NSF Award
1825403
Walking efficiently on two legs (bipedalism) is considered a defining characteristic of modern humans, and researchers have long strived to understand how, when, and why human bipedalism evolved. The discoveries of fossilized footprints made by living, moving individuals offer a promising source of data on hominin locomotion to complement what can be learned from fossilized skeletal remains. In this study, X-ray imaging, 3D animation, and computer simulation methods are developed and applied to understand formation of this bipedal record. Such foundational research is required to reconstruct foot anatomy and motion from fossil footprints, and to evaluate competing evolutionary hypotheses about bipedalism. The project represents an interdisciplinary collaboration between primarily undergraduate and major research institutions, with substantial training opportunities for undergraduate and graduate students. Student recruitment will focus on groups historically underrepresented in STEM fields. Results will be translated into pedagogical materials focused on the intersection of science and visual art, and the public will be engaged through museum and media science outreach.<br/><br/>Previous studies have developed methods for interpreting aspects of foot anatomy and motion from human footprints, but none have approached the problem mechanistically to understand the complex foot-substrate interactions through which footprints are formed. Direct observation of these interactions has not been possible because human feet and deformable substrates are both opaque, and contact areas are therefore hidden when a foot sinks to form a footprint. Here, biplanar X-ray, 3D animation, and computer simulation methods will be developed to visualize and analyze movement as individuals walk through substrates to create footprints. Direct mechanistic knowledge of foot-substrate interactions is potentially transformative for paleoanthropologists to extract anatomical and functional inferences from fossil human footprints and use these to test evolutionary hypotheses. Further, new imaging and analysis techniques are readily transferrable to other organisms, and may transform other approaches across animal biomechanics.<br/><br/>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.
