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Wednesday, July 22, 2020

Nature article supports arrival of first Americans as far back as 57 Ky ago


An article published in Nature today (The timing and effect of the earliest human arrivals in North America Becerra-Valdivia, L., Higham, T. Nature (2020). https://doi.org/10.1038/s41586-020-2491-6 ) finds that:


"The data obtained show that humans were probably present before, during and immediately after the Last Glacial Maximum (about 26.5–19 thousand years ago)2,3 but that more widespread occupation began during a period of abrupt warming, Greenland Interstadial 1 (about 14.7–12.9 thousand years before 2000)4. We also identify the near-synchronous commencement of Beringian, Clovis and Western Stemmed cultural traditions, and an overlap of each with the last dates for the appearance of 18 now-extinct faunal genera. Our analysis suggests that the widespread expansion of humans through North America was a key factor in the extinction of large terrestrial mammals."


It is a first step in the right direction, and clearly states: "If transatlantic migration is set aside and an Asian origin assumed, the antiquity and distribution of the early sites suggest that the initial crossing of the 48th parallel north occurred either (i) during the later part of Marine Isotope Stage 3 (57–29 ka)36, when ice and sea level estimates37–39 indicate that land passage through Beringia was unlikely or interrupted, and an ice-free corridor between the Laurentide and Cordilleran Ice Sheets was probably present39 (with evidence of terrestrial landscapes occurring between 48 and 40 ka40) or (ii) during the LGM terminus, when the Bering land bridge was viable but the ice-free corridor was inaccessible41,42. Both possibilities sug-gest the earliest arrivals to North America had some degree of littoral adaptation."


The Clovis First theory has bean dealt a great blow! The authors write: "the previously accepted model (termed ‘Clovis-first’)—suggesting that the first inhabitants of the Americas were linked with the Clovis tradition, a complex marked by distinctive fluted lithic points1—has been effectively refuted".


It mentions several Pre-Clovis sites: "pre-Clovis sites show the earli-est evidence for cultural occupation in stratigraphic component C of Chiquihuite Cave (Mexico) at 33,150–31,405 cal., before the Last Glacial Maximum (LGM) (from 26.5 to 20–19 ka2,3). Several sites appear to be occupied later, during or immediately after the LGM. These include Gault (26,435–17,385cal.), Meadowcroft Rockshelter (24,335–18,620cal.) and Cactus Hill (20,585–18,970cal.) (Fig.2a). In eastern Beringia, Bluefish Caves is represented by a single date obtained on a humanly modified bone sample (24,035–23,310cal.) dating squarely to the LGM..


It is encouraging, and should undo the dark work of William Henry Holmes of the Smithsonian Institution, Thomas Chamberlin of the United States Geological Survey and Ales Hrdlicka (of the Smithsonian) who refused to accept that humans had reached America before the end of the last Ice Age. They imposed their ideas and only accepted an earlier (but not too early) date when the Folsom points were found in 1927 followed by the Clovis ones in the 1930s. They were irrefutable confirmation of ancient humans in the Americas during the Pleistocene.


But pushing the dates beyond 12-13,000 years has proven difficult. Let's hope this article marks a new trend in the field.


Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2020 by Austin Whittall © 

2 comments:

  1. Very interesting!…immigration at MIS3, even handled as a tentative possibility , is at least another step of advance.
    I too believe that articles like this could contribute to a somewhat more realistic approach to the subject of what could have happened in America… However, I think that further understanding on other additional aspects involved in, that would be helpful to shed more light on this subject, is still missing;
    a) The particularly low archaeological visibility of ancient (pre LGM, and well beyond) cultural/anthropological remains in America:
    …an aspect that could be due to many reasons, that would indeed be worth to be analyzed;…a possible very low demography context, relative geographical isolation, possible human settlements on lands posteriorly denudated by climatic events (*), or on currently submerged areas, among others… although none of them has received enough interest by researchers.
    b) The strikingly low visibility (if such a term could apply for this) manifested up to now by the mainstream archaeologists (yet some very respectable professionals may not be exempt from this) every time such “weird” remains appeared in America:
    …which is a subject you have treated in several posts.
    This “visibility factor”, either due to any or to both reasons (being (b), the most conditioning one), is responsible for the labeling of America as “the last continent to be peopled”, where “only a behaviourally modern H. sapiens could have first immigrated”… statements that today, in my personal opinion, constitute a highly debatable matter.
    Best regards
    Marcelo

    (*) At this particular respect, it would not be reckless to suspect that many (if not almost all) possible ancient settlements that could have been emplaced in North America above latitude 40/45 degrees N, were destroyed by the action of the glaciers, either during the peaks of the Wisconsin glaciation (at MIS2 and MIS4), or during the previous one (the Illinoian glaciation, ca 180-140 Ka, which is believed to have been even more rigorous and more geographically extended than the former), reason why this region is not precisely the most suitable one in order to search for the earliest signs of human activity in the continent… An interesting counterexample of this may be Cerutti Mastodon site (130 Ka), located at 32/33 degrees N, well below the maximum extent of these glaciations.

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  2. That could explain the diversity of languages in Americas.

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