Investigating MtDNA Lineages for 31 Ancient Caribbean Ancestors from Puerto Rico, Barbados and Carriacou
Introduction: The pathways by which the Caribbean was settled have yet to be fully understood, but genetic research may help to illuminate the region’s complex history. However, the impact of colonialism and the Trans-Atlantic slave trade limits what can be
deduced from modern DNA alone. Here we use ancient DNA (aDNA) to investigate pre-contact ancestries as part of a broader project reconstructing the genetic diversity of ancient Caribbean populations. We focus on single nucleotide polymorphisms (SNPs) in the highly variable regions of mitochondrial DNA (mtDNA) alongside contextual information from literature sources to illuminate geographical ties and migratory histories.
Methods : We analyzed newly sequenced low coverage shotgun data for 62 Ancestors from Barbados, Carriacou and Puerto Rico (PR). 31 individuals (PR n=5, Carriacou n=14, Barbados n=12) had sufficient coverage for preliminary haplogroup inference. We analyzed these sequences alongside mtDNA haplogroup assignments and data from previous studies to identify shared lineages and derived SNPs.
Results: Seven individuals were assigned to mtDNA haplogroup A2, five individuals were assigned to B2, eight individuals were assigned to C1, four individuals were assigned to D1 and seven individuals were assigned to D4. These assignments are characteristic of the first expansion into the Americas and are reported throughout the Caribbean and continental Americas.
Conclusion: Shared haplogroups across these islands help to illuminate the complex history of the Caribbean, with ties through time and space suggesting precolonial