completely different populations of people, changed only by modern methods of transportation to include different races.
according to population science, there were significant changes in the DNA of those peoples who in 10,00-years migrated from africa, through europe and north siberia over the bering strait into north america. there have been significant changes in continental drift and in the water levels, since those times.
recent studies show that the north american populations migrated in to mexico, central and south america. the native peoples of canada have a distinct DNA, separate from the lower american, and the mexican DNA, those of central, and the south american peoples. these changes were observed almost immediately after the first out-of-africa migrations through forensic-anthropology.