Doctoral Dissertation Research: Behavioral reconstruction and the effects of habitual activity on the bone-muscle interface

骨骼可以提供许多关于运动和行为模式的线索，这种形式-功能关系使骨骼成为重建动物和人类进化史和过去行为的重要数据来源。在本论文项目中，骨骼对习惯性活动的反应将在小鼠和灵长类动物模型中进行研究，以提高我们对骨骼上的肌肉附着位点的理解，因为骨骼的这一特殊特征与功能的关系尚未完全了解。由活动引起的肠腔变化的实验证据将适用于各种学科，包括古人类学、生物学、临床医学和法医学。这项工作产生的所有图像将提供给其他研究人员，以促进进一步的跨学科研究。该项目将支持学生的研究经验，包括来自STEM研究中代表性不足的群体的学生，以及传统和在线公共科学推广活动。使用骨臼重建物种水平的运动模式和个体职业依赖于骨骼通过重塑和新骨的积累来响应机械负荷的前提。然而，最近的实验研究对假定的肌肉活动对骨骼的影响提出了质疑，并证明运动与骨窝表面的测量之间没有关系。该项目解决了有关依恋位点生物学的方法学问题，采用多层次的方法来评估是否以及如何将这些方法用于行为重建。本研究的第一个组成部分利用小鼠模型，控制和提高跑步和攀爬方案，以测试增加的活动是否会导致肌肉产生力量的能力，骨表面粗糙度，骨沉积率和/或骨横截面几何特性的相应增加。这一目标的结果将随后应用于现有的灵长类动物骨骼样本，以观察不同的运动模式如何与内骨发育相关。在悬吊、四足和两足灵长类动物中，选择与运动相关的胚胎，通过表面扫描和CT扫描，通过活动来检查依恋部位特征的模式。结合宏观骨表面及其潜在的机械环境的分析将提供一个全面的视图内钉区域。这些数据将为端部形态的解释提供经验基础，长期目标是利用这些结构对化石灵长类动物进行非破坏性行为重建。

The skeleton can provide many clues about movement and behavior patterns, and this form-function relationship makes bone an important source of data for reconstructing the evolutionary history and past behaviors of animals and humans. In this dissertation project, the response of bone to habitual activity will be investigated in murine and primate models to improve our understanding of entheses (muscle attachment sites on bone), because the relationship of this particular feature of bone to function is not fully understood. Experimental evidence of enthesis change due to activity will be applicable across a variety of disciplines, including paleoanthropology, biology, clinical medicine and forensic science. All images generated as a result of this work will be made available to other researchers in order to promote further interdisciplinary research. The project will support student research experiences, including for students from groups underrepresented in STEM research, and both traditional and online public science outreach activities.The use of entheses to reconstruct species-level locomotor patterns and individual occupation relies on the premise that bone responds to mechanical loading with remodeling and the accumulation of new bone. However, recent experimental studies have questioned the assumed effect of muscle activity on bone and demonstrated no relationship between exercise and measures of the entheseal surface. This project addresses the methodological issues concerning attachment site biology, taking a multilevel approach to assess if and how entheses can be used for behavioral reconstruction. The first component of this study utilizes a murine model with controlled and elevated running and climbing regimes to test whether increased activity results in corresponding increases to muscle force-generating capacity, bone surface roughness, bone depositional rate, and/or bone cross-sectional geometric properties. The results of this aim will then be applied to an existing sample of primate skeletons in order to observe how different locomotor modes relate to enthesis development. A selection of locomotor-relevant entheses in suspensory, quadrupedal and bipedal primates will be examined with surface and CT scans for patterns of attachment site characteristics by activity. A combined analysis of the macroscopic bone surface and its underlying mechanical environment will provide a comprehensive view of the enthesis region. These data will provide an empirical foundation for the interpretation of enthesis morphology, with the long-term goal of enabling non-destructive behavioral reconstruction on fossil primates using these structures.