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I saw a documentary on humans and Neanderthals about a decade ago and it melted my mind. Absolutely fascinating that there was another species that was very sim

• pavlov 3y ago
  I kind of feel the opposite: the crazy part isn’t that we had relatives, but that we’re the only remaining species of the Homo genus. It’s somehow unsettling that we are the only ones left. Most large mammals come from a genus with many cousins. We’re alone either because we killed the others, or because intelligence actually has a hard time surviving in nature. Neither is really good news for us.
  • throwup238 3y ago
    The taxonomy of archaic humans is debatable to say the least so "we are only the ones left" may just be an artifact of 19th century anthropology and prestige chasing. Realistically the genetic variation between the average human and Neanderthals is only about twice the variation within the modern human gene pool. Compared to our nearest primate at 10-50x the difference depending on how you measure. Given the number of genetic bottlenecks we have evidence of in our past, we may all be the same species and the modern human is just the last surviving group of inbred Homos.
    • zoklet-enjoyer 3y ago
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    • pavlov 3y ago
      Isn’t “genetic bottlenecks” another way of saying that intelligence has a poor track record of surviving?
      • kombookcha 3y ago
        Not really - genetic bottlenecks aren't a feature of intelligent animals, it's a feature of a population that's undergone some kind of very dramatic pressure event like catastrophic loss of habitat or mass illness. Bottlenecks are more likely to be an issue for species with a limited range, population and a slim range of survivable conditions. Intelligence has a way of expanding those ranges by making you more equipped to access otherwise inaccessible resources. Think of elephants navigating between watering holes during droughts, crows using tools to fish out hard to get food, or orcas using sophisticated hunting techniques to get at prey they otherwise could not. Intelligence adds flexibility, and flexibility is especially useful under pressure.
    • mjfl 3y ago
      which implies that there are humans alive that are genetically as far apart from each other as the average human was from the average neanderthal (i.e. statistically there probably exists humans who's separation from each other is twice the average distance).
  • hyggetrold 3y ago
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    • ffgjgf1 3y ago
      As far as we can tell Neanderthal populations were very small and fragile (very low genetic diversity) to begin with. So it’s not unlikely that modern human just absorbed them. A bit like the hunter gatherers who pretty much disappeared in much of Europe during the Neolithic
    • s1artibartfast 3y ago
      Seems silly, but why Genocide specifically? What does that word mean to you and what do you think that would look like?
      • hyggetrold 3y ago
        Means pretty much the definition: "the deliberate killing of a large number of people from a particular nation or ethnic group with the aim of destroying that nation or group." So yeah...in my crazy conspiracy theory (which I don't take very seriously) I think Neanderthals may have been systematically hunted down and exterminated. When you study human history you soon discover that no matter the era, we have a total fondness for killing each other.
        • s1artibartfast 3y ago
          Genocide really depends on the motivation. If we simply ate them to extinction, that wouldnt be genocide. Even expanding and taking their lands would be a stretch, as long as the destruction is incidental
          • hyggetrold 3y ago
            Um...wow. Might makes right?
            • 3y ago
  • mjfl 3y ago
    they weren't necessarily killed off, rather blended into the human population through conquest and wife-stealing and the resulting interbreeding.
    • mistrial9 3y ago
      indeed, wife-stealing appears to be a very successful formation over long periods of time.. woe to the peaceful
      • ffgjgf1 3y ago
        If anything it was the opposite: > No evidence of Neanderthal mitochondrial DNA has been found in modern humans.[30][31][32] > This suggests that successful Neanderthal admixture happened in pairings with Neanderthal males and modern human females Of course it also might mean that human males and Neanderthal females can’t produce viable offspring
        • mjfl 3y ago
          It doesn't follow that if human males stole Neanderthal wives sometime in the past, that you would necessarily see Neanderthal mitochondrial DNA in present populations. Consider a serial 'wife-stealing' human culture. One generation of human males leaps upon a small population of Neanderthals, killing the men and stealing the women. The next generation, a new group of half-neanderthal males leaves the colony in search of wives, finds a human group, kills the men, and steals the women. The children of this generation will be 1/4 Neanderthal with no Neanderthal mitochondrial DNA. Imagine that the first colony gets wiped out, as most ancient communities were. There you go.
          • ffgjgf1 3y ago
            > There you go. So either it didn’t happen at all or if it did it happened in on a much smaller scale than the opposite (Neanderthal male and human female)? Also this scenario is completely unsubstantiated conjecture so hardly worth discussing.
  • shagie 3y ago
    > or because intelligence actually has a hard time surviving in nature. Alas, I can't find it now... there was a book that I read (Bear / Brin / Benford as the author I believe... maybe Baxter... one of the great Bs I'm sure of) about the matrilineal line from a small shrew like animal in the time of the dinosaurs through neanderthals to modern times... and beyond. Part of the "and beyond" was the theme that intelligence and our brain is an extremely expensive organ to maintain (our brain consumes about 20% of the calories that we consume a day https://www.ncbi.nlm.nih.gov/pmc/articles/PMC124895/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC124895/ ). After some catastrophe that reduces the energy budget that animals can use... well, intelligence is one of the things to go. (Late edit: It was Baxter - https://en.wikipedia.org/wiki/Evolution_(Baxter_novel) https://en.wikipedia.org/wiki/Evolution_(Baxter_novel) )
  • s1artibartfast 3y ago
    I think that any forecasts are probably reading too much into a limited data set. Intelligence does have an incredibly hard time surviving in nature. Humans are hyper-optimized for it. We are far weaker than chimps, and burn 30% more calories. We are slow reproducing k-strategists, with infants that are helpless for years. That said, Humans are planet level apex predators, and universal omnivores that consume everything whales to yeast and synthetic foods made from elemental materials. Over the course of our existence, our capability for growth has vastly overshadowed any downside from intra-species hostility. We are also the most cooperative and social animal that has ever existed. This is a pretty strong position to be in, and certainly better than just about any other animal sharing the plant.
    • polishdude20 3y ago
      Yeah what blows my mind thinking about it is just how we are the only species that communicates across continents.
  • golergka 3y ago
    Or may be because we lived together for so long that individual differences disappeared and averaged out as people intermarried and had a lot of mixed babies. I'm not saying that this necessarily happened, only that the burden of proof for your theory should be higher.
    • mrangle 3y ago
      This is what happened, logically speaking. Though not averaged out in a balanced manner: instead, to the degree that Neanderthal genetics comprise anyone's genome. Not to say that there weren't interspecies genocides, but we interbred with them and then outcompeted, for resources, the pure species into extinction generally speaking. Which was inevitable, parallel to how homo sapien lineages also die out from simply being outcompeted. It is likely that the Neanderthal genome was outcompeted down to a percentage at which it was and is competitive. 50-50% Neanderthal-Modern Human? No dice, Darwin. It had to be reduced to a few percentage points, at which point individuals started being competitive. Was the last pure Neanderthal pair murdered, did they die from starvation, or did they just refuse to have kids? It could have been any of those, but the general procedure was likely defined by resource competition. And Neanderthal isn't the only alien-homo genome mixed with that of modern humans.
  • namlem 3y ago
    Were Neanderthals more genetically different from typical Homo sapiens than modern day pygmy peoples? Iirc, Khosians also diverged genetically from other regional peoples.
• hobs 3y ago
  Don't forget that we intermixed with the Denisovans too.
  • bjackman 3y ago
    Based on modern DNA patterns there also seems to have been at least one other major population group around the same time that we have not found any remains of, which was related to both Sapiens and Denisovans. They probably lived mostly around southeast Asia. (Neanderthals were mostly in Europe and Denisovans are thought probably to have generally inhabited northern Asia). I can highly recommend The World Before Us by Tom Higham, it goes into the history of the archaeology and science and also goes over a pretty up-to-date understanding of the topic of recent Hominin evolution. (Also, it's very likely I've misconstrued some of it in my paragraphs above, apologies if so).
  • deleted 3y ago
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• mjfl 3y ago
  another interesting fact is that modern Europeans are descended from 4 distinct populations which were as genetically distant from each other as modern Europeans are from Asians: Western hunter gatherers, anatolian farmers, eastern hunter gatherers, and eurasian steppe herders. David Reich goes into it in his book 'Who we are and why we got here'.
• amelius 3y ago
  > another species that was very similar to us that we interbred with Ok, if it is so similar to us and we interbred with it, then why is this so special? Might as well call it the same species by stretching the definition a little.
  • itronitron 3y ago
    Yeah, the interbreeding must have been uncommon as otherwise over 10,000 years there wouldn't be any meaningful distinction (I assume).
    • acchow 3y ago
      Either uncommon or many of the attempts were unsuccessful.
      • fuzzfactor 3y ago
        Alternatively, it could have been so common that Neanderthals were fully assimilated far more rapidly than could be preserved in the fossil record. Especially that limited part of the record that has been so far revealed.
  • meheleventyone 3y ago
    That is one of the issues with species as a concept. There are quite a few differing definitions which are all useful. It’s typically discussed as the ‘species problem’.
  • acchow 3y ago
    We were only "separate" species because for a period of tens of thousands of years we did not interbreed and developed independently due to physical separation. But we could and did interbreed when the physical separation was crossed. Despite the separation, we remained similar enough genetically that interbreeding was possible. Were there a higher number of miscarriages than between 2 humans? We will probably never know.
    • 3y ago