At www.eurekalert.org/pub_releases/2015-07/uoc–gap072115.php … a genome study at the University of California-Berkeley has concluded Native Americans ae descended from a single migration from Siberia which they now date 23,000 years ago (purely on DNA evidence and assumed rates of divergence). From the perspective of neo-catastrophism this date is highly significant – at the height of the last Glacial Maximum. Whereas uniformitarians visualise ice sheets covering the whole of the northern hemisphere (or at least, extremely cold tundra) neo-catastrophists are prepared to think about the possibility that the Late Glacial Maximum represents a shift in the position of the North Pole (as explained by physicist Peter Warlow at the last SIS Cambridge Conference) between roughly 30,000 and 16,000 years ago. One clue is that mammoths lived in Siberia – and as elephants they consume vast quantities of grass, herbs, and shrubs – which obviously would not have been available if there was an ice sheet in the far north or they only had a few sedges and tundra plants to survive on. Elephants also consume large amounts of water – drinking water not frozen water. Mammoths were bigger than elephants – but closely related. The eivdence on the ground is that the ice sheet was primarily situated in NW Europe and NE N America – which means large tracts of Siberia and Alaska were temperate (possibly with a steppe like environment, perfect for elephants and other large herbivores). In other words, people in Siberia merely had to cross the Arctic Ocean in their boats to reach the Americas – and no doubt this is what happened.
The article, in the journal Science (July 24th, 2015) and it seems two camps have developed on the origins of Native American. The main one (as in this article in Science) is that they came almost wholly from Siberia – which appears to be an extension of the Clovis First idea, the dominating theory of the 20th century and one that would have no truck with opposing views. The other camp is marked thinks Native Americans had a more diverse origin and their views are also published this week in a paper in Nature which says that genetic studies link indigenous peoples in the Amazon with Australasia – go to http://archaeologynewsnetwork.blogspot.co.uk/2015/07/genetic-studies-lin…
Intriguingly, in the first link (Science paper) they say there is a small admixture of genes of East Asians and Australo-Melanesians – but these are assumed by the authors to be late arrivals (at some point in the Holocene and long after the Ice Age). In the end archaeology will be one of the deciders – if humans can be found to have been living in the Americas prior to 23,000 years ago.