Doctoral Dissertation Research: The evolution of human balance

在人类进化过程中，向直立姿势和两足运动的过渡与许多解剖学变化有关。本博士论文研究项目探讨了内耳解剖学中一个未被充分研究的方面，它有助于我们在运动时的平衡感。研究者比较了人类、灵长类动物和古人类化石的内耳解剖结构，并研究了它与头颈部姿势和颅骨解剖结构的关系。这个项目的结果促进了我们对古人类进化过程中与平衡相关的解剖结构如何随着向两足动物的过渡而变化的理解，并可能允许更好地从化石标本中重建姿势行为。该项目还有助于医学治疗，为人类前庭失调的潜力提供见解，并创建可量化和可重复的前庭解剖可视化，有助于精确的手术靶向和前庭假体的开发。在项目过程中，研究者将把3D打印模型、插图和结果的动画纳入纽约市的公共宣传计划，旨在向公众教授人类进化概念。这些项目包括美国自然历史博物馆的项目；雷曼学院的本科课程；以及在科学教育中使用多媒体和交互设计的本科生研讨会。前庭系统由位于内耳骨前庭内的半规管（检测角加速度）和耳石器官（检测线性加速度和相对于重力的头部倾斜）组成。与对灵长类动物半规管的大量研究相反，耳石器官的比较功能形态在很大程度上是未知的。这种知识差距限制了我们对灵长类动物进化的理解，更具体地说，是对人类头部和颈部姿势（头部定位和运动范围）的理解。本项目使用微计算机断层扫描和同步加速器共振相衬成像技术来创建耳石器官几何形状的包膜骨形态（骨前庭）的形态测量模型，以研究人类、灵长类动物和古人类化石的骨前庭的进化和功能形态。研究者研究了现代人类骨前庭的变异和功能，考虑了比较灵长类动物样本中骨前庭形态与头部位置和解剖结构之间的相关性，并比较了现代人类和重建的古人类化石的骨前庭特征。该研究阐明了前庭系统和头颈部姿势在整个人类进化过程中是如何相互变化的，并为未来研究骨前庭形态与现存灵长类动物和重建的古人类姿势行为的关系提供了基础。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。

During hominin evolution, the transition to upright posture and bipedal locomotion was associated with many anatomical changes. This doctoral dissertation research project examines an understudied aspect of inner ear anatomy that contributes to our sense of balance during movement. The investigator compares aspects of inner ear anatomy for humans, primates, and fossil hominins, and examines its relationship with head and neck posture and cranial anatomy. Results from this project advance our understanding of how anatomical structures associated with balance changed with the transition to bipedalism during hominin evolution and may allow for better reconstructions of postural behavior from fossil specimens. The project also contributes to medical treatment by providing insights into the potential for vestibular dysregulation in humans and creating a quantifiable and reproducible visualization of vestibular anatomy that aids precise surgical targeting and development of vestibular prostheses. During the course of the project the investigator will incorporate 3D printed models, illustrations, and animations of the results into public outreach programs in New York City designed to teach human evolutionary concepts to the public. These include programs at the American Museum of Natural History; undergraduate courses at Lehman College; and an undergraduate seminar on the use of multimedia and interactive design in science education.The vestibular system consists of the semicircular canals (detecting angular acceleration) and the otolith organs (detecting linear acceleration and head tilt relative to gravity) housed within the bony vestibule of the inner ear. In contrast to considerable study of the semicircular canals in primates, the comparative functional morphology of the otolith organs is largely unknown. This knowledge gap has limited our understanding of the evolution of primate, and more specifically human, head and neck posture (head positioning and range of motion). This project uses both Micro-Computed Tomography and Synchrotron Resonance Phase Contrast Imaging to create a morphometric model of the encasing bony morphology (bony vestibule) specific to otolith organ geometry in order to investigate the evolution and functional morphology of the bony vestibule in humans, primates, and fossil hominins. The investigator examines modern human bony vestibule variation and function, consider correlations between bony vestibule morphology and head position and anatomy in a comparative primate sample, and compare modern human and reconstructed fossil hominin bony vestibule features. The research clarifies how the vestibular system and head and neck posture changed alongside one another throughout human evolution and allow future study into the way(s) bony vestibule morphology is correlated with extant primate and reconstructed hominin postural behaviors.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.