Cienciaes.com: The first settlers of the Caribbean. We spoke with Miren Iraeta Orbegozo

2020-06-14 19:24:43

The moment in which the first human migration in America took place is still a cause of debate among scientists. The oldest indications indicate that the settlers arrived during the Last Glacial Maximum, more than 24,000 years ago. These first humans came from Siberian lands and arrived in North America taking advantage of the fact that the sea level had dropped to such an extent that Asia and North America had been joined by a narrow strip of land. Those first settlers inhabited the northern regions for millennia and began a long journey southward until they populated the entire American continent.

Among all the events that have occurred since the arrival of human beings in America, the population movements that inhabited the Caribbean islands deserve a special chapter. The region is made up of more than 700 islands, islets and cays that delimit the sea that bathes the coasts from Florida to Venezuela. This region was one of the last to be colonized by humans, and they did so in at least three successive waves of settlers from the mainland. Archaeological evidence suggests that the first settlers arrived on the islands 8,000 years ago, although their provenance is unknown. The oldest sites whose dating is known for sure are 5,000 years old and are widely scattered, in Barbados, Cuba, Curaçao, Saint Martin, Hispaniola and Puerto Rico. This dispersal suggests that the first settlers made long and fast jumps across the Caribbean without a gradual advance being able to be observed that would allow us to know the starting point.

The initial migration, called “archaic” populated most of the islands and was followed, much later, by another that began around 2,800 years ago. These new settlers mark the beginning of what is known as the “Caribbean Ceramic Age” characterized by highly distinctive ceramic remains, permanent settlements, and agricultural practices. Both the archaeological remains studied and the genetic studies of the bones of those settlers indicate that they came from South America, although the route followed is not known with certainty. Two hypotheses divide the scientific community, some defend that they came from what is now the Venezuelan coast and from there they were jumping from island to island through the Lesser Antilles to the North until they reached Puerto Rico, Hispaniola and Cuba; others maintain that the first point of entry was Puerto Rico and from there they dispersed to the rest of the islands.

Now, a study published in Science, signed by Kathrin Nägele, Cosimo Posth and Miren Iraeta Orbegozoour guest on Talking to Scientists, uses the analysis of the ADN of 93 individuals that inhabited different Caribbean islands between 3,200 and 400 years ago to obtain additional information on population movements. The remains come from two different archaeological contexts, found on various islands: the so-called “Archaic”, to which 52 individuals between 3,700 and 700 years old belong, and remains of 41 individuals from 1,500 to 400 years ago. called “Ceramics”. Comparison of their genomes with each other and with those of twelve other living Native American populations reveals interesting facts about their provenance and the relationship between them.

The data from ADN they show very clear differences between the Archaic and the Ceramics and also indicate that the mixture between them, despite having lived together for many years, is very scarce. The comparison between the genetics of these populations and the current natives reveals that the individuals of the Ceramic Age have a close relationship with the natives of South America. In contrast, genomic analyzes of “archaic” individuals show no relationship to current variation in Native Americans.
A third expansion, which also originated in South America, took place later and has left good archaeological information.

Miren Iraeta Orbegozo he discusses this research and his experience as a master’s student at The Globe Institute, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. I invite you to listen to it.

Reference:
K. Nägele et al.,“Genomic insights into the early peopling of the Caribbean”: Science 10.1126/science.aba8697 (2020).