Functional Anatomy of the Knee and Development-Implications for Interpreting Early Hominin Locomotion

膝关节的功能解剖学和发育——解释早期古人类运动的意义

• 批准号: 1506280
• 负责人: Eric Delson
• 金额: $ 20.25万
• 依托单位: American Museum Natural History
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-10-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1506280&HistoricalAwards=false
• 关键词: Functional; Anatomy; Knee; Development; Implications

This project supports the training and education of a Mexican American Postdoctoral Fellow, an under-represented minority in science and especially paleoanthropology. As a Chicana and first generation college graduate, the Fellow is personally committed to broadening participation of under-represented individuals in STEM fields. The research project explores bipedalism in humans. Walking on two legs is a defining feature of the human lineage, and yet major questions remain about the origin and evolution of human gait. Bipedalism evolved early in the human lineage, possibly as early as six million years ago; however, major debate has persisted over whether the earliest hominins walked essentially like modern humans do today, or whether various hominin species differ in their gait biomechanics. The recent discovery of an unusually complete, 2 million year old skeleton belonging to Australopithecus sediba has inspired new inquiry into the development and function of the hominin lower limb. In particular, recent interpretations of Au. sediba have refueled the debate as to how different species of australopiths may have varied in their form of bipedalism. The only way to directly test those hypotheses relies on examining aspects of the skeleton are sensitive to biomechanical demands during growth, and thus provide evidence of the biomechanics of gait during growth. However, little is currently known about how gait biomechanics influences the development of the lower limb. This project combines experimental, ontogenetic, and comparative approaches to interpret and reconstruct early hominin bipedalism. First, the effect of locomotor regimes (vertical climbing, pedal grasping canopy climbing, and wheel-running) on lower limb morphology are studied in a mouse experimental model, addressing skeletal plasticity of the femur and tibia. In running this project, the Fellow recruits minority students to be trained as assistant researchers through minority student organizations at GWU such as the Bouchet Society. The Fellow continues to present her research to children through outreach programs targeting low-income and minority students interested in science. This relies on previous experiences implementing age-appropriate activities, piloted during graduate school. Other efforts to improve public understanding of science include engaging broad audiences through the Smithsonian Institution's National Museum of Natural History's outreach programs (e.g., Scientist Is In, Human Origins Today (HOT) Topics), based on presentations originally developed for the NC Museum of Natural Sciences during the final year of her dissertation. The Fellow continues to be active in Graduate Women in Science, supporting other female scientists across STEM fields as well as coordinating outreach and volunteer opportunities for these women.Intellectual Merit: The proposed project advances our understanding of how and when our modern style of upright, bipedal gait evolved. The current paradigm views all early human ancestors and relatives as essentially the same, when in fact there may be considerable adaptive diversity in the early phase of human evolution. This project therefore has the potential to transform the current paradigm in paleoanthropology, and integrates experimental, developmental, and comparative data to achieve a more rigorous understanding of the functional significance of knee anatomy in humans. The experimental component provides the context for interpreting the results of a comprehensive ontogenetic primate comparative study, which examines whether developmental trajectories are correlated with behavioral changes throughout development, and addresses whether deviations from the general mammalian and primate pattern of epiphyseal fusion are correlated with specialized locomotion. Finally, lower limb fossils belonging to early Homo erectus and other early hominin species are included to test and advance hypotheses about the functional significance of developing morphology in light of the aforementioned experimental and ontogenetic results.

该项目支持墨西哥裔美国博士后研究员的培训和教育，该博士后研究员是科学领域，特别是古人类学领域代表性不足的少数群体。作为一名奇卡纳人和第一代大学毕业生，该研究员个人致力于扩大 STEM 领域代表性不足的个人的参与。该研究项目探索人类的两足行走。两条腿行走是人类谱系的一个决定性特征，但关于人类步态的起源和进化的主要问题仍然存在。两足行走在人类谱系的早期就已进化，可能早在六百万年前。然而，关于最早的古人类是否基本上像今天的现代人类一样行走，或者不同的古人类物种的步态生物力学是否不同，一直存在重大争论。最近发现的一具异常完整、具有 200 万年历史的南方古猿源泉骨骼激发了人们对古人类下肢发育和功能的新研究。特别是最近对 Au 的解释。源泉种进一步引发了关于不同物种的南方古猿在两足行走方面可能有何不同的争论。直接检验这些假设的唯一方法依赖于检查骨骼对生长过程中生物力学需求敏感的方面，从而提供生长过程中步态生物力学的证据。然而，目前人们对步态生物力学如何影响下肢发育知之甚少。该项目结合了实验、个体发生和比较方法来解释和重建早期古人类的双足行走。首先，在小鼠实验模型中研究了运动方式（垂直攀爬、踏板抓紧顶篷攀爬和车轮奔跑）对下肢形态的影响，解决了股骨和胫骨的骨骼可塑性问题。在运行这个项目时，研究员招募少数族裔学生，通过布歇协会等乔治华盛顿大学的少数族裔学生组织，接受培训作为助理研究人员。该研究员继续通过针对对科学感兴趣的低收入和少数族裔学生的外展项目，向儿童展示她的研究成果。这依赖于以前在研究生院期间试点实施适合年龄的活动的经验。提高公众对科学理解的其他努力包括通过史密森学会国家自然历史博物馆的外展计划（例如，科学家在、当今人类起源（热门）主题）吸引广大观众，这些计划基于最初为北卡罗来纳州自然历史博物馆开发的演示文稿她论文最后一年的科学。该研究员继续积极参与科学领域的女性研究生活动，支持 STEM 领域的其他女性科学家，并为这些女性协调外展和志愿者机会。 智力优点：拟议的项目增进了我们对现代风格的正直、双足步态进化了。当前的范式认为所有早期人类祖先和亲戚本质上都是相同的，而事实上，在人类进化的早期阶段可能存在相当大的适应性多样性。因此，该项目有可能改变古人类学的当前范式，并整合实验、发育和比较数据，以更严格地理解人类膝关节解剖学的功能意义。实验部分为解释全面的灵长类个体发育比较研究的结果提供了背景，该研究检查发育轨迹是否与整个发育过程中的行为变化相关，并解决一般哺乳动物和灵长类骨骺融合模式的偏差是否与专门的运动相关。最后，包括属于早期直立人和其他早期人科物种的下肢化石，以根据上述实验和个体发生结果测试和提出关于发育形态的功能意义的假设。