LAWRENCE, KANSAS—According to a Live Science report, a new genetic study conducted by an international team of researchers suggests there were about 250 people in the first group to enter the New World from Siberia some 15,000 years ago. Nelson Fagundes of Federal University of Rio Grande do Sul in Brazil, Michael Crawford of the University of Kansas, and their colleagues analyzed DNA samples obtained from ten Native American individuals living in Central and South America, ten people from different Siberian groups, and 15 people from China. Computer simulation models helped the scientists work backward from the genetic variation and divergence seen in the populations today to figure out the original size of the so-called founding group. “Large populations have very efficient selection,” Fagundes explained, “while in small populations, mildly deleterious alleles can spread, which may increase genetic susceptibility to some diseases.” The estimate for the founding population in this case is so small that there would have been little genetic variation associated with the first wave of migration. Fagundes added that new genetic mutations, and the addition of later waves of migrants, eventually increased genetic diversity among Native American populations. To read in-depth about the first people to arrive in the Americas, go to “America, in the Beginning.”
