Genetic Ancestry of the Mexican Population: Diversity and Implications for Health Research

Mexico's population is often perceived, particularly in U.S. discourse, as genetically homogeneous. This misconception arises from a broader tendency to treat "Mexicans" or "Latinos" as a monolithic category, obscuring historical, cultural, and genetic differences. In fact, Mexico is a highly genetically diverse country. Centuries of admixture among Indigenous, European, and African populations have created complex ancestry patterns that vary by geography, sex-biased lineages, and fine-scale Indigenous substructure. Indigenous groups alone exhibit levels of differentiation comparable to those observed between continental populations, and these distinctions remain detectable in contemporary admixed Mexicans. Such diversity has tangible biomedical consequences: reported ancestry-associated variation in lung function, pharmacogenomic responses, and the discovery of the diabetes-associated SLC16A11 variant illustrate how studies in Mexicans can reveal genetic and health insights that may be invisible in more homogeneous populations. Implications extend well beyond Mexico. More than 37 million people of Mexican origin reside in the United States, forming the largest Latino subgroup, and their genetic ancestry mirrors that of populations in Mexico. Moreover, the European and African components of Mexico's admixture contribute to findings of broader applicability, underscoring that research in Mexico is not only relevant to Latinos but to human populations more generally. Recognizing Mexico's genetic diversity is therefore essential for building more accurate, inclusive, and equitable biomedical knowledge.