DNA indicates humans in N. America 14,300 years ago(boston.com)
boston.com
DNA indicates humans in N. America 14,300 years ago
http://www.boston.com/news/science/articles/2008/09/21/dna_indicates_humans_in_n_america_14300_years_ago/
http://www.boston.com/news/science/articles/2008/09/21/dna_indicates_humans_in_n_america_14300_years_ago/
How exactly do they do that?