• Blimey.

    https://www.theguardian.com/science/2021/may/16/tiny-traces-of-dna-found-in-cave-dust-may-unlock-secret-life-of-neanderthals

    Still some things that annoy me a little in the article--not the fault of the researchers.

    I don't think that either Denisovans or Neanderthals were different species from 'modern' humans. I think humans must have differentiated by where they dispersed to, first within Africa, and then in Europe, Asia, etc. There must have been some very early human migrations, resulting in populations that looked different and talked differently (because I'm certain that all the early humans we talk about will already have had languages). I suspect that migration across the Mediterranean was rare, as was migration across Sinai, and so groups remained apart for long periods, with the population of Europe always quite low, but not nearly long enough to become different 'species'.

    Also, I don't like the language that makes it seem as if early humans were some kind of prehistoric curiosities. They were people just like people today, just with a different standard of technology and different health adaptations. We tend to concentrate on the places where it's more likely that fossils are preserved, and we now seem to be able to use even cave dust. However, I'm certain that 'cavemen' would already have had the ability to build wooden shelters, and that they mainly lived in those, even in colder climates. Organic material rots away so quickly, though, that it would take an absolutely extraordinary combination of factors to preserve it from tens of thousands of years ago, though. Caves were undoubtedly inhabited because they were there, but many will have had ceremonial functions. Cave bears and other creatures, like those Italian hyenas, were still serious threats to humans, and that will have made many caves unattractive for humans to live in permanently. Other things I suspect are that I wouldn't be even slightly surprised if very early humans were already able to build boats or rafts of some description to travel to islands like Madagascar, although inevitably this would have taken a lot of trial and error.

    Migration generally occurs when populations get too large for an area or when there's conflict, and both of those will already have been facts of life tens of thousands of years ago. I suspect that people will have lived in the area that is now the Sahara in particularly large numbers, and will have exhausted it at some point, also driven by climate change, and large groups will have left constantly, as there will have been a lot of conflict for dwindling resources. This will have been at a time when Europe and Asia will have become warmer, and older and newer incomers will have mixed quite a lot. And I still don't think the Neanderthals ever became 'extinct'. No doubt many will have been killed in conflict, but their smaller population basically intermarried with newer incomers and forms the ancestry of many people alive today.

    All just hypotheses and conjecture, not based on any evidence, but it will be fascinating to see what that cave dust analysis can show.

  • I was taught by Chris Stringer when I did an Anthropology degree. This was before they had the genetic evidence but the thinking was that there probably had been Sapiens and Neanderthal interbreeding. Technically the article is correct in referring to Denisovans and Neanderthals as different species - I don’t think it’s meant to be derogatory and note that Neanderthals had larger brain cases than Sapiens. There was a famous site where they’d buried a child with flowers which I remember being haunted by as a student so the standard image of the brutish caveman was discredited a long time ago but it’s still a persistent myth. William Golding’s novel The Inheritors is a rethinking of that caveman myth and implies that maybe the ‘wrong’ human species made it to the present.

  • Yes, the myths definitely need busting. To explain what I mean a little more: No doubt there were differences between Neanderthals, Denisovans, and 'Sapiens' (and I've never understood why differences in brain case size are considered significant), but what I'm mainly concerned with here are definitions, i.e. how much difference is possible within a 'species'.

    (NB I also don't like using the word 'interbreed' when speaking about people, although when I first started to think about this, I used it myself.)

    Now, I realise this may not be current thinking any more, but I always thought that 'species' was defined as 'can produce fertile offspring with one another', between male and female in the case of mammals, for instance. All I've ever read suggests to me very strongly that all human groups were able to produce fertile offspring together, and that they are all woven into our story. I seriously doubt that any group of humans ever fully 'died out' or 'became extinct'. Sure, they bashed each others' heads in all the time, like humans have always done, but they also produced fertile offspring.

    My question has long been how much difference remains after that to still call different humans members of different 'species'. What does 'species' mean if it's not special enough to procreate alone? I strongly suspect that it's simply inapplicable to humans. I think that if we were to find any evidence of different human species, it would be in the very early stages of our evolution, i.e. probably in Africa, but probably not outside it. Obviously, we have various extremely old fossils from across a long, long period of time, and it's possible that those at the start of the development would not have been able to produce fertile offspring with those at or towards the end of the chain, because by then significant enough changes in their composition had taken hold, but I think it most likely that people would always have been part of one contemporaneous species.

    Again, I'm no expert, just an armchair conjecturist, and one reason why I care about the answer to this is because I think establishing beyond doubt that there have never been any really significant differences between people would help to some extent with the fight against racism.

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