Doctoral Dissertation Research: The evolutionary history of the human and ape knee

Dartmouth College, Hanover NH

Investigators

Abstract

Bipedalism, or upright walking, is a defining characteristic of modern and ancestral humans. It was one of the earliest defining traits of the human lineage and played a significant role in shaping our behavior and anatomy. To better understand the evolution of bipedalism, many researchers have studied the pelvis, foot, and vertebral column, all of which play a part in bipedal movement; somewhat less attention has been paid to the knee joint despite its essential role during human bipedalism. This doctoral dissertation research project studies the movement and anatomy of the knee joint and the results of the research can be relevant both for understanding the origins and evolution of human upright walking, as well as functional anatomy of the knee joint. Given the high frequency of knee replacement in the U.S., this offers one key example of how evolutionary understandings can potentially inform medical perspectives, and approaches to injury prevention and intervention. The goal of this research is to investigate the relationship between knee joint anatomy and locomotor function in modern primates to help understand the pattern of locomotor behavior in hominin and hominoid fossil records. This project is carried out in three complementary phases that combine modern primate kinematic data, modern primate skeletal data, and data collected from the distal femur, proximal tibia, and patella of fossil hominins and hominoids. These phases include collection of kinematic data on gait and degree of knee extension in living primates as they walk bipedally, skeletal sample measurements in individuals of the same species from museum collections, and application of results of the first two phases to interpret anatomy in the human and ape fossil record. Ultimately the results of this research can inform paleoanthropological perspectives regarding the body form from which modern human bipedalism evolved. 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.