Doctoral Dissertation Improvement: Biomechanical and Behavioral Significance of the Neanderthal Femur

许多研究人员认为，与现代人相比，尼安德特人的股骨具有更大的粗壮和综合力量，这是由于在觅食和狩猎时延长了使用时间。这就是所谓的流动性假说。这项研究通过检测活着的灵长类动物的骨骼特征和测距行为来检验这一假设，以确定使用是否等同于更强大的生命力。研究结果将为人类学、灵长类动物学、整形外科、工程学和数量遗传学领域提供信息。这项研究还影响了对股骨力学环境的理解，这可能有助于髋关节假体的发展。此外，这项研究提高了对遗传学和股骨形态之间的相关性的理解，并促进了工程学和社会科学之间的跨学科。尼安德特人的股骨在四个方面与现代人类的股骨不同，这表明它更强壮，或者说在生物力学上更强大：它更弯曲，有更厚的骨，圆形而不是椭圆形的干骨，以及更小的颈-干角。这些差异可以用流动性假说来解释。由于生存战略严重依赖于对动物资源的开发，尼安德特人可能比现代人走得更远，寻找食物，因此会在更大程度上负载他们的下肢。本研究采用三阶段方法对流动假说进行了检验。第一阶段建立了35种现存灵长类动物的活动性与股骨骨骼特征之间的比较基础，这些物种具有已记录的测距行为，使用的方法将产生和传播数百个计算机化的3D表面模型。第二阶段分析了关键骨骼特征可遗传或环境产生的程度，使用21个品系的近亲繁殖实验室小鼠，总计413个个体。最后一个阶段探索在每个物种的特定解剖背景下完整的尼安德特人和现代人股骨的强度，使用工程技术(有限元分析)，旨在研究复杂结构如何对载荷做出反应，并包括现实肌肉和髋关节反作用力的影响。

Many researchers have suggested that the greater robusticity and resultant strength of Neandertal femora, compared with those of modern humans, is due to extended use while foraging and hunting. This is known as the mobility hypothesis. This study examines that hypothesis by examining skeletal features and ranging behaviors in a large sample of living primates to determine if use equates with greater robusticity. Results will inform the fields of anthropology, primatology, orthopedics, engineering, and quantitative genetics. The study also impacts understanding of the femur's mechanical environment, which could aid the development of hip prosthetics. Furthermore, this study improves understanding of the correlation between genetics and femoral morphology, and promotes interdisciplinarity between engineering and social sciences.The Neanderthal femur differs from that of recent modern humans in four ways that suggest it is more robust, or biomechanically stronger: it is more curved, has thicker bone, a round rather than elliptical shaft, and a smaller neck-shaft angle. These differences may be explained by the mobility hypothesis. Due to subsistence strategies relying heavily on the exploitation of animal resources, Neanderthals may have been traveling farther than modern humans in search of food, and would thus be loading their lower limbs to a greater extent. This study tests the mobility hypothesis using a three phase approach. The first phase establishes a comparative basis relating mobility to femoral skeletal features in 35 species of living primates with documented ranging behavior, using a method that will produce and disseminate hundreds of computerized 3D surface models. The second phase analyzes the degree to which key skeletal features are heritable or environmentally produced using 21 strains of inbred laboratory mice totaling 413 individuals. The final phase explores the strength of complete Neanderthal and modern human femora within each species' particular anatomical context, using an engineering technique (finite element analysis) designed to investigate how complex structures respond to loads, and include the impact of realistic muscle and hip joint reaction forces.