Thursday, January 4, 2018

Ancient Beringian DNA Sheds More Light On Native American Origins

The latest New World ancient DNA results, in broad outline, reinforce the existing paradigms, but add lots of nuggets of detail.
Despite broad agreement that the Americas were initially populated via Beringia, the land bridge that connected far northeast Asia with northwestern North America during the Pleistocene epoch, when and how the peopling of the Americas occurred remains unresolved. Analyses of human remains from Late Pleistocene Alaska are important to resolving the timing and dispersal of these populations. 
The remains of two infants were recovered at Upward Sun River (USR), and have been dated to around 11.5 thousand years ago (ka). Here, by sequencing the USR1 genome to an average coverage of approximately 17 times, we show that USR1 is most closely related to Native Americans, but falls basal to all previously sequenced contemporary and ancient Native Americans. As such, USR1 represents a distinct Ancient Beringian population. 
Using demographic modelling, we infer that the Ancient Beringian population and ancestors of other Native Americans descended from a single founding population that initially split from East Asians around 36 ± 1.5 ka, with gene flow persisting until around 25 ± 1.1 ka. Gene flow from ancient north Eurasians into all Native Americans took place 25–20 ka, with Ancient Beringians branching off around 22–18.1 ka. 
Our findings support a long-term genetic structure in ancestral Native Americans, consistent with the Beringian ‘standstill model’. 
We show that the basal northern and southern Native American branches, to which all other Native Americans belong, diverged around 17.5–14.6 ka, and that this probably occurred south of the North American ice sheets. We also show that after 11.5 ka, some of the northern Native American populations received gene flow from a Siberian population most closely related to Koryaks, but not Palaeo-Eskimos, Inuits or Kets, and that Native American gene flow into Inuits was through northern and not southern Native American groups. Our findings further suggest that the far-northern North American presence of northern Native Americans is from a back migration that replaced or absorbed the initial founding population of Ancient Beringians.


DDeden said... new article

11.5ka Luzia et. al. at Lagoa Santa Karst rockshelters, unique morphology.

Near region of the "Melanesian" genetic trace:
(from 2015)

Might Luzia et al have been from a SEAsian-Papuan group that used bark-canoes going up the Pacific coast when Beringia blocked today's cold Arctic current, via Japan's (Jomon?)Kuroshio current northeastward-eastward (south of Beringia) then southward to California & Honduras?

DDeden said...

- from my comment at West Hunter blog:

DD'eDeN January 22, 2018 at 2:13 pm

As I’ve stated elsewhere, bark-canoes (later log dugouts canoes) were invented in Papua (from Sago palm processing), logically some went north along coastal Asia following the coastal current. Beringia BLOCKED the north-south arctic cold currents (like those we currently have), so the Kuroshio-California warm currents (North Pacific swirling gyre) propelled Luzia et al’s ancestors eastwardly along Beringia’s southern coast onward to Alaska, California, Honduras to the equator where they met the northward Antarctic current and stopped. The next immigrants were Beringian landlubbers who started earlier but arrived later, who begot the AmerIndians & Na Dene etc.

My claim apparently passes genetic, architectural, linguistic, technological, migratory-least-cost-most-efficient voyage, testing as far as I can see. The original adze, the original flour pancake-flatbread, the oldest non-coracle boat, the "kelp highway" (not used by the landlubbers with their old-school wicker & yakskin kudru/ buffalo bull-boat coracles cf. Tibet & N. Dakota Mandan (between the 2 glacial massifs)). The evidence is there, my interpretation is logical. DD