Department of Anatomy, Howard University College of Medicine, 520 W St. N.W., Washington, D.C., 20059, USA; Center for the Advanced Study of Human Paleobiology, Department of Anthropology, The George Washington University, Washington, D.C., 20052, USA.
Center for the Advanced Study of Human Paleobiology, Department of Anthropology, The George Washington University, Washington, D.C., 20052, USA.
J Hum Evol. 2024 May;190:103494. doi: 10.1016/j.jhevol.2024.103494. Epub 2024 Apr 1.
The body proportions of extant animals help inform inferences about the behaviors of their extinct relatives, but relationships between body proportions, behavior, and phylogeny in extant primates remain unclear. Advances in behavioral data, molecular phylogenies, and multivariate analytical tools make it an opportune time to perform comprehensive comparative analyses of primate traditional limb length proportions (e.g., intermembral, humerofemoral, brachial, and crural indices), body size-adjusted long bone proportions, and principal components. In this study we used a mix of newly-collected and published data to investigate whether and how the limb length proportions of a diverse sample of primates, including monkeys, apes, and modern humans, are influenced by behavior and phylogeny. We reconfirm that the intermembral index, followed by the first principal component of traditional limb length proportions, is the single most effective variable distinguishing hominoids and other anthropoids. Combined limb length proportions and positional behaviors are strongly correlated in extant anthropoid groups, but phylogeny is a better predictor of limb length proportion variation than of behavior. We confirm convergences between members of the Atelidae and extant apes (especially Pan), members of the Hylobatidae and Pongo, and a potential divergence of Presbytis limb proportions from some other cercopithecoids, which correlate with adaptations for forelimb-dominated behaviors in some colobines. Collectively, these results substantiate hypotheses indicating that extinct hominins and other hominoid taxa can be distinguished by analyzing combinations of their limb length proportions at different taxonomic levels. From these results, we hypothesize that fossil skeletons characterized by notably disparate limb length proportions are unlikely to have exhibited similar behavioral patterns.
现存动物的身体比例有助于推断其已灭绝亲属的行为，但现存灵长类动物的身体比例、行为和系统发育之间的关系仍不清楚。行为数据、分子系统发育和多元分析工具的进步使得现在是对灵长类动物传统肢体长度比例（例如，肢体间、肱骨股骨、臂和小腿指数）、身体大小调整后的长骨比例和主成分进行全面比较分析的好时机。在这项研究中，我们使用了新收集和已发表的数据的组合，来研究不同灵长类动物（包括猴子、猿和现代人类）的肢体长度比例是否以及如何受到行为和系统发育的影响。我们再次证实，肢体间指数，其次是传统肢体长度比例的第一主成分，是区分原猴类和其他类人猿的最有效变量。在现存的类人猿群体中，组合肢体长度比例和位置行为强烈相关，但系统发育是肢体长度比例变化的更好预测因子，而不是行为。我们确认了在 Atelidae 和现存猿类（尤其是 Pan）、Hylobatidae 和 Pongo 之间的趋同，以及 Presbytis 肢体比例与某些 colobines 中的前肢主导行为的适应之间的潜在分歧。总的来说，这些结果证实了一些假说，即通过分析不同分类水平的肢体长度比例的组合，可以区分已灭绝的人类和其他类人猿分类群。根据这些结果，我们假设具有明显不同肢体长度比例的化石骨骼不太可能表现出相似的行为模式。
