Neanderthals and the beginnings of us

The Smithsonian has an interesting article up on what we currently know about Neanderthals.  The article details some of the internecine battles that always seems to be a part of the paleoanthropology field, in this case focusing on the capabilities of Neanderthals, whether they had art, religion, and other qualities of modern humans.

Our view of Neanderthals has undergone a radical transformation from when they were first discovered in the 19th century.  Then they were thought of a ape-men, large lumbering brutes who probably didn’t have language, clothing, or brains to speak of.  As recently as a few decades ago, in the movie Quest for Fire (one of my favorite movies, despite its flaws), Neanderthals were portrayed as mental inferiors who often acted like monkeys.

But in science, evidence always has the final word:

A new body of research has emerged that’s transformed our image of Neanderthals. Through advances in archaeology, dating, genetics, biological anthropology and many related disciplines we now know that Neanderthals not only had bigger brains than sapiens, but also walked upright and had a greater lung capacity. These ice age Eurasians were skilled toolmakers and big-game hunters who lived in large social groups, built shelters, traded jewelry, wore clothing, ate plants and cooked them, and made sticky pitch to secure their spear points by heating birch bark. Evidence is mounting that Neanderthals had a complex language and even, given the care with which they buried their dead, some form of spirituality. And as the cave art in Spain demonstrates, these early settlers had the chutzpah to enter an unwelcoming underground environment, using fire to light the way.

It seems clear now that if we were to encounter Neanderthals today, they might look a bit strange to us, but we would quickly come to regard them as people.  Indeed, that appears to be what our ancestors did.

The real game-changer came in 2013, when, after a decades-long effort to decode ancient DNA, the Max Planck Institute published the entire Neanderthal genome. It turns out that if you’re of European or Asian descent, up to 4 percent of your DNA was inherited directly from Neanderthals.

4% may not seem like much, but my understanding is that it represents a lot of interbreeding between Homo sapiens and Homo neanderthalis.  These weren’t one off encounters, the results of deviants from one or both species.  It indicates pretty wide integration.

Decades ago, there were two prevailing theories about how modern humans evolved.  One held that we had gradually evolved from earlier Homo species, primarily Homo erectus, throughout the world, with ongoing genetic exchanges.  In this model, called Multiregional Evolution, Europeans evolved mostly separately from eastern Asians who evolved mostly separately from Africans, etc.

The other view, called the Replacement model, or Recent African Origin theory, held that modern humans had evolved in Africa, and then sometime in the last 50,000-100,000 years had migrated out and spread throughout the world, displacing any other Homo species they encountered.

The debate between these two views raged on for decades, with the evidence gradually growing in favor of the Replacement model, before genetic research finally weighed in on it and sealed the deal.  It turns out that modern humans evolved in Africa within the last 200,000-300,000 years.  All of us today are descended from these Africans.  A branch of humanity migrated out of Africa sometime between 60,000 and 80,000 years ago, spreading throughout the world.  All non-Africans are descended from this branch.

But while the Replacement model was mostly right, it wasn’t entirely right.  As mentioned above, further research showed that non-Africans have DNA from other branches of humanity.  European ancestors interbred with Neanderthals, and Asian ancestors probably interbred with another branch of humanity called Denisovans.

One of the theories about why these other branches of humanity died out, prevalent until just a few years ago, was that Homo sapiens probably wiped them out.  I have to admit that this dark genocidal theory seemed plausible to me at the time.  Neanderthals in particular had been around for hundreds of thousands of years, only disappearing when modern humans came around.

But it now strikes me as more plausible that Neanderthals weren’t wiped out.  They were assimilated.  This is referred to as the Assimilation Model in the article.  The population of Neanderthals was never more than a few thousand individuals, while the incoming Homo sapiens population was reportedly in the tens of thousands.  It seems likely that what happened was some degree of interbreeding, merging, and assimilation.

I’m sure that doesn’t mean it was all sweetness and light.  Homo sapiens were an invading force.  I’m sure there was conflict, and some of it was probably brutal.  There’s too much continuity in violent behavior from other primates to humans to think it wouldn’t have happened.  But we’re also a pragmatic species, one whose members will make alliances when it’s the best option.  It seems clear that happened in at least some portion of the encounters.

All of which indicates that Homo sapiens and Neanderthals had enough in common to recognize each other’s humanity.  Which also means that their common ancestor, Homo heidelbergensis, who lived from 700,000 to 300,000 years ago, likely had many of the qualities we’d recognize in people.  There’s no evidence they had what’s now called behavioral modernity, including symbolic thought, but they must have had a lot of what makes us…us, including perhaps an early form of language, or proto-language.

But this is a field where new evidence is constantly being uncovered and paradigms shifted, so we should probably expect more surprises in the years to come.

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13 Responses to Neanderthals and the beginnings of us

  1. As an author of books on catastrophic pole shifts – I must point out that periodic cataclysms seem to devastate the world in cycles linked to our axial precession cycle of about 25,800 years – including half cycle events (12,900 years apart) midway through – when the last great civilization was allegedly destroyed – and even quarter cycle events (last one possibly about 6,000 years ago.)

    I have read before that prior to 52,000 years ago, Neanderthal DNA had as much variety and genetic diversity as we do today – but that their population was suddenly and drastically reduced, and that after 52,000 years ago they had very limited diversity comparable to Iceland today. Neanderthals were wiped out about 26,000 years ago – probably a one-two punch from a catastrophic pole shift, with Homo Sapiens survivors adapting better to the changes and ending Neanderthals as a distinct people in the immediate aftermath.

    Unfortunately we are due for another pole shift catastrophe soon (some clues suggest various years between now and 2060) and I hope Homo Sapiens doesn’t come close to extinction.

    Liked by 1 person

    • Appreciate your comment. That doesn’t match up with what I’ve read, either in terms of what happened with the Neanderthals or the effects of pole reversals.

      There was a supervolcanic eruption 75,000 years ago in Lake Toba in modern day Indonesia, the atmospheric effects of which may have led to a population crash down to a few thousand individuals. Some think it might explain the lack of genetic diversity in modern humans.

      And we certainly are capable of bringing catastrophe on ourselves if we don’t learn to control how we treat the environment.

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  2. Callan says:

    So Cain ingested Abel?
    Works for the vampire myth as well

    Liked by 1 person

  3. James Cross says:

    This somewhat relates to my last post on my blog and more so to a post I keep intending to do but haven’t yet.

    https://broadspeculations.com/2019/03/20/out-of-south-africa/

    Assimilation, in the genetic sense, is not inconsistent with modern humans wiping out related humans. The typical pattern in chimpanzees and human hunters and gathers is for the aggressor group to kill the adult males of the attacked group, rape the females and/or take them as slaves, and possibly take some of the children. In the course of this, some offspring of the females would be born and allow to live, particularly I suppose if they had characteristics sufficiently like the aggressor humans. So these were not likely alliances in most cases.

    I say it is doubtful Homo sapiens recognized the humanity of Neanderthals. After all, Nazis didn’t recognize the humanity of Jews. Colonial Europeans didn’t recognize the humanity Africans. The word for human and the word people use to refer to themselves is the same in many languages.

    Liked by 1 person

    • Maybe you’re right. It’s possible. We may never know the details of how it happened. Although if it happened specifically in the way you describe, with all Neanderthal DNA coming to us from the female line, maybe it could be detected in how much mitochondria DNA we specifically inherited from Neanderthals.

      But while history certainly implies your scenario could be true, it also has plenty of examples of less brutal interactions. I can’t see any reason to suspect that all the reactions of all the tribes that came into contact with other branches of humanity were consistently the same. There would have been no coordination. Which to me means that they probably responded in a variety of ways, sometimes brutal, other times pragmatic, and probably often in combinations.

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      • James Cross says:

        Sure there were probably pragmatic encounters too.

        Ironically, perhaps, the characteristic that may have allowed modern humans to succeed over others may also be what divides us today. When we began to live in larger groups, we needed something other than blood to unite us. Language, cultural symbols, rituals, all played a role in uniting a group. However, it also led to an increased antipathy toward those outside the group – those with different languages and customs.. With larger and more cultural homogeneous groups came the ability for more innovation and an increased ability to pass the innovations to the next generation. Among the innovations were weapons and the softer organizational technologies that would allow a group to triumph over rivals in war.

        There were probably aspects of this in Neanderthals, Denisovans, and other archaic sapien groups.

        I think there could have been a leap of some sort in this ability in Southern Africa about 100K years ago. As shown in the previously linked post, some part of this group migrated to East Africa which now appears to be the origin point of out of Africa migration that led to humans “out competing” (as it is often described) the others. This relatively small group from Southern Africa may be what accounts for evidence of the population bottleneck frequently attributed to Toba.

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        • Jonathan Haidt says the religion both binds and it blinds. I think the same thing can be said about culture overall. It binds us in ways that make society work, but it blinds us to the humanity of people outside of that culture. The more nationalistic someone is, the more attached they are to their particular culture, the harsher their view is typically of other cultures.

          On the population bottleneck, I’m not sure the migration pathway really explains it. Yes, it did create a bottleneck for non-Africans, and ethnic Africans are more genetically diverse than the rest of humanity, but as I understand it, humanity overall including Africans is less diverse than most species.

          That said, the Toba theory has its own problems. For one, I’m not sure the timelines for it really line up. Modern humans might have already been out of Africa when it happened. And if it was the cause of a population collapse for humans, why wasn’t it also one for other species? And not every relevant expert agrees that the evidence it caused a volcanic winter is compelling.

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          • James Cross says:

            Of course, a lot depends upon what we define as modern humans. That there were anatomically modern humans outside of Africa before Toba is probably right.

            This blog has a lot of info on this. He (or she actually not sure) doesn’t post often but thinks there is evidence of a migration before 100K ago.

            https://6000generations.wordpress.com/

            But the question boils down to whether all of the humans of the skeletons that are Homo sapiens are equal in behavioral capabilities. The fact that humans as a whole lack genetic diversity (as you note) compared to other species does suggest the main line of humanity comes from a relatively small group and possibly not too long ago. The Toba theory does have problems. In a correspondence with one of the authors of the study I linked to, he stated the below when I asked about bottleneck being the result of this migration:

            “Yes and no. There was a massive founder effect when modern humans left Africa, but they were basically East Africans – our suggestion is that they had prior to that been acculturated by incoming people from the south.”

            However, when I asked about whether the group that migrated out of Africa were East Africans from prior to this possible contact with those from the South or possibly predominately genetically those originally from the South he wrote:

            “I’m not sure it’s possible to say because of the severe lack of useful Y data from Africa at the moment. Or maybe it’s just me not being able to make sense of it all.”

            So the scenario suggested in the article is that modern humans from the South migrated to East Africa and passed on the cultural traits that eventually spread around the world. An alternate scenario is those from the South may have had genetic traits that gave them a superior cultural ability. Perhaps greater language facility might have been a key part of it. This gave them an ability to make superior technology and organize more efficiently. The contact, in this scenario, with the East Africans might have predominately been war and extermination. A pattern similar to this may have repeated as we moved around the world and encountered those we thought to be less than human.

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          • Thanks for the blog link. Apparently I’d visited it before since at some point I liked their About page.

            From what I understand, there were remains of anatomically modern humans found in the Levant from around 100,000 years ago, but it’s not clear they survived and contributed anything to our gene pool. They appeared to be a dead end genetically. Of course, they would have co-existed with populations of Neanderthals at the time, so they may have contributed indirectly if there was interbreeding. If they weren’t wiped out by them.

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  4. GlennDC says:

    The hard-core view is that the violent assimilation suggested by Mr. Cross is likely correct per the genetic evidence, a recent example of which is the disappearance of Iberian male DNA following the invasion by the asians about 4 to 6 millennia, give or take, ago. You should visit Mr. Cochran’s acerbic site, he posts often with dystopian, but likely realistic input about the meaning of rapidly multiplying genetic evidence. https://westhunt.wordpress.com/

    Liked by 1 person

    • Thanks for your views!

      Interesting site, although as you note, not someone prone to diplomacy. What is it about paleoanthropology that leads so many people involved with it to be acrimonious?

      Like

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