Bipedalism
Bipedalism is a hallmark of humans, and as such has been the focus of extensive paleoanthropological research. Numerous studies have shown that many of the characteristics unique to human body form can be explained as adaptations for efficient bipedal locomotion. However, there also appears to be some degree of plasticity in skeletal form as it relates to bipedalism, with aspects of knee shape in particular being a response to the biomechanical stresses of upright walking.
The peculiar dependence of knee form on juvenile locomotor behavior speaks to the value of considering the evolution of bipedalism from an ontogenetic prospective. Under the direction of Dr. Tim Weaver of UC Davis, and Dr. Zeray Alemseged of the University of Chicago, graduate student Peter Stamos is studying human, extant ape, and early hominin knee growth trajectories. Utilizing three-dimensional geometric morphometrics, the study will consider juvenile knee form, knee ontogeny, and the interplay between ontogeny and biomechanical stress in an attempt to make inferences about the locomotor behavior of early hominins.
Life History
Life history theory is concerned with the pace and ways in which an organism allocates resources to growth, development, and reproduction. The study of life history is important in paleoanthropology because the life history pattern exhibited by modern humans is unique among primates. In particular, modern humans are characterized by an extended juvenile period, large adolescent growth-spurt, and incredibly long post-reproductive life-span. These characteristics, which are typical of a “slow” life-history, are contrasted by a young weaning age and short interbirth interval in humans, characteristics more typical of animals with “fast” life-histories. Because of these unique aspects of human life histories, and the implications they have for the development of human cognition and culture, trying to decipher the evolutionary development of human life history is of paramount interest to anthropologists.
Peter Stamos' research into primate locomotor ontogeny aims to give insight into the life history patterns of our early ancestors. Namely, the research will attempt to determine when locomotor independence was achieved in young Australopithecus afarensis individuals.
Behavior
Stone artifact archaeology has revealed important insights into the evolution of early hominin behavior. This research has shown that early hominins were selective in the kinds of stone they used to make tools, transported their tools around their environment, and manufactured their tools following certain guiding principles all for at least the last 2.5 million years. Patterns in these technological behaviors provide essential insights into fundamental evolutionary problems such as the appearance of stone tool making, the origins of the genus Homo, and the earliest hominin dispersals into Eurasia.
The earliest sites found in Eurasia show that the technological strategies that early hominins were utilizing were similar to some of the earliest strategies evidenced from Africa. However, the environments that these early hominins encountered were climatically and ecologically different then those they left. Current research aims at understanding how these old strategies allowed for early hominins to adapt to new and changing environments and the effect that these environments had on those strategies through time.
Graduate student Corey Johnson's research into the archaeological record of the Nihewan Basin aims to give insight to how early hominins ca. 1.2 million years ago made stone tools in what is today northern China. This research will attempt to assess and explain variability in technological strategies at Nihewan during this time to understand paleoecological effects on early hominin behavior.
