GAINESVILLE, FLORIDA—According to a statement released by the Florida Museum of Natural History, researchers led by David Reich of Harvard Medical School and William Keegan of the Florida Museum of Natural History traced two waves of migration in the Caribbean through the analysis of the genomes of people who lived in the Caribbean and Venezuela between 400 and 3,100 years ago. Reich said that the first wave included individuals who were more closely related to groups living in Central and South America than in North America. They arrived in Cuba some 6,000 years ago. Then between 2,500 and 3,000 years ago, farmers and potters related to Arawak speakers from northeastern South America landed in Puerto Rico and eventually moved to other islands to the west. The two groups rarely mixed, and very few modern individuals are descended from the first-wave migrants, Reich explained. The results of the study therefore indicate that changes observed in Caribbean pottery styles over time were not due to the arrival of new populations. The scientists also developed a technique to estimate population size that reduced the estimated number of people living in the Caribbean at the time of European contact from a million or more to just tens of thousands. For more on the peopling of the Caribbean, go to "Around the World: Caribbean."