Neandertals are our ancestors

[SoonerCoug]

This is an interesting question too. I thought I had read that the idea of interbreeding had been out there for a long time. Is this just the first actual evidence of it?

This is not my area, but I don't think this is the first evidence of it, although it might be the most direct evidence.

It's my understanding that previous evidence consists of skeletons that have intermediate features (sort of a blend of neanderthal and modern human features).

[creekster]

This is not my area, but I don't think this is the first evidence of it, although it might be the most direct evidence.

It's my understanding that previous evidence consists of skeletons that have intermediate features (sort of a blend of neanderthal and modern human features).

I think this is one of the first studies to offer direct genetic evidence of the interbreeding. It appears, based on my cursory review of the linked article, that this study analyzed the recently sequenced Neandertal genome and concluded that 1-4% of genes in non-african populations are of neandertal origin. We have met the thick-limbed, heavy-browed enemy, and he is us.

[woot]

Regarding racial stuff, it is a pretty big third rail, so a lot of people just don't want to touch it. I think the bigger issue, however, is that until there is really good evidence for greater or lesser intelligence in certain populations, there's just no reason to speculate. But it is true that scientifically, it's possible that such intelligence differences do exist, although they would have to be very slight due to the short timeframe during which any such change could have occurred. As far as debunking The Bell Curve, I prefer Gould's "Mismeasure of Man" to GG&S. Either will do, though. TBC is a mess.

So yeah, the findings at hand show that "Homo neanderthalensis" is no more, and "Homo sapiens neandertalensis" should now be the proper name for neandertals. I've long thought it was naive to think there was no interbreeding, and even if there weren't any interbreeding, 400,000 years isn't long enough for speciation to have occurred, so I've always thought of them as a subspecies.

The idea that Homo sapiens evolved not from a single African population in the relatively recent past, but rather evolved simultaneously in multiple regions of the earth, has been around for a long time. Franz Weidenreich originally proposed it, but it was since altered by Milford Wolpoff and Alan Thorne to include a large amount of gene flow between populations, commensurate with the very low genetic diversity in humans compared to just about any other animal.

The neandertal genome doesn't necessarily support this view, but it does pretty much demolish the strict out-of-africa hypothesis that seemed to me very unlikely but which has been the dominant view for the last couple decades.

Evidence for multiregionalism to this point has been largely based on morphological characteristics. For instance, researchers noticed a long time ago that modern Europeans have much more robust facial features than any other modern humans, similar to neandertals; in Asia, individuals found from several hundred thousand years ago already had a more sloping forehead and shovel-shaped incisors that modern Asian populations still have, suggesting that the earlier individuals weren't replaced by Africans, but rather interbred with them.

DNA confirmation in that scenario will be tougher. The findings based on the neandertal genome will probably open a lot of people's minds to this possibility, however.

[creekster]

Regarding racial stuff, it is a pretty big third rail, so a lot of people just don't want to touch it. I think the bigger issue, however, is that until there is really good evidence for greater or lesser intelligence in certain populations, there's just no reason to speculate. But it is true that scientifically, it's possible that such intelligence differences do exist, although they would have to be very slight due to the short timeframe during which any such change could have occurred. As far as debunking The Bell Curve, I prefer Gould's "Mismeasure of Man" to GG&S. Either will do, though. TBC is a mess.

Are you taking the position that there is simply a lack of evidence on this issue?

[woot]

Are you taking the position that there is simply a lack of evidence on this issue?

I haven't seen any unequivocal evidence showing that one race is smarter than another, no. I haven't looked into it lately, so maybe something has come out since. Part of this debate would be defining what the hell "race" even means in a biological context. There are some useful working definitions, but none that hold up when applied across all humans. Another part would be finding a way to measure intelligence in a way that isn't so heavily influenced by culture, or in establishing what it means to have more or less intelligence, to establish that there's only one kind of intelligence, etc.

[creekster]

I haven't seen any unequivocal evidence showing that one race is smarter than another, no. I haven't looked into it lately, so maybe something has come out since. Part of this debate would be defining what the hell "race" even means in a biological context. There are some useful working definitions, but none that hold up when applied across all humans. Another part would be finding a way to measure intelligence in a way that isn't so heavily influenced by culture, or in establishing what it means to have more or less intelligence, to establish that there's only one kind of intelligence, etc.

Exactly. Isn't the second half of your post really the point? There is no meaningful way to define the difference, and hence no disticntion to be meaningfully drawn. And are you really asserting here that perhaps some unequivocal evidence showing one 'race' was smarter than another may have slipped into the public domain and no one really noticed? Come on. I suspect you really don't want to toss me a bone but seriously?

[woot]

Exactly. Isn't the second half of your post really the point? There is no meaningful way to define the difference, and hence no disticntion to be meaningfully drawn. And are you really asserting here that perhaps some unequivocal evidence showing one 'race' was smarter than another may have slipped into the public domain and no one really noticed? Come on. I suspect you really don't want to toss me a bone but seriously?

Well, if something did come out, it wouldn't surprise me if the researchers slow-played it and let someone else make the conclusions. But yeah, I was mostly covering my ass, as this really isn't something I study.

[myboynoah]

That humans and neanderthals mated was covered in great detail in those Clan of the Cave Bear books.

[BigFatMeanie]

I'm confused on how can we share 95+% of our DNA with chimpanzees, who aren't in the same genus or subtribe, but only 1-4% of our DNA with neandertals who are in the same genus?

Can someone enlighten me on how this classification system works?

[woot]

I'm confused on how can we share 95+% of our DNA with chimpanzees, who aren't in the same genus or subtribe, but only 1-4% of our DNA with neandertals who are in the same genus?

Can someone enlighten me on how this classification system works?

Good question. My wording in the OP was somewhat rough, so forgive the confusion. Humans do indeed share something like 98.8% of our DNA (depending on the level under consideration) with chimps. The figure of at least 1-4% refers to the amount of the modern non-African genome that seems to have been inherited from neandertals, as opposed to non-neandertal upper paleolithic folks. This is largely figured out by looking at the areas in the genome that vary within humans and comparing them to the same loci in the neandertal genome. So, while our similarity to chimps can't be denied, we inherited that similarity through at least a couple different lines of recent ancestry.

[Ma'ake]

The neandertal genome doesn't necessarily support this view, but it does pretty much demolish the strict out-of-africa hypothesis that seemed to me very unlikely but which has been the dominant view for the last couple decades.

Evidence for multiregionalism to this point has been largely based on morphological characteristics. For instance, researchers noticed a long time ago that modern Europeans have much more robust facial features than any other modern humans, similar to neandertals; in Asia, individuals found from several hundred thousand years ago already had a more sloping forehead and shovel-shaped incisors that modern Asian populations still have, suggesting that the earlier individuals weren't replaced by Africans, but rather interbred with them.

DNA confirmation in that scenario will be tougher. The findings based on the neandertal genome will probably open a lot of people's minds to this possibility, however.

Interesting. I read the Neanderthal research to (potentially) support the out-of-Africa theory, as interbreeding with Neanderthals would have occurred in southern Europe (ie, after a migration from Africa) with the tell-tale DNA tagging along as migrations spread from there. This is why the western & southern Africans don't have the DNA... they were left behind, everyone else inherited & carried the DNA in the human dispersion.

[SoonerCoug]

Interesting. I read the Neanderthal research to (potentially) support the out-of-Africa theory, as interbreeding with Neanderthals would have occurred in southern Europe (ie, after a migration from Africa) with the tell-tale DNA tagging along as migrations spread from there. This is why the western & southern Africans don't have the DNA... they were left behind, everyone else inherited & carried the DNA in the human dispersion.

Great to see you here, Ma'ake!

[Ma'ake]

Great to see you here, Ma'ake!

Thanks Sooner!

[SeattleUte]

This is interesting. So let me axe you something it makes me think of.

A law student at Harvard has been getting crucified on the internet because she has suggested that it doesn't make sense that races have evolved pretty varied traits but the assumption seems to be that they all evolved identical intelligence. I think this was her lame way of explaining why so many African governments are in disarray.

I have said in the past I don't think it is a vary useful inquiry and that there is the potential for lots of harm. And I do believe that. So with all that said, is this something that has been seriously studied? Is it too much of a third rail? Just curious as to the state of the science itself. I figured you would know.

I can immediately think of a number of reasons why the Harvard Law student's question is absurd and she deserves to be crucified.

First, the "races" haven't "evolved pretty varied traits." That false predicate is the first reason the very question you ask is absurd. In the first place, race is essentially a social construct. From "race" to "race" you see the ability to procreate between races, use of language (a uniquely human thing), the ability to master written language, and pretty much the same appearance. Race is literally only skin deep. It's not just a PC saying. The "differences", such as tendency to grow facial hair, texture of the hair, skin color, etc. are trivial to the nth degree in comparison to the like traits.

Also, the question is absurd because of the complexity and infinite variety of and near impossibility even of defining human "intelligence" in any authoritative way. Part of this is the indubitable fact that every permutation of human intelligence you can think of is found in any race. This is the lesson of Guns Germs and Steel (which is not a study but a very enlightening popular science and history book). An Australian bushman would easily survive in an environment that would inevitably kill you or me in a few days at least. Most successful business people I have known (I have known many) are not "intellectuals". I have known people who earned hundreds of millions of dollars in their lifetimes who scored low on standardized tests and don't read books. These people are stupid by most academic measures, but are geniuses by the almighty dollar scoreboard. It's not hard to see why the bushman is smart in his way and we may be smarter in our own way, and it has everything to do with environment in the relatively immediate human history.

It's also an absurd question if you have even a rudimentary understanding of human evaluation. We are all part of the same evolutionary tree, and part of the same succeeding branch clear out to the smallest end twig on the human tree. There is no logical reason why blacks or native Americans for example shouldn't be able to reach equivalent intellectual heights as whites, since we are the self-same species (as indeed many in fact have). One of the great evils of myths concerning the origin of skin colors is that beyond racism you completely obscure any enlightened view of how humans came to be. What a tragedy to not appreciate the uplifting truth painstakingly laid out in Guns Germs and Steel about how American aborigines came to be what they were when Europeans found them, because you believe they were cursed by God with brown skin, etc.

Finally, another false predicate of the question is that scientists have never looked at the issue or been motivated to. The Nazis, for example, did at length, resorting to all kinds of approaches including measuring brain size and shape between the races, etc. It was all gobbledygook, and not for want of trying to come up with something elegant and insightful about the races.

[UtahDan]

It's not hard to see why the bushman is smart in his way and we may be smarter in our own way, and it has everything to do with environment in the relatively immediate human history.

So you think that the bushman is smarter than we are in the same sense that a kangaroo is and that our respective environments have selected for this in "relatively immediate human history?" Every one else so far has said that the question of whether their are differences in cognitive adaptations between races is closed and that there are none. And here you are saying that the question is closed and that there clearly differences explained by environment in the "relative immediate human history." I don't think creekster is going to like that.