Doctoral Dissertation Research: Functional Morphology and Macroevolution of the Mammalian Cervical Vertebral Column

两足运动是人类进化谱系的一个标志性特征，代表了从猿和其他灵长类动物的主要转变。这种关键的转变可以通过对颈部的研究来研究，因为人类的颈部在两足运动时适应于平衡和稳定头部。这个博士研究项目将在不同的哺乳动物样本中测试颈部骨骼的形状与运动和姿势的关系。这一发现将用于解释来自已灭绝人类亲属的颈骨化石，以了解他们早期的两足动物形式，并可能为临床研究提供信息。该项目还将支持通过数字存储库共享三维扫描数据，并培训和指导学生研究人员，包括那些在科学领域代表性不足的群体。古人类化石记录中的颈椎可以让我们深入了解头、颈和躯干在关键运动和姿势转换过程中的相互作用。然而，目前对这些化石的功能解释仅限于“类似人类”的颈部活动或“类似猿”的颈部姿势等大类。本论文的目的是通过实验测试颈椎形状与颈部功能、运动模式和躯干姿势的关系，来改善古人类颈部重建。这一目标将通过三个目标来实现：1)使用弯曲力学实验量化椎体形状和颈部活动之间的关系，2)使用虚拟重建方法开发活体物种的颈部姿势模型，以及3)使用系统发育比较方法评估不同哺乳动物群体椎体形状变化的模式。这些目标将在灵长类动物、啮齿动物和有袋动物的广泛样本中进行测试。这些类群包含具有独立进化形式的两足运动和直立躯干姿势的物种，允许独立验证形式-功能关系。该项目将为定量解释颈椎化石的功能信息提供必要的基础数据，进一步加深我们对早期人类两足行走的本质和生物力学需求的理解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Bipedal locomotion is a hallmark trait of the human evolutionary lineage, representing a major transition away from the apes and other primates. This pivotal shift can be investigated through studies of the neck, as the human neck is adapted to balance and stabilize the head during bipedal movements. This doctoral research project will test how the shape of the bones of the neck relate to locomotion and posture in a diverse sample of mammals. The findings will be used to interpret fossilized neck bones from extinct human relatives to learn about their early forms of bipedalism, as well as potentially informing clinical research. This project will also support the sharing of three-dimensional scan data through digital repositories and the training and mentorship of student researchers, including those from groups underrepresented in scientific fields. Cervical vertebrae in the hominin fossil record can provide insight into the interplay between the head, neck and trunk during key locomotor and postural transitions. Currently, however, functional interpretations of these fossils are limited to broad categories such as "human-like" neck mobility or "ape-like" neck posture. The goal of this dissertation is to improve hominin neck reconstructions by experimentally testing how cervical vertebral shape relates to neck function, locomotor mode, and trunk posture. This goal will be addressed in three objectives: 1) quantify the relationship between vertebral shape and neck mobility using bending mechanics experiments, 2) develop neck posture models in living species using virtual reconstruction methods, and 3) evaluate patterns of vertebral shape change across diverse mammalian groups using phylogenetic comparative methods. The objectives will be tested in a broad sample of primates, rodents, and marsupials. These groups contain species with independently-evolved forms of bipedal locomotion and upright trunk posture, allowing for independent verification of form-function relationships. This project will provide the foundational data necessary to quantitatively interpret functional information from cervical vertebral fossils, furthering our understanding of the nature and biomechanical demands of bipedalism in early hominins.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.