Doctoral Dissertation Research: Descent Locomotion Behavior in Primates

灵长类动物与其他哺乳动物的不同之处在于它们抓握的手和脚，以及指甲而不是爪子。这些解剖特征被认为帮助了最早的灵长类动物在细小的树木末端树枝上导航。然而，缺少爪子也可能导致了在无法抓取的大树上导航时的不同运动(运动)行为。这个博士论文项目将研究不同的灵长类和非灵长类哺乳动物，以更好地了解运动随年龄的变化，以及对不断变化的环境的反应。这些发现有助于阐明灵长类种群中运动进化和生活史之间更广泛的相互作用模式。该项目将支持从K-12到研究生阶段的学生培训和辅导。该项目产生的数据将用于推广课程计划，展示如何将动物运动理解为简单的机器，用于北卡罗来纳州达勒姆至杜克大学的小学到中学年龄女孩的STEM教育计划，以及参加杜克狐猴中心年度公共推广日的所有年龄段的女孩。这个项目的目标是了解灵长类运动在选择或维持特定地方(例如细枝)运动的形态特化之间的权衡，同时仍然需要在更一般的环境(例如树、地面)之间移动。通过对八种灵长类动物和三种非灵长类哺乳动物下行运动和力学的比较分析，该项目通过实验改变支撑方向和大小，研究了随着环境条件变化而发生的行为变化。动物穿越越来越陡峭和厚实的支撑物的视频被拍到，据预测，灵长类动物将放弃头先走，转而选择其他行为，如跳跃、滑动和后退，以应对这些支撑物的生物力学挑战，而非灵长类哺乳动物将继续借助爪子头先走。比较样本的物种包括身体大小(0.06至3.5公斤)、肢体比例和行为特长的各种物种。在每个物种中，不同年龄的个体进行比较，以评估衰老如何影响树栖活动，这将是灵长类动物寿命不断延长的进化过程中遇到的一个关键挑战。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Primates are distinguished from other mammals by their grasping hands and feet, and nails instead of claws. These anatomical features are thought to have helped the earliest primates to navigate thin terminal branches of trees. However, the lack of claws may also have led to different locomotor (movement) behaviors for navigating large trees that could not be grasped. This doctoral dissertation project will study different primate and non-primate mammalian species to better understand locomotor changes with age, and in response to changing environments. These findings can help elucidate broader patterns of interaction between locomotor evolution and life history in the primate lineage. This project will support student training and mentoring at the K-12 through graduate levels. Data generated by this project will be used in an outreach lesson plan demonstrating how animal motion can be understood as simple machines for a STEM education program for elementary to middle school age girls in Durham, NC through Duke University, and for all ages attending annual public outreach days at the Duke Lemur Center. The goal of this project is to understand primate locomotor tradeoffs between selection for or maintenance of morphological specialization for movement in specific places (e.g. thin branches), while still needing to move through and between more general (e.g. trees, the ground) environments. Through comparative analysis of descending locomotion and mechanics in eight primate species, and three non-primate mammals, this project examines behavioral shifts in response to changing environmental conditions by experimentally modifying support orientation and size. Animals are filmed crossing increasingly steep and thick supports, and it is predicted that primates will abandon headfirst walking in favor of alternative behaviors, such as leaping, sliding, and rear-first descending in response to the biomechanical challenges of these supports, while non-primate mammals will continue to move headfirst with the aid of their claws. The comparative sample features species from a wide range of body sizes (0.06 to 3.5 kg), limb proportions, and behavioral specializations. Within each species, individuals of different ages are compared to assess how aging affects arboreal locomotion, which would have been a key challenge incurred during the evolution of increasingly long lifespans in the primate lineage.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.