Divergent genetic strata in five Bahamian islands

Abstract

Based on historical records, the genetic landscape of the Bahamian archipelago is presumed to be complex and to exhibit island-specific characteristics, yet the genetic composition of the island chain, which could corroborate or refute these past accounts, remains poorly defined. As such, the current investigation was undertaken to genetically characterize 5 Bahamian populations representing the Northwest (Grand Bahama and Abaco) and Central (Eleuthera, Exuma and Long Island) Bahamas across the 15 autosomal Identifiler loci routinely employed in forensic analyses. Altogether, our findings suggest that Bahamians are a genetically heterogeneous group, with each island sampled receiving differential contributions from African, European, East Asian and Native American sources. Even though the strongest genetic signal in all 5 collections emanates from continental Africa, inter-island differentiation is noted in both the Structure and admixture analyses. The presence of alleles not in common among the 5 insular populations also signals genetic heterogeneity among the islands of the archipelago. This is especially the case when considering the Long Island population, which exhibits statistically significant genetic differences in relation to the other Bahamian collections and the New World groups of African descent (Afro-American and Afro-Caribbean) in the G-test pair-wise comparisons, even after application of the Bonferroni adjustment.