Inferring the Early History of Northern South America through Mitochondrial DNA Analysis

Abstract

Prior to the mass colonization of the Americas, early peopling consisted of Indigenous Americans who, over the course of tens of thousands of years, came to occupy the continents that would later be settled by the ambitious European powers of the time. Through the use of mitochondrial DNA (mtDNA) sequencing throughout numerous samples, as well as temporal analysis of genetic mutations within samples of the same haplogroup, the migrations of different early indigenous populations can be tracked across the geography of the continent, and the ethnographic composition of different regions can be reconstructed with respect to the time period. Given that haplogroups belonging to maternal Amerindian descent are identified by haplogroups A, B, C, and D, and that genetic variations in haplogroups can be tracked over time, it is possible to approximate a model of the early genetic composition of Colombia and other regions of northern South America through the use of samples from model haplogroups like A2al, B2d14, C1d2, and D4h3a. For this study, 94 samples across these haplogroups have been surveyed, and individual phylogenetic trees have been constructed, which each infer a genetic timeline for the mutations found under each haplogroup. With the construction of a phylogenetic tree for each of the four haplogroups, a larger, cumulative phylogenetic tree was also constructed, which in combination with the known presences of haplogroups across the geography of Colombia, can provide insight into the early migration and settling patterns of these early pre-columbian Indigenous Americans.