Genetic consequences of climatic oscillations in the Quaternary
Genetic consequences of climatic oscillations in the Quaternary
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DOI：
10.1098/rstb.2003.1388
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发表时间：
2004-02-29
影响因子：
6.3
通讯作者：
Hewitt, GM
中科院分区：
文献类型：
--
作者：
Hewitt, GM
对过去几百万年气候波动的规模和频率的认识正在改变我们对进化如何进行的看法。这些重大事件导致了灭绝，并导致幸存的类群的范围不断发生变化。它们的空间影响取决于纬度和地形，在高纬度地区会发生广泛的灭绝和重新殖民，在热带地区会发生海拔变化和复杂的避难所。相关的种群动态随生活史和地理的不同而变化，并且种群和物种目前的遗传构成携带着这些过去动态的减弱信号。最近，DNA 系统发育地理学研究蓬勃发展，对北极、温带和热带地区的研究进行了回顾，寻找由此产生的遗传模式中原因的共性。北极物种表现出具有共同地理边界的独特的浅层遗传进化枝。因此，白令海峡在系统发育地理学上是独特的，但其作为避难源的作用是复杂的。北极类群并未表现出北温带物种南方丰富、北方纯净的共同遗传模式。欧洲和北美的温带避难区显示出许多类群相对较深的 DNA 差异，表明它们存在于几个冰河时期，并暗示了一种通过重复异域异域形成的物种形成模式。 DNA证据表明，欧洲温带物种在同一地区有不同的冰河后殖民模式，在之前的振荡中也有不同的殖民模式，而北美西北部地区是从北部、东部和南部殖民的。热带山地地区的谱系差异很大，通常分布在相对较小的地理区域，这表明它们从上新世就在那里生存。我们对避难所生物多样性的了解不足，将受益于进一步结合化石和遗传学研究。
An appreciation of the scale and frequency of climatic oscillations in the past few million years is modifying our views on how evolution proceeds. Such major events caused extinction and repeated changes in the ranges of those taxa that survived. Their spatial effects depend on latitude and topography, with extensive extinction and recolonization in higher latitudes and altitudinal shifts and complex refugia nearer the tropics. The associated population dynamics varied with life history and geography, and the present genetic constitution of the populations and species carry attenuated signals of these past dynamics. Phylogeographic studies with DNA have burgeoned recently and studies are reviewed from the arctic, temperate and tropical regions, seeking commonalities of cause in the resulting genetic patterns.Arctic species show distinct shallow genetic clades with common geographical boundaries. Thus Beringia is distinct phylogeographically, but its role as a refugial source is complex. Arctic taxa do not show the common genetic pattern of southern richness and northern purity in north-temperate species. Temperate refugial regions in Europe and North America show relatively deep DNA divergence for many taxa, indicating their presence over several Ice Ages, and suggesting a mode of speciation by repeated allopatry. DNA evidence indicates temperate species in Europe had different patterns of postglacial colonization across the same area and different ones in previous oscillations, whereas the northwest region of North America was colonized from the north, east and south. Tropical montane regions contain deeply diverged lineages, often in a relatively small geographical area, suggesting their survival there from the Pliocene. Our poor understanding of refugial biodiversity would benefit from further combined fossil and genetic studies.