Department of Biology, University of Missouri, St. Louis, MO 63121, USA.
Ecol Lett. 2013 Sep;16(9):1186-94. doi: 10.1111/ele.12156. Epub 2013 Jul 15.
The hypothesis of phylogenetic niche conservatism proposes that most extant members of a clade remain in ancestral environments because expansion into new ecological space imposes a selectional load on a population. A prediction that follows is that local assemblages contain increasingly phylogenetically clustered subsets of species with increasing difference from the ancestral environment of a clade. We test this in Australian Meliphagidae, a continental radiation of birds that originated in wet, subtropical environments, but subsequently spread to drier environments as Australia became more arid during the late Cenozoic. We find local assemblages are increasingly phylogenetically clustered along a gradient of decreasing precipitation. The pattern is less clear along a temperature gradient. We develop a novel phyloclimatespace to visualise the expansion of some lineages into drier habitats. Although few species extend into arid regions, those that do occupy larger ranges and thus local species richness does not decline predictably with precipitation.
系统发育生态位保守假说提出，一个进化枝的大多数现存成员仍保留在祖先环境中，因为向新的生态空间扩张会对种群施加选择压力。随之而来的一个预测是，随着与进化枝祖先环境的差异增大，局部集合包含越来越系统发育聚类的物种子集。我们在澳大利亚吸蜜鸟科（Meliphagidae）中验证了这一假说，这是一种起源于潮湿亚热带环境的鸟类大陆辐射，但随着澳大利亚在新生代晚期变得更加干旱，它们随后扩散到干燥的环境中。我们发现，随着降水的减少，局部集合在沿梯度逐渐表现出系统发育聚类。而沿着温度梯度的模式则不那么明显。我们开发了一种新颖的系统发育气候空间，以可视化一些谱系向干燥生境的扩展。尽管很少有物种延伸到干旱地区，但那些确实占据更大范围的物种，因此局部物种丰富度不会随着降水的减少而可预测地下降。
