Genetic Structure of the Maya in Guatemala: Perspectives on the Population History of the Maya using mtDNA and Y-chromosome Markers

The Maya are a diverse ethno-linguistic group with a rich history and an important historical role in Latin America. While they are often treated as a homogenous group among biologists and physical anthropologists, given their wide geographic occupation, long history, linguistic variability, and cultural variation, there likely exists a quantifiable difference among the Maya linguistic and cultural groups. This dissertation tests the efficacy of treating the Maya populations as a genetically homogenous group genetically distinct from surrounding Meso- and Central American populations. Mitochondrial DNA and Y chromosome data were examined using Mayan populations available in the literature along with two newly sampled populations from Guatemala, the Ch'orti' and Poqomchi'. Poqomchi' Maya is of particular interest as their population's history has resulted in relative isolation from Europeans and non-Mayan populations. Ch'orti' history has likely allowed for a higher degree of non-Mayan and non-native admixture than found among other Mayans including the Poqomchi'. Despite nearly 500 years of colonization, the Poqomchi' and Ch'orti' Maya maintain a majority of Native American mtDNA (A, B, and C) and Y chromosome (Q) lineages. The Poqomchi' exhibit no maternal non-native gene flow, only one non-native male haplogroup, and have maintained moderate levels of genetic diversity. As expected, the Ch'orti' exhibit a higher degree of admixture for both the paternal and maternal side (26.3% and 5.3% respectively). The Ch'orti' has suffered greater genetic losses and a slower population recovery since colonization and the Guatemalan Civil War. This study shows consistently that the Mayan populations share a common history and close genetic relationship, but are not a homogenous population. The Mayan populations are closely related to other Mesoamerican populations due to shared ancestry and continued gene flow. Mesoamerican exhibits greater genetic continuity across when compared to Central America and South America. Once again, molecular markers have proven useful in elucidating the historical, geographic, and linguistic relationships among recently diverged human populations