School of Biological Science, Thomas Building, University of Auckland, Auckland, 1142, New Zealand.
Department of Ecology and Evolutionary Biology, School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, South Australia, 5005, Australia.
Evolution. 2019 Nov;73(11):2216-2229. doi: 10.1111/evo.13851. Epub 2019 Oct 14.
A defining character of adaptive radiations is the evolution of a diversity of morphological forms that are associated with the use of different habitats, following the invasion of vacant niches. Island adaptive radiations have been thoroughly investigated but continental scale radiations are more poorly understood. Here, we use 52 species of Australian agamid lizards and their Asian relatives as a model group, and employ three-dimensional geometric morphometrics to characterize cranial morphology and investigate whether variation in cranial shape reflects patterns expected from the ecological process of adaptive radiation. Phylogenetic affinity, evolutionary allometry, and ecological life habit all play major roles in the evolution of cranial shape in the sampled lizards. We find a significant association between cranial shapes and life habit. Our results are in line with the expectations of an adaptive radiation, and this is the first time detailed geometric morphometric analyses have been used to understand the selective forces that drove an adaptive radiation at a continental scale.
适应辐射的一个显著特征是，在占据空缺生态位后，生物会进化出多种多样的形态，这些形态与不同栖息地的利用有关。岛屿适应辐射已得到充分研究，但对大陆范围的辐射则了解较少。在这里，我们使用 52 种澳大利亚鬣蜥及其亚洲亲缘种作为模型组，采用三维几何形态测量学来描述颅骨形态，并研究颅骨形状的变化是否反映了适应辐射的生态过程所预期的模式。系统发育亲缘关系、进化的异速生长以及生态生活习性在取样蜥蜴的颅骨形状进化中都起着重要作用。我们发现颅骨形状与生活习性之间存在显著关联。我们的研究结果与适应辐射的预期一致，这也是首次使用详细的几何形态测量分析来了解在大陆范围内驱动适应辐射的选择压力。
