Hammond Ashley S, Almécija Sergio
Center for Advanced Study of Human Paleobiology, Department of Anthropology, George Washington University, Washington, District of Columbia, 20052.
Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Barcelona, Spain.
Anat Rec (Hoboken). 2017 May;300(5):828-844. doi: 10.1002/ar.23545.
Elucidating the pelvic morphology of the Pan-Homo last common ancestor (LCA) is crucial for understanding ape and human evolution. The pelvis of Ardipithecus ramidus has been the basis of controversial interpretations of the LCA pelvis. In particular, it was proposed that the lower ilium became elongate independently in the orangutan and chimpanzee clades, making these taxa poor analogues for the pelvis of the LCA. This study examines the variation in relative lower ilium height between and within living and fossil hominoid species (and other anthropoids), and models its evolution using available fossil hominoids as calibration points. We find nuanced differences in relative lower ilium height among living hominoids, particularly in regards to gorillas, which do not have elongate lower ilia (because they are likely to represent the plesiomorphic hominoid condition for this trait). We also show that differences in relative lower ilium height among hominoid taxa are not readily explained by differences in size between species. Our maximum likelihood ancestral state reconstructions support inferences that chimpanzees (Pan troglodytes in particular) and orangutans evolved their elongate lower ilia independently. We also find that the predicted lower ilium height of the Pan-Homo LCA is shorter than all great apes except gorillas. This study adds to a growing body of evidence that finds different regions of the body show different evolutionary histories in different hominoids, and underscores that the unique combinations of morphologies of each modern and fossil hominoid species should be considered when reconstructing the mosaic nature of the Pan-Homo LCA. Anat Rec, 300:828-844, 2017. © 2017 Wiley Periodicals, Inc.
阐明泛人科最后一个共同祖先（LCA）的骨盆形态对于理解猿类和人类的进化至关重要。拉密达地猿的骨盆一直是对LCA骨盆有争议解释的基础。特别是，有人提出，在猩猩和黑猩猩分支中，髂骨下部独立变长，使得这些类群不太适合作为LCA骨盆的类似物。本研究考察了现存和化石类人猿物种（以及其他灵长类动物）之间以及内部相对髂骨下部高度的差异，并以现有的化石类人猿作为校准点对其进化进行建模。我们发现现存类人猿在相对髂骨下部高度上存在细微差异，特别是大猩猩，它们的髂骨下部没有变长（因为它们可能代表了该性状的原始类人猿状态）。我们还表明，类人猿分类群之间相对髂骨下部高度的差异不能简单地用物种间大小差异来解释。我们的最大似然祖先状态重建支持了这样的推断，即黑猩猩（特别是普通黑猩猩）和猩猩独立进化出了变长的髂骨下部。我们还发现，泛人科LCA预测的髂骨下部高度比除大猩猩之外的所有大猩猩都短。这项研究增加了越来越多的证据，这些证据表明身体的不同区域在不同类人猿中显示出不同的进化历史，并强调在重建泛人科LCA的镶嵌性质时，应考虑每个现代和化石类人猿物种独特的形态组合。《解剖学记录》，300:828 - 844，2017年。© 2017威利期刊公司。
