Gene Expression

Were Neanderthals our enemies or lovers?:

One difficulty in working out how these ancient humans rubbed along is that there is a lack of clear evidence of close encounters. That changed two years ago when a paper was published by Prof Paul Mellars, of Cambridge University, and his student Brad Gravina, suggesting the two kinds of human lived together at Grotte des Fées at Châtelperron in France.

The study was criticised but the Cambridge team published a detailed rebuttal. “The importance of the new paper is that it confirms at least 2,000 years of coexistence/overlap between Neanderthals and modern humans in this one small region,” said Prof Mellars. “This is the only direct, unambiguous evidence of this so far.”

Comments

  1. #1 Anne Gilbert
    July 31, 2007

    This article seems to be full of, well, not exactly factual errors, but a bunch of suppositionns(unlike our ancestors, who were dark-skinned. . . .). We don’t know what “our ancestors” looked like. We don’t know what Neandertals looked like, either. Then they go into a lot of detail about the “tooth growth” differences, which may or may not be real; they certainly have been disputed. And other things, as well. Neandertals were “different” — in some ways, but then, you have to remember that some 50-30,000 years ago, a lot of things were “different”. And populations were smaller. There may even have been real races, in the biological sense, of which Neandertals were obviously one, if this is true. We just don’t know. I’d sure like to read any paper Mellars and his colleagues have put out on this. The Telegraph article is one of those “science journalist” reports that makes me want to *scream*!
    Anne G

  2. #2 razib
    July 31, 2007

    but a bunch of suppositionns(unlike our ancestors, who were dark-skinned. . . .

    that one probably isn’t. MC1R exhibits deep time depth as a consensus sequence amongst tropical peoples, no matter their phylogenetic relationship. IOW, light skin is derived.

  3. #3 Sandgroper
    July 31, 2007

    A variant of the detestable “Did our ancestors make love or war?” headline variety. It seems to rule out rape, forcible abduction/detention and uneasy coexistence in shared territory, all of which have occurred much more recently among humans.

    Co-occupation at low population density of a region might not imply the same as sharing the same cave in a neighbourly manner, particularly by two groups with different hunting/gathering strategies and even different prey species. I’m with Anne, seeing the paper would be of interest.

    And no mention of the evidence for introgression by the Telegraph.

  4. #4 toto
    July 31, 2007

    The paper by Mellars and Gravina on “interstratification” of Neanderthal and modern artifacts is at Nature. A rebuttal is at PNAS. The rebuttal of the rebuttal is also at PNAS.

    Oh, and if Neanderthal introgression really did occur, it must have been in Southwest France… Here’s the definite proof!

  5. #5 John Emerson
    July 31, 2007

    Both, obviously. There’s no other way it can be. “We marry the people we fight”.

  6. #6 Sandgroper
    July 31, 2007

    True enough, JE. Better than marrying someone friendly and then fighting afterwards.

    What interested me about the introgression thing is that it seemed to come from modern human male/neanderthal female.

    That’s the opposite of what I was expecting. If so, I think we could just about rule out forcible insemination, just on biomechanics.

  7. #7 Steve C
    July 31, 2007

    What interested me about the introgression thing is that it seemed to come from modern human male/neanderthal female.

    Is this the first evidence of alcohol use by modern humans?

  8. #8 John Emerson
    July 31, 2007

    It’s really just a function of exogamy. Any two distinguishable human groups will intermarry some of the time and fight some of the time. When cousins marry cousins, cousins fight cousins.

  9. #9 Sandgroper
    July 31, 2007

    Weeell OK, JE, but Jessica (a fine example herself of the benefits of exogamy) seems to be taking it a bit far here.

    http://upload.wikimedia.org/wikipedia/commons/a/a3/Jessica_Alba.jpg

    Thanks Toto.

  10. #10 Alan Kellogg
    July 31, 2007

    Why is it always Western Europe? Humans and neanderthals didn’t overlap in territory and time in the Near East, and for longer periods? Where are the studies on co-habitatio, hybridization, and introgression in that area for those times?

  11. #11 Sandgroper
    July 31, 2007

    Yes they did – apparently there’s no support for the theory of technology transfer from modern humans to Neanderthals in that case, and it seems that the Neanderthals continued to survive in the area and the modern humans didn’t.

    Maybe it doesn’t make for good newspaper stories.

  12. #12 Sandgroper
    August 1, 2007

    Incidentally, Alan, the evidence for introgression points to a time of around 37,000 years BP, which is a major mismatch for the period of overlap in the Middle East.

    http://www.hhmi.org/news/lahn20061006.html

    “Furthermore, the time of introgression of the D allele into humans — about 37,000 years ago — is when humans and Neanderthals coexisted in many parts of the world.” So not just Western Europe, and not necessarily from Neanderthals, but it is a bit of a worry that much ealier overlap appears not to be noticed in this. But then they weren’t coming at it from that direction, they found the introgression and were looking for a likely source. And it seems that in the case of the much earlier overlap in the Middle East, the anatomically modern humans did not continue to survive in the area, so any possible introgression into modern humans from that time presumably did not survive.

  13. #13 Sandgroper
    August 1, 2007

    …..the earlier period of overlap in the Middle East…..

    Anway, whoever it was, rather them than me:

    http://www.flickr.com/photos/60462668@N00/sets/72057594095796828/detail/

    Warning – do NOT click if you are offended by the sight of naked Neanderthals.

  14. #14 Alec
    August 2, 2007

    The article raises a lot of provocative possibilities. If early modern humans and Neanderthals mated, Neanderthals must have been capable of speech, or else any offspring would have been at a severe disadvantage and unlikely to survive. Also, for any offspring to be viable, early modern humans and Neanderthals must have been … compatible… in terms of intelligence, physical development and other features. Kissing Cousins, in other words.

    Also, on a practical level, if interbreeding occurred, both groups must have appeared sufficiently attractive as to make each other want to get it on.

  15. #15 razib
    August 2, 2007

    both groups must have appeared sufficiently attractive as to make each other want to get it on.

    people fuck sheep. and chickens. and horses.

  16. #16 Alan Kellogg
    August 2, 2007

    Sandgroper on Me,

    And so you see the value of proofreading before you post. I know about the Near East overlap of humans and neanderthals, but sometimes your brain has a mind of its own.

    Now for a bit of contrarianism. Namely, was the introgression thanks to inter-species breeding, or a bacterial or viral infection? :)

  17. #17 Sandgroper
    August 2, 2007

    I’m told that in New Zealand, romantic liaisons with sheep are the norm rather than the exception.

    “How was it for you, darling?”

    “Not baa-aa-aad.”

    Neanderthals capable of speech – now seems to be pretty well established/accepted that they would have been physically capable of complex speech, and would have needed it to engage in the cultural practices evident from some sites (e.g. ritual burials of the dead with burial goods like tools, pigments and other useful stuff for the after-life).

    Compatibility – not that different. Different species of human or sub-species which diverged relatively not too far back, not something non-human. Obviously recognizably human, although different in appearance and culture. Anatomically modern humans then probably didn’t look/smell all that flash either. I know an English male/New Guinea female married couple who look pretty different from each other. Not that I’m suggesting she smells. He does, she doesn’t.

  18. #18 Sandgroper
    August 2, 2007

    Alan – I knew you knew. I was trying to agree with you, but suggest reasons why we don’t see the studies you were asking about. I don’t think it’s just Euro-centrism. That wouldn’t make much sense coming from Lahn, for example.

    Second point – no idea. I have faith that Paabo will get us there, and that Hawksie will explain it all to those of us like me who need it.

  19. #19 Alec
    August 2, 2007

    RE: people fuck sheep. and chickens. and horses.

    Yeah, but we’re not just talking about freaky one night stands. Women are a bit more choosy, so if an early modern woman got it on with a Neanderthal male, he would have to be suitably attractive. Even if breeding occured as a result of a rape, the resulting offspring would have to be acceptable enough not be be killed or abandoned by the woman and her family. If an early modern man got it on with a Neanderthal woman, she would have to be attractive enough and suitable enough to become part of the early human social group, since I do not think that the male would kick her back to her tribe and function as a single father. The woman would also have to be acceptable to other early modern human women and be able to interact with them successfully.

    Neanderthals and speech — The news story implies some uncertainty about the existence of Neanderthal speaking ability, and notes physical differences in the vocal tract that might make Neanderthal speech, if it existed, different from the speech of early modern humans. But again, if interbreeding — and the raising of offspring occurred, the two groups would have to be able to communicate, and the resulting offspring would have to be able to thrive in the early human community.

    It’s not just about the sex. One hard rule of thumb of human history is that when competing groups come into contact, the males will try to kill all the opposing men (and children) and take the women, unless the two groups are roughly equal in power and have to negociate peace, and sometimes an exchange of women.

    What continues to fascinate is how the view of Neanderthals has gone from the first views of a stocky, brutish almost subhuman cave man to that of the guy next door who you would let marry your daughter. But somewhere in between is the question of the degree to which late Neanderthals and early modern humans were compatible enough to be able to successfully interact and to be able for the early modern humans to raise healthy and capable “bi-racial” children.

    As an aside, of course, any early modern humans who joined Neanderthal society ultimately would have died out with them. The same questions about the offspring applies, but the ultimately they would have shared the fate of the Neanderthals.

  20. #20 pconroy
    August 3, 2007

    Alec,

    That’s an interesting point, but supposedly Neanderthal toolkits started to converge on Modern toolkits after they met. So it may be that – just like the spread of farming – cultural exchange was possible. This would mean that the Neanderthals most likely were capable of relating to the Modern’s and learning from them.

    I see the population of Europe by Moderns and the disappearance of Neanderthals as analogous to the English settlers in the New World – their pathogen load killed off many Native Americans, they also killed some of them directly, but likewise they also took some of their women as brides. Today there is virtually no trace of Native Americans in the American North East, but older Anglo-American families from the area must have some Native American genes.

  21. #21 Sandgroper
    August 3, 2007

    At last – the evidence we’ve been looking for.

    http://photos9.flickr.com/14778989_27fc7728a5_o.png

  22. #22 Corporate Serf
    August 3, 2007


    What interested me about the introgression thing is that it seemed to come from modern human male/neanderthal female

    It’s possible there is a selection effect at work here. Given the larger brain / head sizes of neandarthals, and the specific shape of (modern) human pelvis, it may be the opposite introgression will cause death of baby and mother. No c-section then.

    How accurate are the genetic sequences of neandarthals? Aren’t these basically fossilized bones? Wouldn’t the dna degradation be something horrendous?

  23. #23 Sandgroper
    August 4, 2007

    Serf – Paabo reportedly found 1 out of 70 that was suitable,IIRC.

  24. #24 Alec
    August 4, 2007

    RE: I see the population of Europe by Moderns and the disappearance of Neanderthals as analogous to the English settlers in the New World.

    But this assumes that late Neanderthals and early modern humans were very closely related genetically, kinda like a “Quest for Fire” model of hominids. This is an interesting idea, but not necessarily the case. As an aside, again I find it interesting that thinking about Neanderthals has gone from “not like us at all” to “very much like us” even though the available evidence is not conclusive at all. It could also be that Neanderthals and early modern humans were more like tigers and lions.

    And here, Neanderthal/human mating might have been influenced by an expression of Haldane’s Rule. Using lion/tiger mating as an example again, we find an interesting result in the offspring of ligers (the hybrid cross of a male lion and a female tiger). Female ligers are fertile and can reproduce, but male ligers are sterile. As an aside, it is also interesting to note that ligers tend to be significantly larger than either lions or tigers. Might Neanderthal/human hybrids been on average much taller than their parents?

    RE: What interested me about the introgression thing is that it seemed to come from modern human male/neanderthal female.

    The human male/Neanderthal female thing might be related to the shape of the human pelvis and the lack of C-sections, but culture may be involved as well. A Neanderthal female might have been accepted into an early modern human group as a mate or “wife,” and her hybrid offspring would have been accepted as well. But a human female who found herself knocked up by a Neanderthal male might have found herself and her offspring ostracized. Human females who joined Neanderthal society would ultimately have disappeared with their offspring.

    Coming back to lion/tiger mating again, it is also interesting to note that tigons (the hybrid cross of a male tiger with a female lion) manifest similar fertility issues as ligers, that is, male tigons are sterile, while females are generally fertile. The offspring are larger than their parents, but not as large as ligers. Also, a Wikipedia discussion of tigons noted the following in a second generation hybrid, a li-tigon: the animal “spoke” tiger rather than the mix of sounds used by his mother. This raises the issue again as to whether Neanderthals were capable of speech, whether their physical traits influenced the kind of speech that they could produce when compared to humans, and in turn whether human/Neanderthal hybrids could thrive in an early modern human community.

  25. #25 razib
    August 4, 2007

    And here, Neanderthal/human mating might have been influenced by an expression of Haldane’s Rule. Using lion/tiger mating as an example again, we find an interesting result in the offspring of ligers (the hybrid cross of a male lion and a female tiger).

    the separation between lions & tigers is probably at least a multiplicative magnitude (and perhaps an order) greater than between neandertals and sapiens sapiens.

  26. #26 Alec
    August 4, 2007

    RE: the separation between lions & tigers is probably at least a multiplicative magnitude (and perhaps an order) greater than between neandertals and sapiens sapiens.

    This does not in any way mitigate against Haldane’s Rule or other biological considerations being applicable to surmised Neanderthal/human matings. Statements about the separation between neanderthals and sapiens are still more a matter of speculation than informed conclusions based on available data. This is similar to assertions that Neanderthals just died out or were all absorbed by early modern humans — as opposed to being killed off, speculations that are more about what people, including otherwise hard-headed scientists, would like to be true, not what is supported by what we actually know about Neanderthals.

    Also, I continue to find it noteworthy that both professionals in this field and talented amateurs are often remarkably naive about sex. They tend to assume that early hominids were just like Aunt Edna and Uncle Frank in Peoria, plain monogamous monotheists. Thus, they conflate the separate issues of having sex, pregnancy and childbearing, child-rearing, and the acceptance of outsiders into a tribe, without considering non-contemporary and non-Western models.

  27. #27 razib
    August 5, 2007

    Statements about the separation between neanderthals and sapiens are still more a matter of speculation than informed conclusions based on available data.

    no it isn’t.

    1) we have time scales in terms of when hominids settled in europe & northwestern eurasia. we also have time scales for when neandertal-like fossils show up. (less than 1 million years, more on the order of hundreds of thousands of years in the latter case).

    2) we also have some data from mtDNA in terms of coalescence (which pretty much aligns with the fossils from what i recall).

    3) your comment about haldane’s rule speaks directly to time of separation, of course it has to do with how long the lineages were separated. genetic incompatibilities only arise after two lineages have been genetically separated for long enough that divergences can build up that would reduce fecundity. ergo, your analogy to lions and tigers is weak if the two lineages were distinct for far longer than neandertals & modern humans.

  28. #28 razib
    August 5, 2007

    hey tend to assume that early hominids were just like Aunt Edna and Uncle Frank in Peoria, plain monogamous monotheists. Thus, they conflate the separate issues of having sex, pregnancy and childbearing, child-rearing, and the acceptance of outsiders into a tribe, without considering non-contemporary and non-Western models.

    ? this makes no sense since anthropologists have a lively debate about whether pre-modern humans were generally polygynous or monogamous. some of this is rooted in arguments about sexual dimorphism in the various proto-human species.

  29. #29 Levi
    August 5, 2007

    Alec: Women are a bit more choosy, so if an early modern woman got it on with a Neanderthal male, he would have to be suitably attractive.

    If there was widespread interbreeding, wouldn’t the Neandertals also need to be interesting enough to the intellect of the human female? This assumes that if there was widespread interbreeding that to produce a child the couple would have to have sex at least a couple of times over a few days.

    And if so then would this imply some way of communcation between the two groups?

  30. #30 razib
    August 6, 2007

    quantitize ‘widespread.’

  31. #31 Alec
    August 6, 2007

    RE: [Statements about the separation between neanderthals and sapiens are still more a matter of speculation than informed conclusions based on available data.]
    no it isn’t.

    This was sloppiness on my part. What I meant to write was that statements about the significance of the separation between neanderthals and sapiens are still more a matter of speculation than informed conclusions. Neither the fossil record nor the mtDNA offer support for any slam dunk conclusions about the possible interbreeding of Neanderthal and early modern humans. If I read Wolpoff correctly, he suggests that Neanderthal and early modern man were not separate species. Others disagree. If the consensus was that the two groups could easily interbreed, there wouldn’t be much point to arguing the distinction.

    RE: ? this makes no sense [that professionals in this field ... are often remarkably naive about sex ... and ... tend to assume that early hominids were just like Aunt Edna and Uncle Frank in Peoria, plain monogamous monotheists] since anthropologists have a lively debate about whether pre-modern humans were generally polygynous or monogamous. some of this is rooted in arguments about sexual dimorphism in the various proto-human species.

    The debate isn’t very lively at all. I once asked a biologist whether there was any evolutionary basis for fetishism since, for example, there appear to be deep similarities in British and Japanese fondness for bondage even though the societies are very different. I thought his head was going to explode. On another occasion, at a Skeptics Society conference on evolutionary psychology and race at CalTech, another scientist sagely insisted that males naturally seek to mate with females “of their own kind” and seemed honestly oblivious to varieties of human sexual behavior that was not simple pair bonding.

    There are many styles of polygamy and monogamy, but the official discussion of these matters is very unimaginative: no harems, concubines taken in warfare, or kidnapped brides. There is an oddball site that suggests that Neanderthals interbred with early modern humans and brought red hair and autism into the modern human population. The author of this site also suggests that Neanderthals were matriarchal and more likely to engage in group sex, “voluntary cuckoldry,” and female aggressiveness toward female outsiders. I think this stuff is nuttier than an episode of the Art Bell radio show, but at least it is imaginative and attempts to look at a wider range of historical human sexual behavior than is typical.

    The site is here: http://www.rdos.net/eng/asperger.htm

    The bottom line is that while I can easily accept that sex might take place between Neanderthals and early modern humans, questions relating to progeny require a lot more than the evidence currently supports, and there has to be a consideration of possible biological and cultural barriers that might impede easy interbreeding.

    Re: If there was widespread interbreeding, wouldn’t the Neandertals also need to be interesting enough to the intellect of the human female?

    No, don’t think so. If, as some researchers believe, Neanderthals were stronger than early modern man, some pregnancies could have been the result of rape or related to women taken captive after combat and later returned to the human society. Or, Neanderthals and humans might have formed temporary consort relationships, having sex for time and then separating (as orangutans often do). Neanderthal males might have been perceived as extra hunky by early modern human females, the ultimate bad boys. But none of this requires that males and females were admiring each other’s intellect. Again, we don’t know much about the societies of Neanderthals or early modern humans, but there is no reason to assume that mating relationships were typically anything like modern romance, leading to love and marriage and a baby carriage.

    As an aside, if there was regular interbreeding, I would think it mainly arising from Neanderthal females joining early modern human groups, with some contributions from early modern human females becoming pregnant by Neanderthal males. On the other hand, I don’t have much of a problem imagining early modern humans killing Neanderthal/human hybrids and doing everything they could to discourage interbreeding. If there were skin and/or hair color differences, or other easily observable physical differences, it would not be difficult to single out hybrids. This would be an example of a cultural barrier to interbreeding, independent of any biological issues.

  32. #32 razib
    August 6, 2007

    The bottom line is that while I can easily accept that sex might take place between Neanderthals and early modern humans, questions relating to progeny require a lot more than the evidence currently supports, and there has to be a consideration of possible biological and cultural barriers that might impede easy interbreeding.

    i’ve talked about hybridization before. just because two groups are classified as separate species doesn’t mean they can’t hybridize. there is literature about the parameters which might determine the likelihood of sterility of the F1 generation. if you assume that neandertals and proto-moderns were totally isolated from 500,000 years ago to 30 K B.P. it seems likely that crosses would be fertile if they did occur if other mammals are a good judge. since we can’t do a controlled experiment of the situation i’m pretty sure we’ll never totally ‘prove’ whether they ‘did it’ or ‘not.’ but a large number of interbreedings isn’t that important, i’m interested in allelic introgression, not synthesis of two populations.