Date of Award

7-12-2024

Author's School

Graduate School of Arts and Sciences

Author's Department

Anthropology

Degree Name

Doctor of Philosophy (PhD)

Degree Type

Dissertation

Abstract

Bipedalism is a key human adaptation, making its evolution a central topic in biological anthropology. To meet the mechanical demands of bipedalism, the human foot evolved significantly. This research examines the evolutionary patterns and selective histories that have shaped foot evolution in hominins and great apes. Additionally, it analyzes the environmental conditions under which hominin feet evolved. The results suggest that the last common ancestor of humans and chimpanzees exhibited adaptations for terrestrial heel strike plantigrady and vertical climbing. Early hominin foot adaptations involved eversion and midfoot stability. The Paranthropus and the Australopithecus africanus + A. sediba clades revealed arboreal traits, suggesting better adaptations for arboreal life. Most traits followed the Brownian motion model, influenced by random processes. However, a critical subset of traits linked to joint stability followed the Ornstein-Uhlenbeck model. Moreover, the results suggest that bipedalism initially evolved in a dry environment. Dense vegetation and forest habitat likely played a crucial role in shaping bipedal evolution at subsequent nodes. Finally, ecological flexibility allowed key traits to persist across varied environments. This research emphasizes the importance of considering phylogenetic and environmental contexts in studying the evolution of bipedalism.

Language

English (en)

Chair and Committee

David Strait

Committee Members

Michael Landis; Richard Smith; Terrence Ritzman; Thomas Cody Prang

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