Upchurch Paul
Department of Earth Sciences, University College London, London, UK.
Trends Ecol Evol. 2008 Apr;23(4):229-36. doi: 10.1016/j.tree.2007.11.006. Epub 2008 Feb 13.
Fierce debate surrounds the history of organisms in the southern hemisphere; did Gondwanan break-up produce ocean barriers that imposed distribution patterns on phylogenies (vicariance)? Or have organisms modified their distributions through trans-oceanic dispersal? Recent advances in biogeographical theory suggest that the current focus on vicariance versus dispersal is too narrow because it ignores 'geodispersal' (i.e. expansion of species into areas when geographical barriers disappear), extinction and sampling errors. Geodispersal produces multiple, conflicting vicariance patterns, and extinction and sampling errors destroy vicariance patterns. This perspective suggests that it is more difficult to detect vicariance than trans-oceanic dispersal and that specialized methods must be applied if an unbiased understanding of southern hemisphere biogeography is to be achieved.
围绕南半球生物的历史存在激烈争论；冈瓦纳大陆的分裂是否产生了海洋屏障，从而在系统发育上形成了分布模式（隔离分化）？还是生物通过跨洋扩散改变了它们的分布？生物地理学理论的最新进展表明，目前对隔离分化与扩散的关注过于狭隘，因为它忽略了“地理扩散”（即当地理屏障消失时物种向其他地区的扩张）、灭绝和抽样误差。地理扩散会产生多种相互冲突的隔离分化模式，而灭绝和抽样误差会破坏隔离分化模式。这种观点表明，检测隔离分化比跨洋扩散更困难，并且如果要对南半球生物地理学有一个公正的理解，就必须应用专门的方法。
