First humans arrived in North America 10,000 years earlier than believed

Discussion in 'General Science & Technology' started by paddoboy, Jan 19, 2017.

  1. paddoboy Valued Senior Member

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    First humans arrived in North America 10,000 years earlier than believed
    January 16, 2017

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    This horse mandible from Cave 2 shows a number of cut marks on the lingual surface. They show the animal’s tongue was cut out with a stone tool. Credit: University of Montreal
    The timing of the first entry of humans into North America across the Bering Strait has now been set back 10,000 years.

    This has been demonstrated beyond a shadow of a doubt by Ariane Burke, a professor in Université de Montréal's Department of Anthropology, and her doctoral student Lauriane Bourgeon, with the contribution of Dr. Thomas Higham, Deputy Director of Oxford University's Radiocarbon Accelerator Unit.

    Read more at: https://phys.org/news/2017-01-humans-north-america-years-earlier.html#jCp
     
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  3. paddoboy Valued Senior Member

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    http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0169486


    Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada:


    Abstract
    The timing of the first entry of humans into North America is still hotly debated within the scientific community. Excavations conducted at Bluefish Caves (Yukon Territory) from 1977 to 1987 yielded a series of radiocarbon dates that led archaeologists to propose that the initial dispersal of human groups into Eastern Beringia (Alaska and the Yukon Territory) occurred during the Last Glacial Maximum (LGM). This hypothesis proved highly controversial in the absence of other sites of similar age and concerns about the stratigraphy and anthropogenic signature of the bone assemblages that yielded the dates. The weight of the available archaeological evidence suggests that the first peopling of North America occurred ca. 14,000 cal BP (calibrated years Before Present), i.e., well after the LGM. Here, we report new AMS radiocarbon dates obtained on cut-marked bone samples identified during a comprehensive taphonomic analysis of the Bluefish Caves fauna. Our results demonstrate that humans occupied the site as early as 24,000 cal BP (19,650 ± 130 14C BP). In addition to proving that Bluefish Caves is the oldest known archaeological site in North America, the results offer archaeological support for the “Beringian standstill hypothesis”, which proposes that a genetically isolated human population persisted in Beringia during the LGM and dispersed from there to North and South America during the post-LGM period.


     
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  5. sculptor Valued Senior Member

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    or
    Horses arrived in the new world 23,000 years earlier than previously believed.
    or lasted longer here than previously believed?
     
    Last edited: Jan 19, 2017
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  7. iceaura Valued Senior Member

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    Horses were indigenous to NA at the time - species evolved here, over millions of years. They went extinct along with most of the rest of the large mammals (and many large birds) about the time of the last glacial retreat, having survived every other glaciation and interstade up to that time.
     
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  8. Fraggle Rocker Staff Member

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    Moose, bison, mountain goats and caribou/reindeer survived. As did their nemeses, such as brown bears and the wolverine/glutton.

    Sabretooth cats were once apex predators in North America, but I don't know their timeline. Same for the woolly mammoth.
     
  9. Yazata Valued Senior Member

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    Most of what I'm going to say comes from reading Cavalli-Sforza's chapter on the ancient Americans several years ago.

    Dating these kind of traces is very difficult and there seems to be a lot of controversy about whether these older dates are really accurate. But evidence does seem to be accumulating that human beings might have been present in the Americas, including South America, before the end of the last ice age.

    The best evidence I've heard of for very early ancient Americans comes from Chile. Interestingly, that's near the southern tip of South America. Which suggests that humans were widely dispersed in the Americas by that time. (Unfortunately, the date remains controversial.)

    Cavalli-Sforza is of the opinion that examination of the genetics of pre-Columbian American populations shows evidence of three different migrations. These are associated with linguistic divisions, first, the bulk of the American Indian population, second, the Na-Dene speakers in NW Canada down to Arizona, and third, the Eskimos and Aleuts.

    The Eskimos and Aleuts appear to be the most recent arrivals. The other two arrived in two waves associated with the last ice-age, lower sea-levels, and the Bering land-bridge.

    Cavalli-Sforza suggests that crossing this land-bridge would have been most likely at the end of the ice-age, or at its beginning. During the height of the ice-age, climactic conditions might have made the crossing more difficult.

    And he speculates that while it's probable that the Na-Dene speakers came across at the end of the ice age, sometime prior to 10,000 BCE, some question exists whether the rest of the American Indians' ancestors came across in a separate wave at roughly the same time (give or take a thousand years, maybe) or whether they came across much earlier, towards the beginning of the last period of massive glaciation, instead of its end.

    Apparently lots of work (genetic and otherwise) has been done to try to resolve this, but I got the impression that it's kind of inconclusive at this point.
     
    Last edited: Jan 22, 2017
  10. Fraggle Rocker Staff Member

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    I'm glad to run into someone else who knows about Cavalli-Sforza. I haven't read his work directly. But I encountered a PBS series in which some of his colleagues followed the migration paths he had charted, checking DNA at regular intervals.

    The most touching segment was a crew entering the enormous Navajo Reservation in Arizona and New Mexico. The Navajo teach their children that the tribe has always been right where it is now; that this is where the Creator put them. While the chief was arguing with the scientists, his son was riffling through the photos they had brought from other regions, when he stopped dead, pulled one out, and said, "Dad, this guy looks just like Uncle Ernie."

    He inspected it for a long time. Then he turned to the camera, put on his most solemn face, and said, "Then I guess what you white men have been trying to tell us is true. We really are all brothers."

    The man in the photo was a member of the Yenisei tribe in Siberia. Linguists have spent years trying to find a solid relationship between Yenisei and the Na-Dene language family. Na-Dene languages are spoken in western North America, from Arizona (Navajo) to Alaska (Tlingit).
    One anthropologist pulled out a calculator and determined that for this to have happened, the migrants had to be walking south at an average rate of about three miles per year. That leaves them plenty of time to leave some folks behind in new, permanent habitations with plenty of food around, but still it's quite a feat.
    Yes, this is a well-established hypothesis that's supported by geography and by the style of tools left along the way.
    Yes, they can still recognize their cousins in Siberia, and linguists can easily identify the familiar relationship of their languages.
    There's a contingent of anthropologists who remind us that boat technology was well advanced in Japan, Korea, the other islands off the shore of Asia, and even in (what is now) China itself. It's not unrealistic to hypothesize people sailing to Alaska.

    I recently read (in either National Geographic or the Smithsonian magazine) of an ancient site in Alaska that had been excavated. As usual, the human remains were in good condition and they were able to analyze the DNA. The anthropologists were shocked to discover that the people who comprised this community had ancestors from four or five different regions in Asia. They might have arrived many centuries apart.
    During a warming period, of course, it would have been much easier to approach by water.
    This correlates with the hypothetical relationship between the Yeniseian and Na-Dene people.
    We have plenty of evidence for other people arriving from different places. The Vikings are the most recent prior to the Spaniards, but there's evidence of at least one Atlantic coastal village built around 14000BCE by the Solutreans, a people whose technology places their origin firmly in western Europe. It wasn't discovered until recently, because in 14000BCE, sea level was much lower. So the village is several miles out to sea and well below today's sea level.
    Yes, it's a shame that those folks didn't leave their cellphones behind.

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  11. iceaura Valued Senior Member

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    Or paddling. And all the way to Tierra del Fuego, river mouth to river mouth. And with small portages, up the Columbia and the Colorado to the divide and down to the great, meat-rich and lake-spotted central plains, and across Central America at a couple of the low spots, to the Caribbean and everywhere.

    Be interesting to know how they first reached the mouth of the Mississippi - downriver from Lake Agassiz, downriver from the frontage lakes of New England, around the coast from New England, around the coast from Nicaragua. But they were coming.
    People on foot move around a lot faster and farther than civilized folks tend to imagine. Just following big game on its travels can take hunters hundreds of miles a year.

    People are stopped from wandering by other people these days, and hunting is a hell of a lot easier when the animals don't know what's up. With an unoccupied continent in front of them, they would have covered ground in a hurry - in hundred klick jumps, easily, per teenage generation. And these people were probably reproducing faster than anyone on earth ever has, before or since. They had pressure to move and nothing to stop them.

    The settlement of the US west of the Appalachians by English speaking white people was done essentially on foot, by young folk getting out of the house, and covered 3000 miles in 60 years.
     

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