Environmental Dynamics and the Evolution of Human Adaptability

Adaptability refers to an organism's ability to endure environmental change, to spread to new habitats, and to respond in novel ways to its surroundings - all of which typify the living human species, Homo sapiens. The main objective of this project is to investigate the emergence of human adaptability in the dynamic settings that characterized the past four million years. Human origins during this period involved a lengthy transition from small apelike populations confined to equatorial regions of Africa to a worldwide, highly diverse human species capable of altering its surroundings in unprecedented ways. In this project scientists from diverse fields (anthropologists, paleontologists, geologists, and environmental scientists) will gather new data to further our understanding of how major human adaptations evolved in response to ancient environments.

The period of human ancestry was typified by a very complex sequence of environments, including progressive change (global cooling during the ice ages), large climate oscillation (repeated change between glacial-interglacial and arid-moist conditions), and times of stability. It is not yet known, however, whether early technological change, brain enlargement, geographic dispersal, development of symbolic behavior, among other key events in human prehistory, coincided with periods of directional change, strong fluctuation, or stability. This project will compare detailed environmental, fossil, and archeological records in Africa and East Asia in order to test when, where, and why human ancestors developed a greater ability to adjust to new surroundings and to modify their habitats.

This project will include the first comparative analysis of fossil and environmental records from both Africa and East Asia, funded by NSF and the Chinese Academy of Sciences. Excavations and laboratory analysis in the two distant regions offer a novel opportunity to explore the connection between environmental and evolutionary change and the common prehistory of the two regions. Project research teams will collect data to measure change in early human behavior (from archeological sources) and in anatomy (from the fossil record). Change in past animal communities and ecosystems will also be studied to provide a context in which to judge the development of uniquely human strategies of interaction with the environment. Environmental research teams will use state-of-the-art techniques to examine the nature and rate of global change, evident in the ocean record, and of local change in areas where humans emerged and spread.

The project also includes geneticists who will experimentally evaluate the possible genetic processes by which adaptability evolves. This research will investigate the model organism C. elegans (nematode), and will test for mechanisms of genetic change that favor adaptive flexibility to emerge in response to experimental sequences of environments. The combined components of this project are thus designed to stimulate communication across experimental and historical approaches within and across the natural and social sciences. Through workshops, conferences, and a publicly accessible website and database, our project seeks to unify fields that only together can address an unanswered scientific question, the origin of adaptability in humans and other organisms. The broader impacts f this research will include public outreach through the web, museum exhibitions, distance-learning curricula, and opportunities for student internships.