Doctoral Dissertation Improvement: Fossil footprints and the dynamics of footprint formation: Implications for the evolution of human gait

两足行走是现代人类的一种基本行为，但关于它在我们已经灭绝的祖先身上进化的许多问题仍然没有答案。研究骨骼化石解剖学的古人类学家以许多不同的方式分析了这些数据，但在两足动物何时以及如何进化的问题上得出了相互矛盾的结论。要解决这场正在进行的争论，需要新的方法。博士生凯文·哈塔拉(乔治华盛顿大学)在布莱恩·里士满博士的指导下，将通过分析一种新型的“化石行为”数据，以最近发现的古人类足迹的形式，寻求一种绕过这些问题的新方法。随着上更新世不同时期化石脚印样本的不断增加，这些数据可以用来研究人类足部解剖和两足动物运动的进化。然而，在科学家能够利用存储在这些脚印中的信息之前，需要确定如何在脚印中记录解剖和步态。这项研究将使用实验生物力学来研究足迹形成的动态过程，并将这一知识应用于坦桑尼亚莱托利、肯尼亚伊莱雷特和坦桑尼亚恩盖尔塞罗的古人类足迹化石的分析。这些分析将直接检验这样一个假设，即现代人在解剖和功能上对两足行走的适应分别出现在370万年、150万年和12万年前的古人类身上。通过与罗格斯大学/肯尼亚库比福拉野外学校的合作，该项目包括对来自肯尼亚、南非和美国的本科生进行广泛的培训。结果将通过出版物和会议向科学受众展示，并通过与史密森国家自然历史博物馆人类起源计划的持续合作向公众展示。肯尼亚国家博物馆将开发一个新的档案系统，使学生和其他研究人员能够访问该项目期间产生的化石足迹的原始三维扫描。

Bipedalism is a fundamental modern human behavior yet many questions about its evolution in our extinct ancestors remain unanswered. Paleoanthropologists studying fossilized skeletal anatomy have analyzed these data in many different ways, only to arrive at conflicting conclusions regarding when and how bipedalism evolved. New approaches are necessary to resolve this ongoing debate.Doctoral student Kevin Hatala (The George Washington University), under the supervision of Dr. Brian Richmond, will pursue a novel approach that circumvents these problems by analyzing a new type of 'fossilized behavior' data, in the form of recently discovered fossil hominin footprints. With a growing sample of fossil footprints from different times throughout the Plio-Pleistocene, these data can be used to investigate the evolution of human foot anatomy and bipedal locomotion. Before scientists can take advantage of the information stored in these footprints, however, there is need to determine how anatomy and gait are recorded in footprints. This study will use experimental biomechanics to investigate the dynamic process of footprint formation, and will apply this knowledge to the analysis of fossil hominin footprints from Laetoli, Tanzania; Ileret, Kenya; and Engare Sero, Tanzania. These analyses will directly test the hypothesis that modern humans' anatomical and functional adaptations for bipedal locomotion were present in hominins at 3.7, 1.5, and 0.12 million years ago, respectively.Through collaboration with the Rutgers University/National Museums of Kenya Koobi Fora Field School, this project involves extensive training of undergraduates from Kenya, South Africa, and the US. Results will be presented to scientific audiences through publications and conferences, and to the public through ongoing collaborations with the Smithsonian's National Museum of Natural History Human Origins Program. A new archival system will be developed at the National Museums of Kenya, allowing students and other researchers to access the original three-dimensional scans of fossil footprints generated during this project.