March 28, 2011

First Humans In The Americas 15,500BP - New Evidence

Some of the artifacts from the 15,500-year-old horizon - Michael R. Waters


Above map and following excerpt from The Oldest Americans - An Introduction by George Weber:

The (above) routes into America were available to the intrepid and hardy Pleistocene and early Holocene traveler. The routes were undoubtedly used (although we cannot be sure which ones and by whom) and that from as early as 30,000 years ago. The people who set up camp at Monte Verde in Chile, for example, had to enter America by one of the routes or a combination of them.

(a) Bering Straight route (blue)
The Bering Strait before 10,000 years ago was an icy and stormy waterway and something for only the most fearless boat crew to attempt. Every so often, as the climate became colder and sea levels fell, the Strait would turn into dry land and could be crossed on foot by people with a well-established tradition of arctic survival.

(a+b) a combination of Bering and Pacific Coastal routes (blue and black)
The Inuit (Eskimos) and Aleut are two people speaking related languages who appear to have been a third wave (after the PalaeoAmerinds and the Amerinds) of migrants into the Americas over or near the Bering Strait after the Inuit and Aleuts. Genetic evidence suggests that the two groups split up in Siberia around 10,000 years ago before entering the Americas. It is an intriguing (but unproven) thought that the Aleuts (who settled in the Aleutian islands around 6,000 years ago) represent route b of the graph above, while the Inuit (who crossed into Alaska a little later and came on route a.

(b) Pacific coastal route (black)
Contrary to the experts who hold that the ancient migrants into America would have needed to walk, a boat trip along the ice shelf and coast is in fact a far more likely route for Pleistocene migrants. For people with simple canoes on this route, even at the height of the ice age, the sea would have been open off the glaciers. The migrants could follow the fish and so would not even have needed to carry much provisions. Even fresh water should not have been an insuperable obstacle in the presence of so much frozen water. People like the Fuegian Yamana and Kwaseqar (see Fuegians and Patagonians) could even have done such Pleistocene traveling naked! In one of the world's stormiest and unpleasantest climates (Tierra del Fuego) the aborigines until very recently have gone on lengthy boat trips and dived for seafood - without a stitch on. In fact, during the Pleistocene, the inland route a, if open, could well have have been second choice. Sea currents and wind directions were not of major importance to early migrants on the coastal route since they could paddle along the coast and seek shelter on the many islands or even on icebergs. Much as the Yamana and Kwaseqar people have done until very recently.

(c) Pacific crossing route (yellow)
This does not seem a very likely route in view of the rather advanced long-distance sailing and navigational skills that would have been needed at an early date. It could have been a rare "accidental route", though. The survival of such travelers until they are washed ashore in South America is, however, is most unlikely. . The only specks of land in the immensity of the southern Pacific Ocean would have been tiny Pitcairn and Easter islands and the Juan Fernandez islands. None of them has yielded archaeological evidence of ancient visitors. Even famous Easter island was not reached by Melanesians until around 400 AD (earliest estimates). It is also noticeable that the South Sea islands were not settled until around 4,000 years ago despite the fact that insular Asia and Papua-New Guinea had been populated by modern humans for 40-50,000 years. On present evidence, these early modern humans in Asia and Australia appear to have ignored the open Pacific for tens of thousands of years. Although the Pacific crossing seems somewhat unlikely, it cannot be definitively excluded as a source of migrants to early America, because:

(1) we know almost nothing about wind systems and monsoon pattern in the South Pacific during the Pleistocene ice age. It is possible that winds were more favourable to sailors heading east (deliberately or accidentally) then,

(2) absence of evidence is not evidence of absence - if the travellers heading east were few and far between, they would have left so little evidence on the islands they may have landed on or on the American coast that they simply have not been found yet - and could be found only by a major stroke of luck. Australian aborigines are not known for their long-distance boating skills, but boats from an as yet undiscovered Australian tribe of skilled and very lucky sailors may have made it to South America, if only accidentally. Enigmatic prehistoric cave paintings in Patagonia (see Fuegian and Patagonian archaeology) are eerily reminiscent of Australian aboriginal cave paintings). Coincidence? We do not know.

The prevailing winds north of the permanent high pressure area off the South American west coast would have been against vessels sailing east towards the Americas for the past 10,000 years.Further south, wind direction would have been more favourable but would have led any vessels into one of the world's most notoriously stormy waters, but conditions may have been more favourable during the Pleistocene period before 10,000 years ago. Again - we just do not know.

(d) Atlantic crossing route (orange)
During the Pleistocene this route must have led along the fronts of monstrous glaciers and along an extremely stormy polar front (the border between cold polar and warm tropical air) that reached much further south into the Atlantic than the comparably puny Greenland glaciers and polar fronts of today. Any travel west along this front more than 10,000 years ago would have most likely been limited to unfortunate stragglers with little chance of survival. Both normal wind and sea surface currents were against travellers attempting to sail west. There are nevertheless some intriguing similarities in stone tool technology between prehistoric Europe and America and there is the enigmatic presence of European haplogroup X among Amerindian populations 1,300 years ago. Some lucky early European migrants do seem to have made it to the Americas it against all the odds (see also caption to map above).

It was much more recently, around 800 AD that the Vikings did unquestionably reach America by using their very advanced sailing technology. Archaeological finds at L'Anse aux Meadows in Newfoundland revealed a short-lived Viking trading station dated to around the year 1000 AD. The "official discoverer" of America, Leif Erikson, knew that there was land to the west and there can be no question that there had been earlier explorers and traders who returned to tell their tales. There cannot have been many such and their exploits are unlikely to go back further than around 500 AD. Of earlier explorers there is no evidence, although it is not impossible that there were Celtic, Greek or Roman vessels that might have managed to reach America.

The prevailing winds across the northern Atlantic would have been against vessels sailing west. Further south, wind direction would have been more favourable.  The prevailing sea surface current would not have been favourable.

(e) African equatorial route (brown)
The route from Africa across the Atlantic is a possibility that has not received the consideration it would deserve. Evidence of prehistoric African migration to the Americas is lacking but this may be because nobody has been looking. The prevailing winds from both north and south of the equator would have been basically favourable for vessels sailing west, but the extended doldrums in critical areas north of the equator and the uncertain surface currents around the Sargasso Sea might have been a serious discouragement to would-be sailors. Perhaps the genetic evidence for early migration is there but has not been found or recognized yet. "Luzia" (the most famous of the Lagoa Santa "Lapa Vermelha people") does seem to have some African (or perhaps Australian? in any case, quite un-Amerindian) features. No genetic work on this intriguing prehistoric population has been published as yet. For the moment it remains remarkable that there is no solid evidence for an early African migration across the Atlantic.

More on the Origins of Native Americans:

Earliest Americans Arrived in Waves, DNA Study Finds, By Nicholas Wade, The New York Times, Science, July 11, 2012
1491: New Revelations of the Americas Before Columbus
Footprints Debate to Run and Run
Tribe Challenges American Origins
Tracing Humanity's Path
The Oldest Americans - An Introduction by George Weber
The Oldest Americans - Archaeological Sites by George Weber
The Pre-Clovis and Clovis World

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