Where do Native Americans come from?

Using mitochondrial DNA, Ugo Perego has shown that the peopling of the Americas thousands of years ago was far more complex a process than previously thought. Until now, only six founding female lineages had been calculated as being ancestral to modern Native Americans, suggesting a small-scale migration 15-18,000 years ago. But Perego's team has identified more founding lineages, bringing the total up to 15, indicating that the founding population of the Americas was much more diverse. than previously thought.