Rowe Kevin C, Heske Edward J, Brown Patrick W, Paige Ken N
Department of Animal Biology, University of Illinois, Urbana, IL 61801, USA.
Proc Natl Acad Sci U S A. 2004 Jul 13;101(28):10355-9. doi: 10.1073/pnas.0401338101. Epub 2004 Jul 12.
The contemporary distribution of biological diversity cannot be understood without knowledge of how organisms responded to the geological and climatic history of Earth. In particular, Quaternary expansions and contractions of glacial ice sheets are thought to have played an important role in shaping the distribution of biodiversity among current populations in the north-temperate region. In the central U.S., fossil and palynological data provide support for the maintenance of a large southeastern refuge during the last glacial maximum, and many temperate organisms are believed to have responded to glacial expansion by shifting their ranges to southern refugia and recolonizing northward to track the receding ice sheets. Thus, organisms are assumed to track favorable climates, and species ranges are expected to have shifted significantly. Here we present data from a deciduous forest vertebrate, the eastern chipmunk (Tamias striatus) in the central U.S., indicating the maintenance of multiple refugial sources as well as a southward expansion from a northern refugium. These results challenge the view that, during glacial maxima, organisms must have migrated south out of their ranges to track favorable climates.
如果不了解生物如何应对地球的地质和气候历史，就无法理解当代生物多样性的分布情况。特别是，第四纪冰盖的扩张和收缩被认为在塑造北温带地区当前种群间生物多样性的分布方面发挥了重要作用。在美国中部，化石和孢粉学数据支持了在末次盛冰期期间东南部存在一个大型避难所的观点，并且许多温带生物被认为通过将其分布范围转移到南部避难所并向北重新定殖以追踪后退的冰盖来应对冰川扩张。因此，假定生物会追踪适宜的气候，并且物种分布范围预计已发生显著变化。在这里，我们展示了来自美国中部落叶林脊椎动物东部花栗鼠（Tamias striatus）的数据，表明存在多个避难所来源以及从北部避难所向南的扩张。这些结果挑战了这样一种观点，即在盛冰期期间，生物必定已从其分布范围向南迁移以追踪适宜的气候。
