Autism activist Temple Grandin talks about how her mind works — sharing her ability to “think in pictures,” which helps her solve problems that neurotypical brains might miss. She makes the case that the world needs people on the autism spectrum: visual thinkers, pattern thinkers, verbal thinkers, and all kinds of smart geeky kids.
I recently had a discussion with a student of biology about the implications of the human-Neanderthal interbreeding hypothesis. She suggested that I was putting too much emphasis on the issue of a genetic basis for intelligence, and informed me that a professor in her school made the statement, “From what I’ve read, it seems unlikely that Neaderthals contributed significantly to modern humans.”
Once again, my little BS detector lit up as I realized the game that her instructor was playing with words. “Contribute significantly” is a loaded phrase. There isn’t a 1:1 relationship between the quantity of genetic material transferred and every measure of “significance”. A single gene, for example, could make all the difference in terms of cognitive function, or the ability to use language and speech. These happen to be precisely the kind of contributions being looked at, by the way.
In discussion of the D allele in particular, there is a model of gene transfer in place already which predicts that a gene which confers even slightly higher advantage to its bearer could rise to high frequencies within a population. The D allele just happens to fit that model. Anyway, I haven’t seen any proof that it confers greater “intelligence”, as I also think that word is too ambiguous. The authors of the HHMI study were ambiguous themselves, but they did use a phrase like “more efficient brain function”, which does touch on cognition, but in a non-specific way.
Isn’t it interesting how scientists can use language to be precise and yet, sometimes, they simply refuse to do so?
Even the most orthodox academics admit that something happened in terms of brain chemistry to precipitate the advent of the rise of culture. They also have to admit that it happened in Europe. It turns out that narrative is sometimes the natural enemy of the scientist. Controversy is easy to avoid if you simply focus on the measurements and minutia… all the way up until it isn’t. Until very recently, they have had n layers of uncertainty to rest behind and no pressing need to provide a narrative of how it all happened. Now, they have n-1 layers between them and certainty, and there is a host of complementary data which is going to reduce that number further.
For example, it appears that East Asians and Europeans developed pale skin independently, probably due to local adaptations in response to ultraviolet radiation densities at similar clines. Interestingly, the genes identified in the pigmentation path which correspond to pale skin in Europeans are similar to the same coloration in Neanderthals. Have you seen many ginger Chinese? Probably not. Natural selection models are in competition with sexual selection models for explaining the variations in pigmentation, eye color, and hair form in Europeans, but the evidence is beginning to show that the ultra-pale skin did not make its way into our gene pool until the Holocene.
When you lay out the time line and map, the most parsimonious answer begins to look like an initial wave of Africans meeting up an pairing, perhaps infrequently, with Neanderthals in the Levant. This was followed by some changes in behavior and then an explosion outwards into Europe and western Asia. Here, again, the tan-colored species went on divergent paths, and the group who made it to Europe probably interbred again and more frequently with Neanderthals there. More variation in pigmentation occurred, and the skull measurements of Early Europeans (formerly known as Cro-Magnon) indicate that they were longer – two phenotypical expressions that you would expect to find if the distinct populations were interbreeding.
Now, the Out of Africa view has been dominant, and most academics are smart but not very rebellious. I have recently discovered that the multi-regional hypothesis has actually always been far more accepted in scientific circles than the textbooks and journalists would have you believe, however. I predict that a hard core of politically-inclined researchers (or researchers dependent on money from the politically inclined) will begin to veer into more complex modeling to compensate for the fact that the most parsimonious explanation for the very visible and measurable differences among “populations” today happens to be perhaps the most politically dangerous one.
It’s a great time to be alive.
This interview was conducted prior to the publication of the recent study which concludes that 70% of modern humans are carrying between 1 and 4% Neanderthal genes.
So, this new research proving our kinship with Neanderthals turns out to be rather more complex than I had imagined. It’s not that I am surprised by the complexity of the science, either. I am no expert in paleoarchaeology, paleoanthropology, or evolutionary genetics, and so I knew going into this endeavor that the hard part would be deciphering the science and putting it into common language so that even a layperson, such as myself, might understand it. At least, that’s initially what I thought would be the hard part.
Now I’m not so sure. You see, it turns out that reputations have been staked, research grants have been awarded, and now those damn gene researchers have gone and decoded the Neanderthal genome – thereby threatening to overturn certain well-guarded ideas about race and human origins. Ideas which are both politically expedient and more likely to confer upon their exponents much-needed grant monies. Up until less than one one month ago, the dominant view of scientists of all stripes whose bread and butter is the study of human origins has been that fully modern humans left Africa and replaced the other archaic human lineages that already lived in Europe and western Asia with no gene flow between them. This view is referred to as the Out of Africa theory, and it has just been broken by genetic evidence that supports the upstart Multi-regional Hypothesis. The controversy over words and models of the ebb and flow of genes across the continental divide is, however, really a kind of cover for a much thornier controversy which I will come around to in a moment.
Maybe I’m just being paranoid. We’ll see, I suppose. It’s just that, even today, I was listening to a podcast from the NPR website (click here to read it or listen) from Friday, May 7th, 2010, in which the results of the study were referenced. I love this radio show, but this particular presentation left a bad taste in my mouth and it only supports my growing concern that the public is being glad-handed by academics and policy wonks who would rather play politics than just give us the straight science, unmediated. Let me explain.
The guests whom Ira Flatow brought in to discuss the import of the recent research were Richard “Ed” Green, Assistant Professor of the Biomolecular Engineering Baskin School of Engineering at the University of California, Santa Cruz, and Richard Klein, Professor of Anthropology and Biology at Stanford University in Stanford, California. Both men presumably represent the state of the science in their respective fields of research. Green studies human origins by looking at genes, and Klein studies human origins through analysis of the fossil record. Yet, for all of this combined firepower, the actual import of this research remained entirely untouched, and what is worse, Klein seems to either be not well enough informed to be a part of the conversation or else he flat out lied about the existence certain archaeological finds.
Specifically, although stating he would not be at all surprised to learn that there was some interbreeding going on between anatomically modern humans coming out of Africa with the Neanderthals who were already populating Europe and western Asia, Klein stated in no uncertain terms that there is no archaeological evidence to support this theory. Really? Perhaps Professor Klein missed this find in modern-day Israel, of a cave showing signs of an unbroken succession of human dwelling, and including the remains of both Neanderthals and anatomically modern humans. Okay, that’s probably just a fluke, right? Well, what about this site in Shanidar in Northern Iraq? Alright, alright – so the fossil records does show that Neanderthals and modern humans were lumbering around the same turf at about the same time in the Levant. No big deal, though, there’s no evidence of interbreeding, right? Well, then I’m sure this analysis of what appears to be a the skeletal remains of a human/Neanderthal hybrid child in Portugal is entirely irrelevant.
As I said, either Prof. Klein is reluctant to discuss what the fossil record actually reveals, or else he is unaware of it. Take your pick. Lest you think I am upset with Klein personally, I think it’s far more important to address some of the underlying reasons why this new research makes so many people uncomfortable. This bears directly on the meat of the recent research, which, as I also mentioned, went entirely unexplored during this rather bland discussion on Talk of the Nation Science Friday. After all, wasn’t anyone interested in discussing which pieces of the modern human genome show evidence of having been acquired from Neanderthals? Wouldn’t that be somewhat germane to the discussion? Apparently no one thought so.
The recent research shows that a gene which is crucial to the regulation of brain size, microcephalin, comes in two distinct classes. One class is characterized by the non-D allele, which looks to geneticists like it belongs in the anatomically modern humans and shows a coalescence time similar to other genes in the human genome. The other class of the microcephalin gene contains the D allele, which looks like a genetic oddball that only recently coalesced in our genome at around 37,000 years ago. What is crucially important is that the D allele, which is in all non-Africans, is represented in about 70% of all modern humans whereas the older, “normal” non-D allele is held by the other 30%. Why should that be? The most parsimonious answer is that the introgression of the D allele into modern humans conferred some trait which exerted a positive selection action – meaning that those who have the D allele have enjoyed better reproductive success. In fact, 37,000 years is a remarkably short period of time for that gene to have risen to such a high frequency in the modern human population, and this, my friends IS the interesting thing about the new research. Yet… somehow they never got around to discussing it on air.
The researchers who conducted the original research at the Howard Hughes Medical Institute speculate that the effect of the D allele might be expressed in improved cognitive function for those who possessed it, and this, I believe is one of the reasons why we never heard any discussion of it. Oh, don’t look so surprised. After all, almost two generations of educators and social scientists trying their damnedest to indoctrinate students in Social Construction theory, despite the efforts of evolutionary psychologists and geneticists whose work continues to undermine that theory.
The Social Construction theory is essentially this: that any differences in outcomes between individuals in education and in life are based upon environment and opportunity, and that their respective genetic legacy plays no role. While this no doubt comes from a very well-intentioned place, it is entirely wrong-headed in terms of policy and in science funding, and in this last point we might have an indication of why both academics and scientists are so loathe to break with tradition even though the science is making it more difficult every day. It is not hard to imagine that any research that undermines Social Construction theory might face more difficulty in terms of getting funding from both private foundations as well as government policy makers. Who, after all, wants to be associated with research that might make them vulnerable to denunciation as racist? Besides, the current batch of scientists take great pains to remind us that race does not even exist. That’s right. There are actually serious proposals to remove any reference to race in scientific jargon and replace it with words like “population”. Why? The rationale is based on research that states that genetic difference between so-called races is lower than genetic variation found within any given race. No one mentions that the same thing might be said of different dog breeds, because it is obvious to anyone who knows dogs that there are not only morphological differences between breeds, but also differences in temperament and aptitudes. Of course there are genetic differences between self-labeled races, and if you don’t believe it then take a look at how pharmaceutical companies would like to tailor fit their medications to them. But the fact that there are genetic differences between people is a given, and everyone knows it, and this isn’t really the important thing.
The important thing is that what we have is a situation wherein political expediency and fear itself is driving science underground, and I do not have any reason to believe that this trend will end any time soon. Galileo was accused of heresy when he took up the Copernican view that the Earth is not the center of the universe and that the Earth moves around the sun. His unmitigated gall landed him in hot water with the Holy Inquisition and his work was considered “false and contrary to Scripture”. He actually offered up his telescope to the Bishops who condemned him, and their response? They simply refused to look through his instrument and then they condemned it as a tool of the Devil. Genetic research today is facing the same kind of hysterical response from self-styled defenders of the public good whose own presuppositions about the ultimate meaning and implications of such research say more about their own beliefs than they do about the dangers of a science allowed to tell the truth. Today’s Inquisition is academic orthodoxy, and anyone who believes that politics plays no role in shaping science is, at best, completely ignorant of the state of things.
Don’t take my word for it, however. Bruce Lahn headed up the team from the Howard Hughes Medical Institute whose research into the gene microcephalin was the locus of the most recent research. He has abandoned this entire line of research altogether now because “It’s getting too controversial.”
Spencer Wells, head of the National Geographic Society’s Genographic Project says that they may try to find the genetic basis for things such as differences in height between Danes and pygmies, but says that they will not study the brain. “You have to follow the data wherever it leads, but speculating in this field is dangerous,” says Wells.
And then there is Eric Lander, chief of the Broad Institute, a genetics research center in Cambridge, Massachusetts, who says that the risk isn’t so much in finding a genetic difference between races, but in “saying there is a story to fit it.”
This is the most frustrating part of this whole scene for me. When I look at the Neanderthal genomic research and consider what it says to us, I see a lesson in appreciation for what happens when humans of “dissimilar stock” make babies who are both beautiful and perhaps fitter than either of their parents. I see evidence that shatters centuries of noxious ideas regarding racial purity. I see the potential for us to provide a solid scientific rationale for embracing cognitive differences rather than trying to beat everyone down through pharmaceuticals to match some normative mean which, quite frankly, does not exist. Yes, I see a threat to orthodoxy in terms of mental health, education, social justice, and other issues, but apparently the issue of genetic disposition and human differences is too hot for the gatekeepers of science and journalism to endure. The only way to get to the other side of this, to a place where we can actually use the science to make the world a better place, is by following the science and being mature enough to deal with what the science tells us. As it stands, I am afraid that, as in too many other ways in modern life, we are led by the fearful and by scientists who may be good at science but who are not so good at standing up in the face of political backlash.
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