Doctoral Dissertation Research: Cultural Factors and Y-Chromosome Variation in the Yanomamo

Pennsylvania State Univ University Park, University Park PA

Investigators

Abstract

Small-group social structure, cultural practices, and demography have shaped the amount of human genetic variation throughout most of human history. This study examines Y-chromosome variation among a group of native South Americans, the Yanomamo. This population provides a model of the demographic history of early human society (though this is by no means perfect, as the Yanomama, like all groups, have been affected by their broader context, including agriculture and contact - often detrimental contact - with the outside world). Still, small group dynamics have been the most important factor shaping modern human genetic diversity. This study uses genetic markers on the Y chromosome, which is unique to males, in order to understand the evolutionary patterns that have lead to the low variability found on the human Y chromosome. Specifically, this study will examine how differential reproductive success among males and the demographic processes of population growth and village social structure effect the distribution of Y-chromosome variation. In addition, this study will examine how cultural contact has changed the native distribution of Y-chromosome variation. This study uses and builds on the work of cultural anthropologists who precisely documented village histories, genealogies and demographic patterns during fieldwork conducted over the last three decades. The data generated by this project will be combined with this earlier data as well as with the data from other current studies on mitochondrial and autosomal DNA to produce one of the most comprehensive studies of a tribal population in the history of anthropology. The overall result will be a deeper understanding not only of the genetic patterns of the Yanomamo, but also of the processes that have shaped the genetic variation of all human beings. In particular, this study will examine aspects of the way that social and cultural factors affect human variation in the small-group circumstances in which most human populations throughout our history as a species have lived.