Doctoral Dissertation Improvement Grant: Locomotor Function and Phylogeny: Implications for Interpreting Extinct Hominoid Morphology

进化关系(即系统发育)和功能在骨骼解剖学表现中的相互作用使众所周知的类人猿(类人猿和人类谱系成员)的运动模式的重建复杂化，如南方古猿和赫塞罗尼领事。这些物种在前肢上表现出独特的特征组合，代表了运动行为的相反证据。为了了解哪些前肢特征对预测灭绝的类人猿物种的运动行为最有用，本研究探索了前肢特征的变异与观察到的现存灵长类动物运动行为之间的相对对应关系。这个项目的主要目标是确定与运动行为相关的前肢特征中功能信号的相对强度，并证明这些特征的表现受到系统发育的制约程度。将收集代表各种现存灵长类物种的骨骼样本的三维几何形态数据。地标数据将收集在前肢元素上，并将提取线性测量作为形状变量。这些形状变量将与广义最小二乘分析中公布的运动行为百分比进行回归，以说明系统发育。形状变量将根据它们与运动行为的对应关系进行排序。预测模型将被构建并用于对已灭绝的南方古猿和埃塞洛尼领事进行的更精细的运动行为评估。这一新方法将加强对现存灵长类动物运动和骨骼解剖之间关系的理解，使研究人员能够更准确地重建化石物种的行为。此外，这项研究通过证明需要更多地强调系统发育和功能之间的复杂相互作用，对古生物学和研究人员如何在功能研究中看待骨骼特征具有更广泛的影响。

The interplay of evolutionary relationships (i.e., phylogeny) and function in the manifestation of skeletal anatomy complicates reconstructions of locomotor patterns in well-known fossil hominoids (apes and members of the human lineage) such as Australopithecus afarensis and Proconsul heseloni. These species demonstrate unique combinations of features in the forelimb that represent contrasting evidence for locomotor behavior. In order to understand which forelimb traits are most useful in predicting the locomotion of extinct hominoid species, this research explores the relative correspondence between variation in forelimb characters and observed locomotor behaviors of extant primates. The main objective of this project is to determine the relative strength of the functional signal in forelimb features related to locomotor behavior and to demonstrate the degree to which the manifestation of these traits is constrained by phylogeny. Three-dimensional geometric morphometric data will be collected on skeletal samples representing a wide range of extant primate species. Landmark data will be collected on forelimb elements, and linear measurements will be extracted to be employed as shape variables. These shape variables will be regressed against published percentages of locomotor behavior in a generalized least-squares analysis to account for phylogeny. Shape variables will be ranked based on their correspondence to locomotor behavior. Predictive models will be constructed and used in more refined assessments of the locomotor behavior performed by the extinct hominoids Australopithecus afarensis and Proconsul heseloni. This novel approach will enhance understanding of the relationship between locomotion and skeletal anatomy in living primates, allowing researchers to more accurately reconstruct the behavior of fossil species. In addition, this research has broader implications for paleontology and how researchers view skeletal features in functional studies by demonstrating the need for a greater emphasis on the complex interplay between phylogeny and function.