Publication Date

Summer 7-1-2019

Abstract

This dissertation focuses on a regional population, New Mexicans of Spanish-speaking descent (NMS), to explore the nature of identity-related substructure in admixed populations and its implications for research and policymaking. We looked at the relationship between ethnic/ethnoracial identity and genomic ancestry in NMS in two studies. In the first, we collected genomic ancestry data using 270 autosomal microsatellites in 98 New Mexicans who self-identified as Hispanic or Latino and provided more detailed information on their ethnoracial identities. We tested for genetic substructure in this sample along with 13 other admixed samples from the Americas. The New Mexican sample showed evidence of genetic substructure linked to self-identification in two main groups: those who had recent ancestors from Mexico, who showed higher Native American ancestry, and those whose families had lived in New Mexico for many generations and emphasized their “Spanish” heritage, who showed higher European ancestry. Analyses of the additional admixed samples demonstrated genetic substructure to be nearly universal in admixed populations in the Americas and suggested that it may often be linked to social identity. We then interviewed 507 NMS and obtained data on ethnic identity, age, birthplace and historical ties to different regions. We estimated genomic ancestry in this sample using 291,917 single nucleotide polymorphisms (SNPs). We again found genomic ancestry differences between groups of NMS who used different ethnic identity nomenclature, and found corresponding differences in the birthplaces of participants and their recent ancestors and the time-depth of family ties to New Mexico between groups. Our data on ethnic identity were collected using both open-response and fixed-choice techniques. We found that the data obtained from both forms of questioning together provided richer information than either dataset alone, providing insights into important features such as strength of commitment to identity nomenclature. Broadly, this research emphasizes the importance of recognizing and accounting for identity-based substructure in admixed populations, which reflect historical patterns of migration, colonization, and cultural change. Failing to do so can confound research on the genetic basis of disease and on causes of variation in health outcomes and social inequality.

Keywords

Ethnic identity, genetic ancestry, New Mexico, Hispanic, admixture

Document Type

Dissertation

Language

English

Degree Name

Anthropology

Level of Degree

Doctoral

Department Name

Anthropology

First Committee Member (Chair)

Keith Hunley

Second Committee Member

Heather Edgar

Third Committee Member

Phillip Gonzales

Fourth Committee Member

Yann Klimentidis

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