Population History of Indigenous Peoples of The Americas - Pre-Columbian Americas

Pre-Columbian Americas

Genetic diversity and population structure in the American land mass using DNA micro-satellite markers (genotype) sampled from North, Central, and South America have been analyzed against similar data available from other indigenous populations worldwide. The Amerindian populations show a lower genetic diversity than populations from other continental regions. Observed is both a decreasing genetic diversity as geographic distance from the Bering Strait occurs and a decreasing genetic similarity to Siberian populations from Alaska (genetic entry point). Also observed is evidence of a higher level of diversity and lower level of population structure in western South America compared to eastern South America. A relative lack of differentiation between Mesoamerican and Andean populations is a scenario that implies coastal routes were easier than inland routes for migrating peoples (Paleo-Indians) to traverse. The overall pattern that is emerging suggests that the Americas were recently colonized by a small number of individuals (effective size of about 70), and then they grew by a factor of 10 over 800 – 1000 years. The data also show that there have been genetic exchanges between Asia, the Arctic and Greenland since the initial peopling of the Americas.