Forced Migration and Population Expansion: The Genetic Story of the Garifuna

Abstract

The Garifuna are an admixed population that are found on St. Vincent Island in the Lesser Antilles and in over 60 villages in Central American, stretching along the coasts of Belize to Nicaragua. They were born out of admixture between the last native inhabitants of the Caribbean and escaped slaves. When Britain took control of the island in 1797, most Garifuna were forced to the island of Roátan, over 1,700 miles from their homeland. Roughly 2000 Garifuna survived war, disease, and deportation to Roátan. Today, over 300,000 Garifuna are estimated to live in Central America and large cities in the United States. Previous studies of Garifuna in St. Vincent and along the Central American coast have shown that the Garifuna are an admixed people with African, Native American, and some European genes. This work furthered these studies using uniparental markers, mitochondrial DNA and the non-recombining Y, to focus on some of the earliest Garifuna villages in Punta Gorda, Roátan and the Honduran Coast to better determine their origins and understand how a population adapts and expands in a new environment. Compared to the island of St. Vincent, coastal communities in Honduras have a reduced diversity and fewer native mtDNA or Y-chromosome haplotypes. Most mtDNA and Y lineages that are of African origin resemble West African regions from the earliest ports in the Atlantic slave trade, from Senegambia to the Bight of Biafra; however, there is evidence of origins from other parts of Africa. The mtDNA diversity in Garifuna Amerind Y haplotypes on St. Vincent appear most closely related to groups in South America, where the first peoples of the Lesser Antilles where thought to have originated. However, Y haplotypes from Honduras show that admixture with neighboring populations gave rise to half of the Y lineages belonging to native haplogroup Q. The lower diversity in the Garifuna is a sign of a population that has gone through multiple bottlenecks. However, admixture with nearby groups, and an increase in migration in the Garifuna has worked toward increasing the diversity within Garifuna communities.