An international team of researchers has sequenced and analyzed the genomes of 93 ancient Caribbean islanders and found evidence of at least three separate population dispersals into the region: two early dispersals into the Western Caribbean, one of which seems connected to earlier population dispersals in North America; and a third, more recent wave from South America.
Illustration of one of the early settlers in the Caribbean. Image credit: Tom Björklund.
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 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 from the Max Planck Institute for the Science of Human History and colleagues analyzed genome-wide data from 93 ancient Caribbean islanders who lived between 400 and 3,200 years ago using bone fragments excavated from 16 different archaeological sites across the Caribbean.
The 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 new data give us a fascinating glimpse of the early migration history of the Caribbean,” said senior co-author Dr. Hannes Schroeder, a researcher in the Globe Institute at the University of Copenhagen.
“We find evidence that the islands were settled and resettled several times from different parts of the American mainland.”
“Big bodies of water are traditionally considered barriers for humans and ancient fisher-hunter-gatherer communities are usually not perceived as great seafarers,” Nägele said.
“Our results continue to challenge that view, as they suggest that there was repeated interaction between the islands and the mainland.”
“The new data support our previous observations that the early settlers of the Caribbean were biologically and culturally diverse, adding resolution to this ancient period of our history,” said co-author Dr. Yadira Chinique de Armas, a researcher at the University of Winnipeg.
The team’s 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 scientists found almost no evidence of admixture, raising intriguing new questions about their interactions.
“Although different groups were present in the Caribbean at the same time, we found surprisingly little evidence of admixture between them,” said co-author Dr. Cosimo Posth, a researcher at the Max Planck Institute for the Science of Human History.
“The results of this study provide yet another layer of data that highlights the diverse and complex nature of pre-Columbian Caribbean societies and their connections to the American mainland prior to the colonial invasion,” said co-author Professor Corinne Hofman, a scientist at Leiden University.
The findings were published in the journal Science.
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Kathrin Nägele et al. Genomic insights into the early peopling of the Caribbean. Science, published online June 4, 2020; doi: 10.1126/science.aba8697
