Collaborative Research: Measuring leaping performance, evaluating its anatomical correlates, and reconsidering the importance of leaping in primate origins and early evolution

灵长类动物在环境中表现出各种各样的适应性，关于这些运动模式的假设长期以来一直在灵长类动物起源模型中发挥着核心作用。在这个项目中，研究人员将使用一套综合的分析技术来(1)探索“跳跃相关”骨骼特征与跳跃性能的相关性；(2)评估灵长类动物化石记录中由此产生的相关性的进化意义。这种方法旨在提供有效的证据，能够支持或反驳早期灵长类动物运动特征为强大的树跳选择的假设。利用杜克狐猴中心和克利夫兰城市公园动物园（CMZ）的研究设施，本研究将通过提供19种现存灵长类动物跳跃行为的定量生物力学数据，为早期灵长类动物进化过程中跳跃行为的相关性做出贡献。该项目将通过东北俄亥俄医科大学和杜克大学的高中研究实习生的参与，以及通过在当地STEM学院教授灵长类动物运动生物力学的短期课程和在CMZ、杜克大学达尔文日和北卡罗来纳自然科学博物馆举办的公共科学活动，加强K-12教育和推广工作。该项目还将为本科生、女研究生和一名博士后提供研究培训和机会。长期以来，关于灵长类动物祖先运动的不同假设引发了关于灵长类动物起源中主要选择压力的激烈争论。最近的古生物学分析表明，在早期灵长类动物进化过程中，对改进跳跃的选择尤为重要。关于灵长类祖先古生物学的假设受到对灭绝谱系中形态变异的功能意义的有限理解的限制，因为化石目前只能提供关于行为能力的不精确线索。形态学和运动表现之间需要强有力的相关性，以便从化石揭示的解剖学转变中更精确地推断灵长类起源期间的运动转变。幸运的是，跳跃的生物力学相对容易表征，使其成为一种特别容易研究的运动行为。本研究分为两个具体目标。研究人员将使用高速视频和力板来研究现存灵长类动物、松鼠和树鼩的跳跃表现。这些数据将与形态测量数据集相结合，以检验跳跃性能变化与骨骼形态变化有关的假设。（AIM 2）在对跳跃行为的功能形态学有了更深入的了解之后，研究者将使用系统发育比较分析和进化模型来研究跳跃在冠类灵长类动物起源及其随后进化过程中的选择性重要性。这种双管齐下的方法将基于对灵长类动物“跳跃”形态的转化功能特异性的解释，允许评估灵长类动物化石记录中的形态变化如何定量地影响跳跃表现，并为长期以来关于灵长类动物起源的生态背景的争论提供信息。本项目由国家自然科学基金sbe - bcs -生物人类学和bio - ios -生理机制与生物力学项目联合资助。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。

Primate species display a diverse range of adaptations for moving through their environments, and hypotheses about these locomotor patterns have long played a central role in models of primate origins. In this project, the investigators will use an integrative set of analytical techniques to (1) explore the correlation of “leaping related” skeletal traits with leaping performance and (2) assess the evolutionary implications of the resulting correlations in the primate fossil record. This approach is designed to provide validated evidence capable of supporting or refuting the hypothesis that selection for powerful arboreal leaping characterized early primate locomotion. Utilizing research facilities at the Duke Lemur Center and the Cleveland Metroparks Zoo (CMZ), this study will contribute to the debate on the relevance of leaping behavior during early primate evolution by providing quantitative biomechanical data on leaping performance in 19 species of extant primates. The project will enhance K-12 education and outreach via the involvement of high school research interns at Northeast Ohio Medical University and Duke University, as well as public outreach efforts through the teaching of a short course on primate locomotor biomechanics at a local STEM academy and public science events at the CMZ, Duke University’s Darwin Day, and the North Carolina Museum of Natural Science. The project will also provide research training and opportunities for undergraduates, female graduate students, and a postdoctoral fellow. Differing hypotheses about ancestral primate locomotion have long generated strong debate about the predominant selective pressures acting during primate origins. Recent paleontological analyses have been interpreted to suggest that selection for improved leaping was particularly critical during early primate evolution. Hypotheses about the paleobiology of ancestral primates are constrained by a limited understanding of the functional significance of morphological variation in extinct lineages, as fossils currently provide only imprecise clues about behavioral capacity. Robust correlations between morphology and performance are needed to more precisely infer locomotor transitions during primate origins from the anatomical transformations revealed by fossils. Fortunately, leaping biomechanics are relatively easy to characterize, making this a particularly tractable locomotor behavior to study. This research is organized into two specific aims. (AIM 1) Investigators will use high-speed video and force plates to study leaping performance in a diverse sample of extant primates, squirrels, and treeshrews. These data will be combined with morphometric datasets to test hypotheses relating variation in leaping performance to variation in skeletal morphology. (AIM 2) Armed with a deeper understanding of the functional morphology of leaping performance, investigators will use phylogenetic comparative analyses and evolutionary modeling to investigate the selective importance of leaping at the origin of crown primates and during their subsequent evolution. This two-pronged approach will ground interpretations of primate “leaping” morphology with transformational functional specificity, permitting assessment of how morphological changes in the primate fossil record quantitatively affected leaping performance and informing long-standing debates on the ecological context of primate origins. This project is jointly supported by the NSF SBE-BCS-Biological Anthropology and BIO-IOS-Physiological Mechanisms and Biomechanics programs.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.