Genetic structure and biodemography of the Rama amerindians from the southern caribbean coast of Nicaragua

Abstract

This dissertation examines the evolutionary impact of recent historical events on the population structure of the Rama Amerindians who inhabit the southern Caribbean coast of Nicaragua, by analyzing the mitochondrial DNA (mtDNA) polymorphic variants and their biological relationship with, and ancestral divergence from other neighboring groups. Genetic profiles of 265 individuals from seven Rama communities revealed that the majority of individuals belong to haplogroup B2 (71%) or A2 (28%), with the remaining 1% of variation comprised by the maternal lineages C1 and L3. Based on multivariate analyses combined with median-joining networks, AMOVA, tests of selective neutrality and diversity, phylogeography, and surname isonymy analyses, it is proposed that the geographic distribution of the haplogroups among the Rama communities reflects the history of migration of this population after the European incursion into the Caribbean region of Southern Central America following the 16th century. Ethnographic and ethnohistorical accounts of sub-population fissions and subsequent forced migrations are congruent with these results, leading to the conclusion that the disruption of the Rama’s traditional way of life led to changes in mortality patterns, reproductive dynamics and epidemiology, which ultimately impacted the genetic variation of this population.