The islands of the Caribbean were settled and resettled by at least three successive waves of colonists from the American mainland, according to a new study, which presents new findings from an examination of ancient DNA from 93 early Caribbean islanders. The results not only inform upon the initial settlement of the Caribbean but also reveal a complex population history and ties to broader, inter-continental human expansions in both North and South America. The Caribbean Islands were one of the last regions in the Americas to be settled by humans. The earliest archeological evidence suggests that the Caribbean's first residents arrived roughly 8,000 years ago, and by 5,000 years ago, were widely dispersed. However, how, when and from where the region's first colonists came to the inhabit the islands of the Antilles isn't well understood. Much of the Caribbean's settlement history has heavily relied on interpretations from archaeological findings, such as the stylistic comparison of artifact collections between Caribbean sites and those from the surrounding mainland. While these approaches have illuminated broad-scale population movements, many of the more nuanced aspects of Caribbean population history remain unknown. To fill these gaps, Kathrin Nägele and colleagues analyzed genome-wide data from 93 ancient Caribbean islanders who lived between 400 and 3,200 years ago. Nägele et al.'s analysis provided new genetic evidence of at least three separate colonization events, including two early dispersals into the Western Caribbean - one of which was previously unknown and may have been connected to radiation events in North America that predate the diversification of Central and South American populations. Afterward, a later expansion of groups from South America arrived and brought new technologies, including pottery, supporting previous archaeological interpretations. The results also revealed distinct genetic differences between the ancestors of the region's earliest settlers and the newcomers from South America. Despite coexisting for centuries, the authors found almost no evidence of admixture, raising intriguing new questions about their interactions.
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Journal
Science