First Peoples and Neanderthals

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This weekend, I finished off the last of the ‘First Peoples‘ PBS miniseries on prehistoric humans.  If  you’ve watched other documentaries on human prehistory and found them interesting, then you’ll want to watch this one to get the latest findings.  It was fascinating.  (A lot of people have mentioned ‘Becoming Human‘ to me, which I’ve seen and enjoyed, but its content is now dated by a few years.)

I did find the sound editing in the first hour to be poor.  Often I couldn’t hear what the narrator was saying over the music or sound effects.  Hopefully they’ll fix that by the time the series is available in other venues.  If not, don’t let it deter you from watching the rest.  It gets much better after that first hour.  And the actual content of that first hour, on prehistoric native Americans, is fascinating if  you can bear with it.

In the final episode, we see anthropologist John Hawks discuss a theory about Neanderthals that I wrote about a few months ago, that they actually didn’t go extinct, but were assimilated into Home sapien societies.

A couple of decades ago, there were two major theories on the evolution of Homo sapiens.  One, called the Multiregional theory, posited that modern humans evolved throughout the world, with gene flow between the continents keeping humanity one species.  The other was the Replacement, or Out of Africa theory,  which held that modern humans evolved in Africa and then spread throughout the world, replacing other archaic human species such as the Neanderthals.

In recent years, the evidence seemed to swing decidedly in favor of the Replacement model.  All of the oldest remains of modern humans were found in Africa, and all archaeological signs of behavioral modernity throughout the rest of the world were less than 50,000 years old.  Genetic studies revealing the prehistoric migrations that Homo sapiens followed seemed to be the nail in the coffin of the Multiregional model.

All of which didn’t have modern humans looking too good in our relationship with other archaic humans.  It was starting to look uncomfortably like we had invaded their turf and drove them to extinction, either directly through conflict or indirectly through resource competition.

Then someone sequenced the DNA of Neanderthals and discovered that all ethnic non-Africans (from relatively recent times) share between 1% and 4% of their DNA with Neanderthals.  There was some discussion that maybe that shared DNA went back to the common ancestor of Homo sapiens and Neanderthals, but most scientists now see this shared genetics coming from intermixing.

In other words, Homo sapiens and Neanderthals mated.  If they did that, these two groups must have seen a lot more humanity in each other than had previously been supposed.  Neanderthals, since their discovery, have moved from an ape like conception to a branch of humanity that most of us have inherited from.

As Hawks discussed, Neanderthal population was probably never more than a few thousand individuals, while Homo sapiens migrating into their regions numbered in the tens of thousands, maybe even hundreds of thousands.  Neanderthals didn’t so much as go extinct as get swamped and assimilated.  Unless your ethnicity is African (again from recent historical times since we’re all Africans if we go far enough back), then you are part Neanderthal.

Depending on where your ancestors lived, you also may have bits of other archaic human population genetics in you, such as the Denisovans.

So, the verdict of evidence appears to be that the Replacement model was mostly right.  All of us are mostly descended from Africans, including the parts that make us modern humans.  But the Multiregional model was not completely wrong either since most of us have DNA from other branches of humanity.

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8 Responses to First Peoples and Neanderthals

  1. My students’ reaction to this was mostly “does that mean we’re primitive?”

    Neanderthals have a PR problem, it seems.

    Liked by 1 person

  2. amanimal says:

    Hi SAP, how’s your summer progressing(and the shoulder)? I’ve watched 4 of the 5 epidodes – fascinating stuff – was reminded seeing this today:

    ‘The mystery of Neanderthals’ eyes’ http://www.bbc.com/earth/story/20150805-neanderthals-strange-large-eyes

    … for which John Hawks was interviewed. The bush baby picture(more specifically its hands) is for me a pretty powerful reminder of our connection to, not only our primate order, but the larger group of limbed, grasping creatures as well.

    ‘The Beautiful Complexity of Animal Hands’ http://scribol.com/environment/the-beautiful-complexity-of-animal-hands

    (sorry, kind of drifted off-topic there 🙂 )

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    • Hi Mark,
      My summer’s been busy as all heck. But it seems to be tapering down somewhat. My shoulder is a lot better. The exercises finally did their thing, but only after I discovered that doing them every four days, rather than every other day as prescribed by the doctors and therapists, allowed enough recovery and strengthening time.

      How’s your summer been? I know you were busy yourself earlier this year. Hope everything’s settled down.

      Thanks for the articles. Interesting. I’ve come to see the hands as one of the unique things about primates. It’s what allows us to manipulate the environment, far more than other animal types, at least on an individual basis. So I was a bit surprised by the gecko and frog pictures.

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      • amanimal says:

        Things have quieted and settled and we’re busy enjoying the short Maine summer. Good news on the shoulder!

        This time of year we have raccoon that visit nightly to clean out the dry cat food and water we have out for visitors(including them). Now by human, even primate, standards they’re clumsy fumbling little things with their hands, but the fundamental structure of multiple segmented “fingers” is obvious and they use them to great effect in feeding. And as you saw you can even leave the mammalian world and still talk about “hands”, more grasping than manipulating in nature, but that’s where it had to start. There are some really amazing “grasping mechanisms” in the insect world, but now I’m really drifting …

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        • I’d imagine summers are pretty mild up there, a little compensation for the brutal winters you guys have. Down here (Louisiana), we’re having regular highs of 100F. Sometimes it rains to cool things off, but that’s been limited in the last month or so.

          I wonder sometimes how likely something like hands were to evolve. Humans lucked out as being the most intelligent and one of the most dexterous species on the planet. It’s hard to imagine our success without that combination. Dolphins, no matter how intelligent they might evolve, seem like they could never be able to manipulate their environment to the extent we can.

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          • amanimal says:

            I may have mentioned(a long time ago) visiting NO in Aug(I think) as a teenager. I imagine by LA standards we don’t even really have summer up here 🙂 When it’s that hot and humid down there, are people even able do anything even moderately strenuous outside? My recollection of NO was of going from the air-conditioned hotel to air-conditioned stores, to air-conditioned restaurants(and taking salt tablets). Beal street was the only place I remember that was NOT air-conditioned(the street itself, I was underage and couldn’t get in anywhere, but I could still listen 🙂 ).

            On the likelihood of the evolution of the hand, with resource rich arboreal(vertical) environments to exploit, I’d think almost inevitable, but as you note, our manual dexterity is leagues beyond the competition and, I agree, fundamental to our success – brings to mind thoughts of Swiss watches and open heart or brain surgery(any kind of surgery really).

            (or trying to open those little slider latches on necklaces my wife or daughter wear – besides my reading glasses it couldn’t be done without the mix of visual acuity and motor control, a “big”/”intelligent” brain, and a small bit of fingernail length – close direct lighting also helps)

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          • This time of year there are lots of heat advisories with admonitions to stay hydrated. Most people who have to work outside try to get it done either in the early morning or at night. I once took up jogging. Doing it in the summer was brutal. I tried to do it in the evenings (never been a morning exerciser), but still finished covered in sweat with bugs stuck to me.

            I tend to think the Fermi paradox is answered by how long it took on Earth for a species to evolve that was both intelligent and dexterous. I suspect the combination is incredibly rare in the universe. (And I’ve never been any good with those latches, even when I had good eyesight. 🙂 )

            Liked by 1 person

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