What is the earliest evidence of the peopling of North and South America?
The timing of the first appearance of humans in the Americas is debated. For many years, experts believed that people first migrated into North America 12,000 years ago. New finds have led some researchers to push for a first appearance date of 30,000 to even 40,000 years ago. The migration route is also disputed. It was once thought that the earliest migration took place across a land bridge connecting Siberia and Alaska, but now researchers are open to the possibility of new routes, including those along the northern sea coast from Europe. Using new dating and genetic techniques, Paleo-American researchers are looking for new answers to age-old questions.
For more information check out: http://www.pbs.org/wgbh/nova/first/claimbonn.html