First, the distant past. The islands were initially inhabited 6,000 or so years ago by hunter-gatherers genetically identical to those in Central America. Once settled they remained largely cut off from the mainland, developing "a very distinctive deep lineage." The population was low. Honestly it sounds somewhat like paradise, with a small population easily feeding itself from fishing, gathering turtle eggs, and so on. But something had to be keeping the population low, perhaps disease.reviving their native past, and these findings will no doubt encourage that movement.
Ancient Caribbean people avoided close kin unions despite limited mate pools that reflect small effective population sizes, which we estimate to be a minimum of 500–1,500 and a maximum of 1,530–8,150 individuals on the combined islands of Puerto Rico and Hispaniola in the dozens of generations before the individuals who we analysed lived. Census sizes are unlikely to be more than tenfold larger than effective population sizes, so previous pan-Caribbean estimates of hundreds of thousands of people are too large.