1Department of Anthropology, University of New Mexico, Albuquerque, NM 87131, 2Division of Epidemiology and Biostatistics, Department of Internal Medicine and University of New Mexico Cancer Center, University of New Mexico, Albuquerque, NM 87131
Friday 5:00-5:15, Parlors
We examined population genetic substructure among New Mexican Hispanics (NMH) to further our understanding of the admixture process and its health and social implications. Our data consisted of 251 microsatellite loci assayed in 103 NMH in the Cancer Genetics Network (NCIU24 CA78174, PI Marianne Berwick) and in 29 French and 25 Mexican Pima from the CEPH-HDGP. We used maximum likelihood methods to estimate European and Native American ancestry proportions in the NMH individuals. For each NMH, we tested three null hypotheses: 1) genetic ancestry is 100% European, 2) genetic ancestry is 0% European, and 3) genetic ancestry is 76% European (average for NMH sample). The mean European ancestry estimate of 76% is higher than that reported for any other Hispanic population in the U.S. and Mexico (published averages range from 38-63%). We rejected Hypotheses 1 and 2 for all 103 individuals. We rejected Hypothesis 3 for 20 of 103 individuals. Ten of these 20 exceeded the population average, while ten fell below the population average. This result rules out a simple, one-time admixture event in New Mexico. Six of the ten who exceeded the average reported one non-Hispanic White parent, while eight of the ten who fell below the average self-identified as ‘Mexican’. These results provide a window into the types of population processes that shape human biological diversity, and they attest to the ephemeral nature of ethnic identity and the heterogeneous nature of Hispanic populations at both the between- and within-group level.
Funding source: UNM Research Allocation Committee