Located primarily in northwestern Chihuahua, Mexico, the Casas Grandes culture was similar to other cultures located within in the North American Southwest. However, by AD 1200, it had metamorphosed. New forms of ritual architecture, burial practices, ceramic vessels, and trade patterns attest to drastic changes in daily life for the individuals who lived in Casas Grandes. The appearance of Aztatlan (northwest Mexican) and Mimbres (New Mexican) artifacts and symbolism during the Medio period (AD 1200-1450) have led to questions about their origins. Some researchers argue that immigration from one or both of these regions led to marked cultural change over time. Alternatively, local inhabitants of the Casas Grandes culture may have adopted foreign features into their lives. Were new features the result of migration or simply the exchange of ideas and goods? Under the supervision of Dr. Osbjorn Pearson, Sophie Kohn will explore genetic relationships between the pre-Hispanic occupants of Mimbres, Casas Grandes, and Aztatlan. Measurements of the teeth and shape variants of the skull and teeth (non-metric traits) are genetically controlled attributes of the skeleton that can be used to trace genetic relationships between populations. These attributes will be used to identify the presence or absence of a migration at the beginning of the Medio period. If a migration did occur, then the traits will be used to identify the source population of the migrants. This research is important for several reasons. First, there is evidence of contact between Mesoamerica and the US Southwest that extends several thousand years into the past. This research will contribute information on the manner of contacts between these two areas, whether by direct migration or trade. In a related vein, it explores the role that migration plays in cultural change over time. By identifying or ruling out the presence of migration, this study will provide information on the impact that these different forms of contact can have on cultural evolution. Second, artifact based interpretations of population structure, migration and trade are common in the Greater Southwest. However, such studies rely on indirect evidence for population movements. Biological data provide an alternative way to examine relationships because they can provide direct evidence for population movements. Third, while interest in northern Mexico has increased over the past ten years, the region is still drastically understudied. This research will provide vital information on the genetic composition of the Casas Grandes culture, and its relationships with external populations. Beyond impacting the US research community, this research will aid the Mexican National Institute of Anthropology and History (INAH) by contributing to the first computerized inventory of the skeletal material from Casas Grandes. As a cooperative effort between the University of New Mexico (UNM) and INAH, this work will foster good relations for future research. Continued research in Chihuahua will help the Mexican government promote the UNESCO world heritage site of Paquime and increase tourism to the area. For the Co-PI, this research will provide invaluable experience in data collection and analysis. Information gleaned from the dissertation will be disseminated by providing skeletal data and a copy of the dissertation to all institutions that house skeletal collections. Also, the Co-PI will publish a series of papers in scholarly journals to widely circulate results.