David Reich, Harvard Medical School professor of genetics, is the author of a study that show a link between Amazon people and Australasia. The study, in Nature (July 23rd, 2015) says that according to Reich the findings were surprising as there is a strong working model in archaeology and genetics that Native Americans were derived from a single pulse of expansion south of the ice sheets. However, this is wrong he says as we now have evidence that there were migrants from other than Siberia. This idea of a link with Australasia is not new as prior to genetics it was thought, due to cranial studies, there was such a connection. This was dismissed once genetics appeared to show all Native Americans are descended from immigrants from Siberia. It also proves that genetic studies are not final if they do not include a wide sample of different tribal groups. In this case, it was tribes from the Amazonian rainforest that have preserved their roots in Australasia, having lived in isolation from other groups of Americans.
Reich says that not only was there more than one influx between Siberia and Canada but we also have the Brazilian genes to account for – but what about the Patagonian tribes recorded by early settlers. Have they been genetically studied. The two Amazon tribes are connected to people from Australia (Aborigines) and New Guinea (and more widely, from the Andaman Islands in between India and SE Asia). See http://archaeologynewsnetwork.blogspot.co.uk/2015/07/genetic-studies-lin… and www.smithsonianmag.com/science-nature/dna-search-first-americans-link-am…