on the eastern margin, which might have had little or no ice cover during the glaciation period. Thus, milder climate may have mitigated demographic stresses for edge species relative to the extremes experienced by platform counterparts, the present-day ranges of which were heavily ice covered during the glaciation period. Finally, various behavioural and ecological characteristics, including dispersal capacities, habitat preference and altitude specificity along with evolutionary history might have helped to shape different phylogeographical structures appearing in these five species.
更新世气候波动塑造了现存物种中观察到的遗传多样性模式。与欧洲和北美的情况形成鲜明对比的是，这些地区的遗传多样性受到最近冰川周期的影响已有深入研究，而青藏高原的遗传遗产——一个冰川作用与北半球冰盖最大值不同步的地区——仍知之甚少。在这里，我们通过三个线粒体 DNA 片段比较了青藏高原上五种鸟类的系统地理模式：藏雪雀（Montifringilla adamsi）、棕眉山岩鹨（Pyrgilauda blanfordi）、角百灵（Eremophila alpestris）、红腹朱雀（Carduelis flavirostris）和红喉山鹧鸪（Phoenicurus ochruros）。我们的研究结果表明，三种主要分布在高原平台地区的物种经历了种群扩张，而这一扩张发生在广泛的冰川期（0.5-0.175 万年前）消退之后。这些结果与欧洲和北美的鸟类物种的结果不一致，在那里种群扩张发生在末次冰盛期（LGM，0.023-0.018 万年前）之后。在高原东缘的一个有限的半连续区域确定了一个单一的避难所，而不是像欧洲和北美的物种那样有多个独立的避难所。对于另外两种分布在高原边缘的物种（红腹朱雀和红喉山鹧鸪），种群保持在稳定水平。边缘地区位于高原的东缘，在冰川期可能几乎没有或没有冰盖。因此，与高原平台物种所经历的极端情况相比，气候的温和可能减轻了边缘物种的人口压力，这些物种的现代分布范围在冰川期曾被大面积的冰覆盖。最后，各种行为和生态特征，包括扩散能力、栖息地偏好和海拔特异性，以及进化历史，可能有助于塑造这五个物种中出现的不同系统地理结构。
