Collaborative Research: A Novel Genetic Database to Test Models of Human Origins

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The human genome holds clues to the mystery of human origins. With the recent completion of the first draft of the human genome sequence scientists are now in a position to examine patterns of variation across the entire genome in multiple human populations. Such an undertaking will facilitate an understanding of events that took place tens of thousands of years ago, and the better design of studies to map genes involved in human disease today. In this project, scientists from different fields within genetics (both theoretical and empirical population genetics) will gather new data and design novel analytical methods to answer long-standing questions in human evolution. One focus of this research is on the evolutionary relationships of "archaic" human groups (such as the Neanderthals in Europe and Homo erectus in Asia) to modern humans. Did archaic forms make any contribution to the contemporary human gene pool, or were Neanderthals and H. erectus completely replaced (without interbreeding) by modern humans as they expanded out of Africa within the last 100 thousand years? Did the ancestors of present day groups make the transition to modern form in a small, isolated part of Africa, or over a broader geographic range with genetic contributions from divergent populations. Another focus of this research is on human population growth. Although our current population size is more than 6 billion, the long-term average population size was probably substantially less than 1 million. When did human populations begin to expand dramatically in size? Was this growth associated with a particular event in human history, such as the advent of language or the invention of agriculture?This collaborative project seeks to address these and related topics by building a public database of DNA sequences from contemporary human populations, and by developing the computational tools necessary for the analysis of the data. DNA sequences will be otabined from 90 regions of the genome in representatives of six geographically diverse populations (e.g., three from sub-Saharan Africa and three from Eurasia), as well as representatives of humans closest living relatives, the great apes. Statistical and computational methods will be developed for rigorously testing the predictions of alternative hypotheses. The results of this project will be disseminated to a larger audience both through a public website and through an interdisciplinary symposium on human origins that will be organized in the fourth year. This research has several broader impacts. First, it will encourage debate and interaction among researchers from genetics, paleontology, archaeology, and historical linguistics. Second, the research will integrate research, teaching, and community outreach. Undergraduate students, graduate students, and post-doctoral fellows will be trained in a combination of theoretical and experimental skills. Programs are in place at both the University of Arizona and the University of Southern California for identifying promising candidates from underrepresented minorities and these students will be recruited to participate in the project. While training a new generation of anthropological geneticists this project will facilitate novel discoveries in human origins research.