Postcranial Dimorphism in Primates

了解男性和女性在身体大小上的差异(二相性)对于确定现存和灭绝物种骨骼变化的生物学意义至关重要。此外，二形性为重建灭绝物种的行为提供了一些唯一的证据。后颅症提供了有关已灭绝物种的体型和体型二型性的关键信息。然而，考虑到大多数后颅骨的不规则形状和化石记录的碎片化性质，可以收集和分析的数据类型有限。这项研究将使用新的激光扫描技术来捕捉三维点云中的颅后骨形态，并开发使用POLYWORKS分析软件评估表面形态的技术。将收集27个灵长类动物的比较样本的数据，重点是测量真实的关节表面面积、骨横截面形状和体积。将开发进一步的几何测量，重点是确定男性和女性在骨曲率、关节表面方向和地形以及肌肉附着区大小方面的差异。分析将量化物种内和物种之间的性别差异模式，评估骨骼和身体尺寸二型性之间的关系，并开发从骨骼遗骸中重建尺寸二型性的方法。该项目的结果将显著提高我们对传统技术无法获得的骨骼形态的特征和评估方面的能力。比较数据库将使我们能够更好地了解灭绝物种的大小、二形性和颅后形态的演变。这项研究的更广泛影响包括有机会培训学生进行骨骼形式比较研究的尖端技术，以及开发方法学，为今后在生物和临床领域对灵长类动物和人类进行生物力学和比较研究提供巨大潜力。最后，扫描的数据将提供给其他研究人员，提供进一步分析的机会，并通过以非侵入性的方式永久记录数据，潜在地减少不可替代的博物馆收藏品的磨损。

Understanding male and female differences (dimorphism) in body size is critical for determining the biological meaning of skeletal variation in living and extinct species. Furthermore, dimorphism provides some of the only evidence for reconstructing behavior in extinct species. Postcrania offer critical information about body size and size dimorphism in extinct species. However, given the irregular form of most postcranial bones and fragmentary nature of the fossil record, the types of data that can be gathered and analyzed have been limited. This study will employ new laser-scanning technology to capture postcranial bone form in 3-D point clouds, and develop techniques for assessing surface form using POLYWORKS analytical software. Data will be gathered for a comparative sample of 27 primates, with a focus on measuring true joint surface areas, bone-cross sectional form, and volumes. Further geometric measurements will be developed, with an emphasis on identifying male and female differences in bone curvature, joint surface orientations and topography, and the size of muscle attachment areas. Analyses will quantify patterns of sex differences within and across species, evaluate the relationship between skeletal and body size dimorphism, and develop methods for reconstructing size dimorphism from skeletal remains. Results from this project will significantly improve our ability to characterize and evaluate aspects of bone form that have been inaccessible using traditional techniques. The comparative data base will allow a more refined understanding of the evolution of size dimorphism and postcranial morphology in extinct species. The broader impacts of this research include opportunities to train students in cutting edge technology for comparative studies of skeletal form, and the development of methodologies which offer enormous potential for future biomechanical and comparative studies in primates and humans in biological and clinical fields. Finally, scanned data will be made available to other researchers, offering opportunities for further analysis and potentially reducing wear and tear on irreplaceable museum collections by permanently recording data in a non-invasive manner.