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转变与许多解剖学上的变化有关。这篇博士论文的研究项目考察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中保持平衡感。研究人员比较了人类、灵长类动物和古人类化石的内耳解剖学，并研究了内耳解剖学与头颈部姿势和颅骨解剖的关系。该项目的结果促进了我们对与平衡相关的解剖结构如何随着原始人进化到两足动物的转变而变化的理解，并可能允许从化石标本中更好地重建姿势行为。该项目还通过提供对人类前庭调节失调的可能性的洞察，并创建可量化和可重现的前庭解剖可视化，帮助精确的外科定位和前庭假体的开发，从而为医疗做出贡献。在项目过程中，研究人员将把3D打印的模型、插图和结果的动画纳入纽约市的公共推广项目，旨在向公众传授人类进化概念。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；以及关于在科学教育中使用多媒体和交互设计的本科研讨会。前庭系统由位于内耳骨性前庭的半规管(检测角加速度)和耳石器官(检测线加速度和头部相对于重力的倾斜)组成。与灵长类动物半规管的大量研究相比，耳石器官的相对功能形态在很大程度上是未知的。这一知识差距限制了我们对灵长类进化的了解，更具体地说，限制了我们对人类、头部和颈部姿势(头部位置和运动范围)的了解。为了研究人类、灵长类动物和人类化石中骨前庭的进化和功能形态，本项目使用微型计算机断层摄影术和同步加速器共振相位对比度成像技术来创建耳石器官几何结构特有的包围骨形态(骨前庭)的形态计量模型。研究人员考察了现代人骨前庭的变异和功能，在一个比较的灵长类动物样本中考虑了骨前庭形态与头部位置和解剖学的相关性，并比较了现代人和重建的古人类骨前庭的特征。这项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(S)骨骼前庭形态与现存的灵长类动物和重建的原始人姿势行为之间的关联提供了基础。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智力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.