Doctoral Dissertation Research: The shape of hands and feet and the transition to upright walking

博士论文研究：手脚的形状以及直立行走的过渡

• 批准号: 2316552
• 负责人: Douglas Boyer
• 金额: $ 3.42万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2316552&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; shape; hands

Researchers have long hypothesized that the transition to upright walking on two legs (bipedalism) in humans was facilitated in our distant, non-primate ancestors by an increased reliance on the hind limb while walking on four legs. As a pivotal part of our evolutionary trajectory, it is proposed that once our ancestors’ hands were freed from involvement in walking, they were able to be used for other purposes such as tool use, grooming, and carrying. Previous research on the transition to upright walking in human ancestors has largely focused on non-human primates. To better understand whether the relationship between reliance on hind limbs while walking on four legs and the emergence of bipedalism is unique to human evolution, this doctoral dissertation research project casts a broad comparative net and includes a comparison between primates and carnivores. This project offers opportunities for undergraduate students to gain exposure to STEM-discipline focused ideas and research questions, and to receive transferable technical training and experience.This project tests the hypothesis that the development of a dominant limb is associated with morphological and functional diversification of the non-dominant limb. This project tests this and related hypotheses in three ways: (1) testing if increased reliance on the hind limb allows for diversification of the forelimb by tracking co-variation of hand and foot bones across an expansive sample of extant primate taxa; (2) assessing the effect of limb dominance on functional diversity in an independent mammalian clade (Carnivora) that is thought not to have been characterized by hind limb dominance during its early evolution; and (3) conducting a large-scale comparison of primate and mammalian carnivoran hand and foot bones to track rates of shape variation across both orders. Understanding the ways that the bones of the hands and feet of these groups have evolved helps to elucidate a better understanding of the underlying processes that took place in primates millions of years ago shaping the trajectory of modern human evolution. The broad perspective used in this study is innovative and informative for better understanding of the evolution of bipedalism in humans.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.

研究人员长期以来一直认为，在我们遥远的非灵长类祖先中，四足行走时对后肢的依赖程度增加，促进了人类向两足直立行走（两足行走）的转变，这是我们进化轨迹的关键部分。 ，有人提出，一旦我们祖先的双手不再参与行走，它们就能够用于其他目的，例如使用工具、梳理毛发和携带东西，之前的研究主要集中在人类祖先向直立行走的转变上。在为了更好地了解四足行走时对后肢的依赖与两足动物的出现之间的关系是否是人类进化所独有的，这个博士论文研究项目进行了广泛的比较，包括对灵长类动物和食肉动物之间的比较。该项目为本科生提供了接触 STEM 学科重点思想和研究问题的机会，并接受可转移的技术培训和经验。该项目测试了优势肢体的发育与形态和功能相关的假设。该项目通过三种方式测试这一点和相关假设：（1）通过跟踪广泛样本中手部和足部骨骼的共同变化来测试增加对后肢的依赖是否允许前肢的多样化。现存灵长类类群的研究；（2）评估独立哺乳动物分支（食肉目）的肢体优势对功能多样性的影响，该分支被认为在其早期进化过程中不具有后肢优势特征；对灵长类动物和哺乳动物食肉动物的手骨和足骨进行大规模比较，以跟踪这两个目的形状变化率，了解这些群体的手骨和足骨的进化方式有助于更好地理解潜在的过程。数百万年前发生在灵长类动物身上的研究塑造了现代人类进化的轨迹，这项研究采用的广阔视角具有创新性和信息性，有助于更好地理解人类两足行走的进化。该奖项是 NSF 的法定使命，并被认为值得支持。通过评估利用基金会的智力优势和更广泛的影响审查标准。