Doctoral Dissertation Research: Examining the Energetics Hypothesis for the Origin of Hominid Bipedalism

这项研究提出了一个假设，即我们最早的原始人祖先向两足行走转变的性质。解决两足行走的起源是为了解决关于它对人类意味着什么的最基本的问题之一。尽管关于两足动物是否有助于定义人类家族存在争议，但很明显，成为两足动物是人类形态出现的关键第一步，先于所有其他主要的形态适应。从生物学和进化论的角度理解这对人类意味着什么，首先要理解两足动物的功能。这项研究分为两个阶段，旨在检验这样一种假设，即我们的中新世祖先转向两足行走是由于两足动物运动节省了能量。该项目解决了两个主要问题。首先，在黑猩猩中，两足移动时的能量成本与四足移动时的能量成本有多大的不同？回答这个问题将包括测量一组不同性别的成年黑猩猩在跑步机上两足和四足运动时的能量消耗。其次，目前测量自由活动的黑猩猩群体的白天旅行长度的方法是否系统性地低估了这些动物的实际每日旅行距离？这一问题将在一项为期6个月的实地研究中得到解决，该研究是在非洲乌干达基巴莱国家公园的Ngogo遗址对自由活动的黑猩猩习惯性种群进行的一项为期6个月的实地研究。将采用四种测量白天行程长度的方法，并将其与通过步速计数获得的测量结果进行比较，以获得自由活动的黑猩猩白天行程长度的可防御测量结果，并确定目前的方法低估实际每日行程距离的程度。这项研究的更广泛影响如下。该项目将为本科生助理提供在研究生一级进行科学研究方法的经验、参与和培训的机会。本科生助理将从加州大学农业、文学和科学(MURALS)本科生研究人员导师计划的学生成员中招聘。MURALS为代表不足的少数族裔学生提供资金，这些学生有兴趣在仍在本科生水平上获得研究生水平的研究经验。这项研究将在兽医学院和加州大学戴维斯分校人类学系之间建立重要的合作伙伴关系，为未来的跨学科研究奠定基础。该项目还将在加州大学和人类与黑猩猩共处(PACT)之间建立重要的合作伙伴关系，PACT是一个致力于照顾从医学研究和娱乐业退休的黑猩猩的非营利性组织。该项目将协助PACT进一步创建一个教育设施，向公众介绍黑猩猩的行为和保护需求。这项研究对整个社会的好处包括对现代医疗保健的几个领域的潜在贡献，包括运动医学、兽医和新兴的进化医学领域。此外，了解人类起源的愿望在人类社会中无处不在。这项研究将提供对这些起源的更深层次的理解。

This research addresses a hypothesis concerning the nature of the shift to bipedal locomotion in our earliest hominid ancestors. To address the origin of bipedalism is to address one of the most fundamental questions about what it means to be human. Though debate exists about whether bipedalism serves to define the human family, Hominidae, it is clear that becoming bipedal was the critical first step in the emergence of the human form, preceding all other major morphological adaptations. Understanding what it means to be human from a biological and evolutionary standpoint begins with understanding the functions of bipedalism. This study is a two-phase project designed to examine the hypothesis that the shift to bipedalism among our Miocene ancestors was due to energy savings associated with bipedal locomotion. The project addresses two primary questions. First, to what extent do energy costs during bipedal locomotion differ from energy costs during quadrupedal locomotion in chimpanzees? Answering this question will consist of measuring energy expenditure in a diverse set of adult chimpanzees of both sexes during bipedal and quadrupedal locomotion on a treadmill. Second, have current methods of measuring day journey length in free-ranging populations of chimpanzees systematically underestimated the actual daily travel distance of these animals? This will be addressed in a 6-month field study of day journey length in a habituated population of free-ranging chimpanzees at the Ngogo site in Kibale National Park, Uganda, Africa. Four methods of measuring day journey length will be employed and compared to measurements obtained through pace counting in order to obtain a defendable measure of day journey length for free-ranging chimpanzees and to determine to what extent current methods underestimate actual daily travel distance. The broader impacts of this research are as follows. This project will provide undergraduate student assistants with the opportunity for experience, participation and training in the methods of scientific research at the graduate level. Undergraduate assistants will be recruited from the student membership of the Mentorships for Undergraduate Researchers in Agriculture, Letters and Science (MURALS) program at the University of California. MURALS provides funding for under-represented and minority students interested in gaining experience doing graduate-level research while still at the undergraduate level. This research will establish important collaborative partnerships between the School of Veterinary Medicine and the Department of Anthropology at the University of California, Davis, laying the groundwork for future interdisciplinary studies. This project will also establish an important partnership between the University of California and People and Chimps Together (PACT), a non-profit organization dedicated to the care of chimpanzees retired from medical research and from work in the entertainment industry. This project will assist PACT in furthering the creation of an educational facility to introduce the public to the behavior and conservation needs of chimpanzees. The benefits of this research to society at large include potential contributions to several areas of modern health care including sports medicine, veterinary medicine and the emerging field of evolutionary medicine. Moreover, the desire to understand our origins is ubiquitous in human society. This research will provide a deeper understanding of those origins.