遺伝学：カリブ海沿岸地域の人類集団史には2つの大きな移動の波があった

Humans settled the Caribbean in two major waves of migration prior to the arrival of Europeans, according to research published in this week’s Nature. The study provides a detailed analysis of ancient Caribbean population history, and reveals that descendants of these Indigenous inhabitants are still living in the Caribbean today.

Relatively little is known about the population history of the Caribbean between its first settlement and the arrival of Europeans at around 500 years ago. In this study, David Reich and colleagues analysed the genomes of 174 ancient individuals from across the Caribbean who lived between about 3,000 and 400 years ago, and used these and other publicly available data to study ancient population sizes and migrations. By around 3,000 years ago, the region had been settled by people from Central or northern South America, who had brought their stone tool technology with them. This population was largely genetically replaced by a second wave of migrants, who travelled from northeast South America through the Lesser Antilles and into the Greater Antilles, arriving at least 1,700 years ago. These later people brought their own culture, characterized by the use of ceramics and an agricultural economy.

Earlier estimates suggested that hundreds of thousands or millions of people lived in the Caribbean in the period leading up to European colonization, but this study suggests that overall population sizes were much smaller, in the tens of thousands. Their legacy persists today, as people living in some parts of the Caribbean carry genetic sequences that come from pre-contact Indigenous populations, as well as DNA inherited from immigrant Europeans and the Africans who were brought to this region during the trans-Atlantic slave trade.