Paternal lineages signal distinct genetic contributions from British Loyalists and continental Africans among different Bahamian islands

Abstract

Over the past 500 years, the Bahamas has been influenced by a wide array of settlers, some of whom have left marked genetic imprints throughout the archipelago. To assess the extent of each group's genetic contributions, high-resolution Y-chromosome analyses were performed, for the first time, to delineate the patriarchal ancestry of six islands in the Northwest (Abaco and Grand Bahama) and Central (Eleuthera, Exuma, Long Island, and New Providence) Bahamas and their genetic relationships with previously published reference populations. Our results reveal genetic signals emanating primarily from African and European sources, with the predominantly sub-Saharan African and Western European haplogroups E1b1a-M2 and R1b1b1-M269, respectively, accounting for greater than 75% of all Bahamian patrilineages. Surprisingly, we observe notable discrepancies among the six Bahamian populations in their distribution of these lineages, with E1b1a-M2 predominating Y-chromosomes in the collections from Abaco, Exuma, Eleuthera, Grand Bahama, and New Providence, whereas R1b1b1-M269 is found at elevated levels in the Long Island population. Substantial Y-STR haplotype variation within sub-haplogroups E1b1a7a-U174 and E1b1ba8-U175 (greater than any continental African collection) is also noted, possibly indicating genetic influences from a variety of West and Central African groups. Furthermore, differential European genetic contributions in each island (with the exception of Exuma) reflect settlement patterns of the British Loyalists subsequent to the American Revolution.

The peopling of the African continent and the diaspora into the new world

“…In addition, genome-wide data have suggested that patterns of genetic ancestry in Cuba, Puerto Rico and Hispaniola (the Greater Antilles) were consistent with a model of two migration events from different regions of western Africa, implying that Afro-Caribbean populations have mixed African ancestry [102•]. These results are also congruent with a Y-chromosome study that found diverse haplotypes in Afro-Caribbeans from the Bahamas that were inferred to originate from different ethnic groups within West Central Africa [103]. Furthermore, isotope data from skeletal remains of enslaved Africans in Barbados suggested that first generation captives had different dietary histories likely due to differences in their geographic origins in Africa [104].…”

An anthropological genetic perspective on creolization in the anglophone caribbean

“…These studies indicate that among African Caribbean populations found in Jamaica, Haiti, the Bahamas, St. Thomas, Barbados, and Trinidad and Tobago, there is about 65-95% African ancestry, 4-27% European ancestry, and 0-6% Native American ancestry (Parra et al, 1998;Molokhia et al, 2003;Miljkovic-Gacic et al, 2005;Benn-Torres et al, 2008;Simms et al, 2008Simms et al, , 2010Simms et al, , 2011Murray, 2010;Wilson et al, 2012). Generally, triparental admixture estimates are quite similar between these Anglophone islands.…”

“…Nonetheless, the admixture estimates observed in the sampled populations are comparable with the estimates of previous research that used autosomal markers. These studies indicate that among African Caribbean populations found in Jamaica, Haiti, the Bahamas, St. Thomas, Barbados, and Trinidad and Tobago, there is about 65-95% African ancestry, 4-27% European ancestry, and 0-6% Native American ancestry (Parra et al, 1998;Molokhia et al, 2003;Miljkovic-Gacic et al, 2005;Benn-Torres et al, 2008;Simms et al, 2008Simms et al, , 2010Simms et al, , 2011Murray, 2010;Wilson et al, 2012). Ancestry studies based on uniparentally inherited markers also show that for African Caribbean people in general, African woman, African men and European men made the most substantial genetic contributions to contemporary populations (Benn Torres et al, 2007;Deason et al, 2011Deason et al, , 2012Gaieski et al, 2011;Simms et al, 2012a,b;Benn Torres et al, 2012).…”

Molecular Dissection of the Basal Clades in the Human Y Chromosome Phylogenetic Tree

“…It is worth noting that three additional A1b chromosomes have been recently found in Caribbean populations, which exhibit substantial Y-STR haplotype sharing with Y chromosomes from Gabon [35], [36]. Taken together, all these data reinforce the hypothesis of an origin in the north-western quadrant of the African continent for the A1b haplogroup [16], and, together with recent findings of ancient Y-lineages in central-western Africa [19], provide new evidence regarding the geographical origin of human MSY diversity.…”