Are there human races?

UPDATE:  I’ve received an email from a researcher who points out that two of my statements are either misleading or incorrect in view of more recent work. Here’s the email and links:

In your interesting blog article “Are there human races?”, you write:”As has been known for a while, DNA and other genetic analyses have shown that most of the variation in the human species occurs within a given human ethnic group, and only a small fraction between different races. That means that on average, there is more genetic difference between individuals within a race than there is between races themselves.”– But this is patently false. I Tal (2012b) I show that pariwise genetic distances, from within- and between-populations, are substantially divergent (in fact, for Fst=0.15, reflecting average intercontinental differentiation from SNPs, the averages differ by almost 50%).

Also, you ask:”I’m not aware that anybody has tested the accuracy of diagnosing a single indvidual’s geographic origin from her multilocus genotype; if such studies exist, please let me know.”– Yes. In Tal (2012a) I develop models that show that classification accuracy approaches 100% even for very close populations, given enough loci. I then analyze recent empirical studies of human populations under this framework.

Tal O, 2012a. The Cumulative Effect of Genetic Markers on Classification Performance: Insights from Simple Models. Journal of Theoretical Biology. Volume 293, 21 January, Pages 206-218.

Tal O, 2012b. Two Complementary Perspectives on Inter-Individual Genetic Distance. In Press, BioSystems.

__________________________

 

One of the touchiest subjects in human evolutionary biology—or human biology in general—is the question of whether there are human races.  Back in the bad old days, it was taken for granted that the answer was not only “yes,” but that there was a ranking of races (invariably done by white biologists), with Caucasians on top, Asians a bit lower, and blacks invariably on the bottom.  The sad history of biologically based racism has been documented in many places, including Steve Gould’s book The Mismeasure of Man (yes, I know it’s flawed).

But from that sordid scientific past has come a backlash: the subject of human races, or even the idea that they exist, has become taboo.  And this despite the palpable morphological differences between human groups—differences that must be based on genetic differences and would, if seen in other species, lead to their classification as either races or subspecies (the terms are pretty interchangeable in biology). Racial delimitation could, critics say, lead to a resurgence of racism, racial profiling, or even eugenics.

So do races exist?  The answer of Jan Sapp, a biology professor at York University in Toronto, is a firm “no”, as given in his new American Scientist piece “Race finished,” a review of two new books on human races (Race?: Debunking a Scientific Myth by Ian Tattersall and Rob DeSalle and Race and the Genetic Revolution: Science, Myth, and Culture, edited by Sheldon Krimsky and Kathleen Sloan).  As Sapp notes, and supports his conclusion throughout the review:

Although biologists and cultural anthropologists long supposed that human races—genetically distinct populations within the same species—have a true existence in nature, many social scientists and geneticists maintain today that there simply is no valid biological basis for the concept. The consensus among Western researchers today is that human races are sociocultural constructs.

Well, if that’s the consensus, I am an outlier.  I do think that human races exist in the sense that biologists apply the term to animals, though I don’t think the genetic differences between those races are profound, nor do I think there is a finite and easily delimitable number of human races.  Let me give my view as responses to a series of questions.  I discuss much of this in chapter 8 of WEIT.

What are races?

In my own field of evolutionary biology, races of animals (also called “subspecies” or “ecotypes”) are morphologically distinguishable populations that live in allopatry (i.e. are geographically separated).  There is no firm criterion on how much morphological difference it takes to delimit a race.  Races of mice, for example, are described solely on the basis of difference in coat color, which could involve only one or two genes.

Under that criterion, are there human races?

Yes.  As we all know, there are morphologically different groups of people who live in different areas, though those differences are blurring due to recent innovations in transportation that have led to more admixture between human groups.

How many human races are there?

That’s pretty much unanswerable, because human variation is nested in groups, for their ancestry, which is based on evolutionary differences, is nested in groups.  So, for example, one could delimit “Caucasians” as a race, but within that group there are genetically different and morphologically different subgroups, including Finns, southern Europeans, Bedouins, and the like.  The number of human races delimited by biologists has ranged from three to over thirty.

How different are the races genetically?

Not very different.  As has been known for a while, DNA and other genetic analyses have shown that most of the variation in the human species occurs within a given human ethnic group, and only a small fraction between different races. That means that on average, there is more genetic difference between individuals within a race than there is between races themselves. Nevertheless, there are some genes (including the genes for morphological differences such as body shape, facial features, skin pigmentation, hair texture, and the like) that have not yet been subject to DNA sequencing, and if one looked only at those genes, one would obviously find more genetic differences. But since the delimitation of races has historically depended not on the  degree of underlying genetic differences but only on the existence of some genetic difference that causes morphological difference, the genetic similarity of races does not mean that they don’t exist.

Further, one wouldn’t expect human “races” or ethnic groups to show substantial genetic differences—there hasn’t been enough time for those differences to accumulate given that most human groups arose since our migration out of Africa between 60,000 and 100,000 years ago.

Nevertheless, even if most human variation occurs within rather than between races, there are statistical differences between human groups that can, when combined, be used to delimit them.  Here’s a figure from the paper by Noah Rosenberg et al. (reference at the bottom) that uses these “multilocus” genotypes to distinguish human populations. Their study involved 1056 individuals studied from 52 geographic populations.  The genetic analysis was comprehensive, involving 377 autosomal microsatellite loci (“autosomal loci” means “genes not on the two sex chromosomes”).

Rosenberg et al. fed the genetic data into a clustering algorithm that sorts individuals into a pre-specified number of groups, K (they used Ks between 2 and 6).  I show below the data from predetermined clusters numbering 4,5, and 6.  That algorithm sorts out populations into pretty distinctive genetic groups (remember, this involves combining data from many genes): either 5 or 6.  At a sorting algorithm involving 5 groups, the authors note that the genetic clusters “corresponded largely to major geographic regions.” Those regions are roughly sub-Saharan Africa, Europe and the Middle East, Eastern Asia, Melanesia and Oceania, and the America. At K = 6, we get another group, the Kailash of northern Pakistan.

(Click to enlarge):


Of course, each of these groups can be more finely subdivided in terms of population structure: here are clustering algorithms used in determining substructure in America and the Middle East:

This shows the difficulty of answering the question of “how many races are there?” One could call Eurasians a race, or one could call Bedouins a race. It all depends on how finely you want to divide things up, and this is precisely what is expected if populations have evolutionary ancestry, which produces clusters of groups nested within each other.  What is clear, though, is that human populations are genetically different, and can be diagnosed as genetically different using multiple pieces of DNA.  Thus, although you may not be able to determine the geographic origin of a single person simply by looking at her morphology, you may be able to do that pretty accurately by combining information from lots of genes. I’m not aware that anybody has tested the accuracy of diagnosing a single indvidual’s geographic origin from her multilocus genotype; if such studies exist, please let me know.

Why do these differences exist?

The short answer is, of course, evolution.  The groups exist because human populations have an evolutionary history, and, like different species themselves, that ancestry leads to clustering and branching, though humans have a lot of genetic interchange between the branches!

But what evolutionary forces caused the differentiation?  It’s undoubtedly a combination of natural selection (especially for the morphological traits) and genetic drift, which will both lead to the accumulation of genetic differences between isolated populations.  What I want to emphasize is that even for the morphological differences between human “races,” we have virtually no understanding of how evolution produced them.  It’s pretty likely that skin pigmentation resulted from natural selection operating differently in different places, but even there we’re not sure why (the classic story involved selection for protection against melanoma-inducing sunlight in lower latitudes, and selection for lighter pigmentation at higher latitudes to allow production of vitamin D in the skin; but this has been called into question by some workers).

As for things like differences in hair texture, eye shape, and nose shape, we have no idea.  Genetic drift is one explanation, but I suspect, given the profound differences between regions, that some form of selection is involved.  In WEIT I float the idea that sexual selection may be responsible: mate preferences for certain appearances differed among regions, leading to all those physical differences that distinguish groups.  But we have no evidence for this.  The advantage of this hypothesis is that sexual selection operates quickly, and could have differentiated populations in only 50,000 years or so, and it also operates largely on external appearance, explaining why the genes for morphology show much more differentiation among populations than random samples of microsatellite genes, whose function we don’t know.

What are the implications of these differences?

Not much.  There are some medical implications.  As is well known to doctors, different populations have different frequencies of ailments.  Some of that could, of course, be due to cultural rather than genetic differences, but some is undoubtedly genetic, and that should be taken into account when diagnosing an individual.  Sickle-cell anemia, for example, is much more prevalent among sub-Saharan Africans and their descendants (e.g., American blacks brought over as slaves) than among Eurasians.  Ashkenazi Jews, too, have their own unique spectrum of genetic diseases.

Everyone wants to know, of course, if different races differ genetically in their abilities, especially intelligence.  While I think there may be statistical differences among races in these things, it’s not as obvious that sexual (or natural) selection would operate as strongly on genes involving these traits as on superficial external characteristics.  We just don’t know, and in the complete absence of data it is invidious to speculate on these things.  It’s just as scientifically unsupported to say, for example, that there is no difference among populations in mathematical ability as it is to say that there are differences.  In the absence of data, we must follow the apophatic theologians and remain silent.   And, at any rate, any such differences cannot be used to justify racism given the tremendous variation we see in other genes between members of different populations.

One can argue whether it’s even justifiable to scientifically study things like differences in IQ between populations given the political ramifications of finding differences.  I go back and forth on this, but tend to think that it’s more interesting scientifically to study the differences that we know exist—in things like eye shape and skin pigmentation—and try to figure out why evolution promoted those differences.

I haven’t talked much about Sapp’s review, as I find it tendentious; nor have I read the books he’s reviewing.  Perhaps I’ll change my mind about race after reading them, but based on what I know about human population differentiation, for now I think that “races” are biologically real (though we can’t delimit them precisely), and are certainly not “sociocultural constructs.” The “sociological constructs” thing is simply political correctness imposed on biological reality. In view of the morphological and genetic differences among human populations, how can such differences be “constructs”?

____________

Rosenberg, N. A., J. K. Pritchard, J. L. Weber, H. M. Cann, K. K. Kidd, L. A. Zhivotovsky, and M. W. Feldman. 2002. Genetic structure of human populations. Science 298:2381-2385.

193 Comments

  1. GBJames
    Posted February 28, 2012 at 6:39 am | Permalink

    subscribe

  2. Ray Moscow
    Posted February 28, 2012 at 6:53 am | Permalink

    Yes, I’m subscribing, too.

    Much of the problem with ‘race’ is that the concept was widely used — and still is used — to oppress the rights of many people.

    What are the implications of these differences?
    Not much.

    That’s what I think, too.

    • Frank
      Posted February 28, 2012 at 9:11 am | Permalink

      I think there is a bigger problem, and I don’t think Jerry makes a good argument for the utility of the race concept. Of course, there is genetic variation among indigenous peoples around the world, and some of this variation involves obvious phenotypic traits, like degree of melanism. Howver, for race to be meaningful, there should be DISCRETE variation among a relatively small number of groups, and the defining characters can’t be arbitrary. It has long been known that the number of subspecies or races in a particular vertebrate depends on which characters are arbitrarily chosen. The fact that human global genetic and phenotypic variation can be parsed into 3 to 30 races tells you that the concept of race is biologically meaningless. I defy anyone to travel from Lappland to India and tell me exactly where the “white” or “Caucasian” race ends. Medicine should continue to probe genetic differences among different peoples, but terms like white, African, Asian races are downright misleading.

      • Alex Ling
        Posted February 28, 2012 at 9:49 am | Permalink

        No one claims that races, either in humans or other animals, must be clear divisions. The best way to illustrate is by pointing out the problems with defining species– there are tons of species concepts. However, the fact that there is no clear concept doesn’t invalidate the idea of races and species.

        Moreover, the idea of human races has utility in science as well as society. For the former, genetic studies such as genome-wide association studies acquire data that needs to be controlled for by race. For the latter, the simple fact that we still use racial concepts means that it has utility. No one, for instance, talks about darker-pigmented-individuals-of-African-extraction-with-significant-admixture-with-ligher-pigmented-inviduals-of-European-extraction civil rights movement.

        • Frank
          Posted February 28, 2012 at 1:20 pm | Permalink

          We often “use” categories that are artificial and arbitrary – that criterion does not make those categories definable in a discrete objective way. I think Jerry would argue with you that species are arbitrarily defined, or that all species concepts are equally real. As for your last sentence, the fact that we call folks with a minority of their genes from Africans African-Americans proves my point that the common use is biologically meaningless and misleading. Many “African Americans” derive a majority of their genes from non-Africans – the designation is cultural, not biological.

          • Kharamatha
            Posted February 29, 2012 at 2:29 am | Permalink

            “Many “African Americans” derive a majority of their genes from non-Africans – the designation is cultural, not biological.”

            Good point.

            • Posted February 29, 2012 at 2:42 am | Permalink

              My first wife was half English and half Ghanaian. She used to be puzzled by Americans calling themselves black or “African American” and would say “But they’re whiter than me.” Incidentally, in Ghana people would say she was white.

      • Thanny
        Posted February 28, 2012 at 10:00 am | Permalink

        I challenge you to walk the color palette and tell me where red ends and orange begins.

        Clearly such notions as “red” and “orange” are meaningless.

        • truthspeaker
          Posted February 28, 2012 at 11:21 am | Permalink

          +1

        • NewEnglandBob
          Posted February 28, 2012 at 1:09 pm | Permalink

          Is “walking the color palette” akin to “tripping the light, fantastic”?

        • Frank
          Posted February 28, 2012 at 1:24 pm | Permalink

          You make my point for me. Breaking up the electromagnetic spectrum into discrete categories for human-visible light is arbitrary, and there is indeed “red-orange”. We can still use “red” and “orange” in a practical way, just as we can use “dark” and “light” skin, but that does NOT make them objective, discrete categories. I never said the phrase “dark” or “light” skin is meaningless, I said that discrete, objectively defined races (based on continuous variation in skin color, say) are BIOLOGICALLY meaningless. Same with the color palette.

          • Posted February 29, 2012 at 6:16 pm | Permalink

            The review by Jan Sapp is PC run wild and doesnt deserve further comment. About red and orange, you are missing the point. They are NOT separated, discrete entities and neither are races (and Jerry said so) but they are still useful terms and we generally know what they mean. Race has been muddled by the “social construction of race” but does have a useful meaning in biology (and maybe in sociology, but previous errors will have to be dealt with). But given that the social construction IS so muddled, and the politics around it (particularly in the Eurocentric world we live in) so extreme (not just from teh racists, but equally or even more muddled from the anti-racists) that one can definitely argue in favor of dropping the term and using “population” or “ethnicity” instead.
            But to say it is “meaningless” in principle is rather ignorant.

            • Ali Minai
              Posted March 6, 2012 at 1:30 pm | Permalink

              Omar, you are right, but once we replace the word “race” with something neutral, most of the motivation for trying to do differential analysis will also disappear. The study of human subspecies is interesting mainly to the extent it addresses the sociocultural construct of “race”. Without that, the debate will mainly be of interest to evolutionary biologists and geneticists. That doesn’t make it irrelevant, and arguably increases its rigor, but it won’t be the subject of popular books like the ones Sapp reviews.

    • Mike Pearlstein
      Posted March 1, 2012 at 8:35 pm | Permalink

      ***— and still is used — to oppress the rights of many people. ***

      Are you referring to the discrimination against East Asians in college admissions?

      ***What are the implications of these differences?***

      Linda Gottfredson has written about this. Basically, if you look at psychometric results they imply that some groups will be overrepresented in some areas, others less so.

  3. J
    Posted February 28, 2012 at 6:54 am | Permalink

    Heh, I was reading about this in WEIT only this morning! I think you handle what is undoubtedly a delicate matter very well – it would be silly to deny that there are differences & even sillier to treat people differently because of them, but it leads to a fascinating discussion of the manifestations of evolution within our own species (even if data on selection pressures is lacking).

  4. Posted February 28, 2012 at 6:57 am | Permalink

    I’m with you here, Jerry. As I started reading this, I was thinking of the results of Rosenberg et al. (or something similar that I’d seen).

    I think it is important to acknowledge that there are significant differences in different human populations, whether you call them races (which is clearly politically loaded), subspecies (which could be taken as a slur, if “sub” is misunderstood!) or ecotypes (probably the best term to use, then — it sounds, um, clinical), for at least medical reasons (as you note). One instance of difference (by gender as well as ecotype) that I’ve come across professionally is that Asian women tend to have poorly defined Galton ridge patterns which means that they have (more!) difficulty using some kinds of biometric fingerprint sensors.

    /@

    • Posted February 28, 2012 at 7:08 am | Permalink

      Further thoughts:

      • The editors of the New Oxford American Dictionary seem clued in (under “race”): “Scientifically it is accepted as obvious that there are subdivisions of the human species, but it is also clear that genetic variation between individuals of the same race can be as great as that between members of different races.”

      • Isn’t the existence of “race” implicit in declarations of human rights and anti-racist legislation? If expert witnesses can be called to testify “race” doesn’t exist, what would lawyers make of statements like “discrimination on the basis of race”?

      • It seems to be more widely accepted that “ethnic groups” actually exist. (Please rebut.) Is there any recognised ethnic group that spans non-contiguous races? Or are all such groups “social clades within biological clades”?

      /@

      • Posted February 28, 2012 at 7:34 am | Permalink

        That phrase about variation in the dictionary definition you quote relies on the same math error I mentioned above.

        • Posted February 28, 2012 at 7:35 am | Permalink

          Oops, “below”, not “above” (Comment 8)

        • Posted February 28, 2012 at 7:58 am | Permalink

          Oh, well: I was trusting Jerry’s “[t]hat means that on average, there is more genetic difference between individuals within a race than there is between races themselves” to be correct… :-/

          /@

          • Posted February 28, 2012 at 9:01 am | Permalink

            Ant, Jerry’s statement is literally correct. His CONCLUSION from that statement is incorrect. His statement does not really imply that genetic differences between races are small. His statement would be true at high-diversity loci even if he was talking about groups that consisted of completely different species (no shared genes at all)!

            • Posted February 28, 2012 at 10:52 am | Permalink

              OK… I’m being unusually (?) dense here… why is Jerry right, but NOAD wrong?

              /@

              • Posted February 28, 2012 at 11:20 am | Permalink

                Ant, you are right, the NOAD definition is literally almost correct (though there is a subtle difference between what NOAD says and what Jerry says). I am complaining about the “but” in the NOAD definition. They say it is accepted as obvious that there are subdivisions, BUT….and then they give a statement about variation, as if this should shed doubt on the reality of subdivisions. This is also the way Jerry argued. Statements like Jerry’s about variation do not imply that subdivisions are weak. Jerry’s statement about variation would be true even the groups shared no alleles.

              • Posted February 28, 2012 at 11:22 am | Permalink

                My last sentence should read “Jerry’s statement about variation COULD be true even IF the groups shared no alleles …”

              • Posted February 28, 2012 at 12:48 pm | Permalink

                Got it. (I think.) Thanks for your patience!

                /@

      • Moochava
        Posted February 28, 2012 at 7:51 am | Permalink

        “• Isn’t the existence of “race” implicit in declarations of human rights and anti-racist legislation? If expert witnesses can be called to testify “race” doesn’t exist, what would lawyers make of statements like “discrimination on the basis of race”?”

        This only assumes that race has a sociological reality, not a biological one. There are many examples of racism that don’t depend on genetics, like the English and English-descended Americans despising the Irish. Even in ethnically homogenous areas, “racism”-like behavior appears, such as with the baffling case of the Cagots in France: http://en.wikipedia.org/wiki/Cagot

        • Posted February 28, 2012 at 8:00 am | Permalink

          But animosity between English and Irish would be ethnic bigotry, or competing nationalisms, not racism. Not all group-based bigotry or antagonism is racism; if it were, we wouldn’t need the word racism.

          • Dan L.
            Posted February 28, 2012 at 11:19 am | Permalink

            That’s how it seems now but that’s an ahistorical perspective. In the real world of the 19th century, I can assure you the Dutch- and English-derived peoples of the United States saw the Irish and Italian immigrants as entirely different races from themselves and from each other.

            • truthspeaker
              Posted February 28, 2012 at 11:22 am | Permalink

              That’s my understanding too.

        • Posted February 28, 2012 at 8:01 am | Permalink

          Fair point. But where in law is race defined in a sociological sense in preference to a biological sense?

          /@

          • Moochava
            Posted February 28, 2012 at 8:04 am | Permalink

            How should I know? I’m a pedant, not a lawyer.

  5. Lsuoma
    Posted February 28, 2012 at 6:57 am | Permalink

    /sub

  6. Knuckle Pushups
    Posted February 28, 2012 at 6:57 am | Permalink

    Humans are very different and very alike. The danger I see is of letting the arrogance and sanctimony of politics, political correctness and multiculturalism dictate to scientists what they can and cannot study and or say, write, discuss or teach. The danger is not the possibility of some type of future racism, the danger is of squelching whatever the truth is, palatable or not.

    • Posted March 2, 2012 at 5:54 pm | Permalink

      So, in other words, those of us who don’t belong to the club should just shut up and know our place. Racism in science? Biased research? That could never happen.

  7. Matt G
    Posted February 28, 2012 at 6:59 am | Permalink

    Jerry, what are these other hypotheses about changes in skin pigmentation? Does it have to do with the stratum corneum?

  8. Posted February 28, 2012 at 6:59 am | Permalink

    There is a purely mathematical misconception (which is almost unversal among biologists) embodied in your argument, Jerry. It’s one I have mentioned before here. You said races are not very different because the variation between races is much smaller than the variation within races. This was also Lewontin’s argument in his paper “The apportionment of human diversity”, in which entropy was the measure of “variation” or “diversity”, and similar arguments are usually made today using heterozygosity as the the measure of “variation” or “diversity”. (The between-group variation is calculated by subtracting the within-group variation from the total variation.)

    As anyone can confirm by numerical examples, for both those measures of variation, when within-group variation is high, the between-group variation is ALWAYS small compared to the within-group variation, and the ratio of between-group variation to total variation approaches zero, even if the groups share no genes whatsoever!!!
    The whole science of population genetics (and a vast literature in ecology as well) is based on this misconception that any high school student could disprove by example in five minutes. Kind of embarassing…

    Use Google Scholar to look up [Jost diversity] to learn more about this error and how to correct it.

    Of course, this is a criticism of the argument, not its conclusions. At most loci, diversity is not high, and the races are very similar.

    • aspidoscelis
      Posted February 28, 2012 at 7:13 am | Permalink

      Well, yeah… dividing genetic variation into within-group and between-group portions just gives you an estimate of the relative contribution of each. If one of them goes up, the other one certainly ought to go down!

      This doesn’t tell you anything about the absolute magnitude of differences between groups (e.g., whether or not alleles are shared between two groups), but… it isn’t supposed to.

      • Posted February 28, 2012 at 7:40 am | Permalink

        That is not right. Dividing the total variation into within- and between-group components does depend on the absolute amount of variation, and the within-group variation does not go down just because the between-group variation goes up. And yes, the ratio of between-group to total variation is (wrongly) interpreted to tell us something about the amount of genetic differentiation between the groups. That was Jerry’s argument in the post, and Lewontin’s argument in his article.

        • Posted February 28, 2012 at 7:53 am | Permalink

          “when within-group variation is high, the between-group variation is ALWAYS small compared to the within-group variation”

          But the within-group variation is not always high. And even then, it is always possible for the between-group variation to be higher. Variation is not a finite quantity.

          • Posted February 28, 2012 at 8:04 am | Permalink

            Yes, within-group variation is not always high. That is why I said “when within-group variation is high….”

            For N demes or groups, if entropy is the measure of variation or diversity, between-group variation cannot exceed log N, while within-group variation has no upper bound. So when within-group variation is high (>> log N), between-group variation will always be much smaller than within-group variation.

            If heterozygosity is used as the measure of variation or genetic diversity (as it is in population genetics), then both the within-group heterozygosity and the between-group heterozygosity have upper limits of unity (because heterozygosity is a probability). Therefore whenever within-group heterozygosity is high (close to unity), the between-group heterozygosity (total het. – within-group het.) must approach zero.

            • Patrick
              Posted February 28, 2012 at 11:21 am | Permalink

              “If heterozygosity is used as the measure of variation or genetic diversity (as it is in population genetics), then both the within-group heterozygosity and the between-group heterozygosity have upper limits of unity (because heterozygosity is a probability). Therefore whenever within-group heterozygosity is high (close to unity), the between-group heterozygosity (total het. – within-group het.) must approach zero.”

              Why is that a bad thing?

              For instance, suppose instead of data involving heterozygosity, we have a very simple case: a single locus in a haploid organism and we’re looking at the identify of the allele at that locus for each individual. At one extreme, a single allele could be present in every individual. So we have no grouping information. For any division of these individuals into two groups, both within-group and between-group variation should be 0. At the other extreme, every individual could have a different allele. That still means we have no grouping information. If we divide such a population into two groups, our measure of within-group variation should be 1 (it can’t get any more variable) and our measure of between-group variation should be 0 (there is no grouping information whatsoever). In between those extremes, suppose half the individuals have allele “1″ and half have allele “2″; if individuals are binned by allele, our measure of within-group variation ought to be 0 and our measure of between-group variation ought to be 1.

              There are problems with using heterozygosity as a measure of genetic variation, but the fact that our ability to infer between-group differentiation diminishes as variation within groups increases is not one of them – that’s precisely what should happen. At the upper limit of complete genetic differentiation between all individuals, there is no grouping information; between-group variation -should- approach zero as you approach this upper limit.

            • Posted February 29, 2012 at 8:12 pm | Permalink

              I read your 2008 Mol Ecol paper. Ok, you convinced me :)

              All the cool kids are using Structure now anyway (http://pritch.bsd.uchicago.edu/structure.html).

              • Posted March 1, 2012 at 11:06 am | Permalink

                Thanks for reading it!!! The measure of pure differentiation I derive there has now been generalized to include sequence differences. Stay tuned!

        • Patrick
          Posted February 28, 2012 at 10:59 am | Permalink

          “That is not right. Dividing the total variation into within- and between-group components does depend on the absolute amount of variation”

          Sure, but the magnitude of total variation is not represented in the resulting compartmentalization of x% within-group & y% between-group.

          “the within-group variation does not go down just because the between-group variation goes up.”

          Well, I suppose the total variation could just go up. Hold the total variation constant… or just express it in terms of proportions of total variation, as Jerry does in the original post… and, yes, if between-group variation goes up, within-group variation must go down.

          “And yes, the ratio of between-group to total variation is (wrongly) interpreted to tell us something about the amount of genetic differentiation between the groups. That was Jerry’s argument in the post, and Lewontin’s argument in his article.”

          I think you have this backwards. Interpreting the ratio of between-group to total variation as an absolute measure of differentiation between groups would be wrong. However, there’s nothing wrong with interpreting it as a relative measure of differentiation between groups.

          For instance, you wrote:

          “As anyone can confirm by numerical examples, for both those measures of variation, when within-group variation is high, the between-group variation is ALWAYS small compared to the within-group variation, and the ratio of between-group variation to total variation approaches zero, even if the groups share no genes whatsoever!!!”

          AFAICT, those are properties that a relative measure of genetic differentiation ought to have. They aren’t flaws unless you’re misusing the technique to address some other question to which it is not appropriate. If you want to know whether two groups share alleles, for instance, this isn’t the way to do it. It’s not supposed to be.

          • Posted February 28, 2012 at 12:50 pm | Permalink

            Patrick, thanks for the detailed and interesting comments. You are using a different sense of “differentiation” than I am, almost an opposite sense. To identify which sense is the appropriate one for the argument about races, I took an evolutionary view. If a panmictic population is split by a (possibly leaky) barrier into two demes, the demes will eventually (if the barrier is not too leaky) diverge genetically. If the barrier is complete, they will eventually share no alleles (because of mutation+drift). What relative measure of differentiation tracks that increasing divergence reliably? By a “relative” measure, we should mean a measure that is zero for the first extreme (panmixia) and unity for the end state (no shared alleles). The end state would, if it lasted long enough, generally result in reproductive isolation and speciation, along the lines of Gavrilet’s speciation models. So the question is, where are human races in this continuum? And my point is that we cannot tell this by comparing within-group variation to between-group variation as Jerry did, or by looking at the ratio of additive between-group variation to total variation. I gather you agree with that, you just think it is the wrong question.

            Your argument is that if within-group diversity is very high, the groups are in a sense artificial, because ANY arbitrary division of the population will result in groups that show high differentiation between them. I agree with that, and it is a good point. Nevertheless the answer to the question “Are there genetic differences between a given set of groups?” is yes. This is a question about the absolute differences, and is not answered by the ratio of between-group to total variation.

            Also, suppose we have more than two groups. Suppose there are lots of groups, all but one of them fixed for the same allele. The odd one out is fixed for a different allele (to ensure that we don’t divide by zero when dividing by total variation). Now the measure of relative differentiation you support is equal to unity, indicating maximum relative differentiation. What does that mean? The population shows almost no differentiation between groups; most groups are genetically identical. These groups would be more differentiated if each were fixed for a unique allele. So I am puzzled , it seems your ratio is not a reasonable measure of relative differentiation, at least in the sense relevant to this discussion. Am I misunderstanding something you said?

            • aspidoscelis
              Posted February 29, 2012 at 12:46 pm | Permalink

              Perhaps the two relevant questions are:

              1) How different are genotypes in the groups in question?

              2) To what extent do our data indicate that whatever differences exist are in fact due to divergence between groups?

              AFAICT, you’re interested in answering the first question. This does seem like a useful thing to know, but in isolation I do not think it gets us very far. Measures like Fst are designed (though perhaps not ideally) to address the second question; which, to my mind, is more evolutionarily informative. It is a relative measure in a different sense than that you’ve indicated – i.e., it tells us how genetically distinct groups are relative to the observed variation and its distribution among sampled individuals. What sense we make of genetic divergence should depend to a large extent on the amount and distribution of variation. For instance, in a simple haploid one-locus example, if all individuals have different alleles the fact that groups pulled from that sampling do not share alleles is not informative about divergence between groups. None of that variation can be attributed to group-level dynamics, since there is no grouping information present – all individuals are different.

              If we look at differentiation among groups of humans, knowing the answer to question “1″ does not, of itself, tell us if races are real biological groupings. High variation between individuals in the sample as a whole could lead us to conclude that the groups are genetically distinct (and evolutionarily divergent!) even if variation is distributed randomly. On the other hand, methods like Fst that address question “2″ are specifically designed to identify non-random distributions in which genotypes are relatively homogeneous within groups but heterogeneous between groups. That is the kind of distribution that can allow us to identify group-level divergence.

              Or, in other words, answering question “1″ tells us about pattern only; answering question “2″ is more useful for linking that pattern to a process.

              “Also, suppose we have more than two groups. Suppose there are lots of groups, all but one of them fixed for the same allele. The odd one out is fixed for a different allele (to ensure that we don’t divide by zero when dividing by total variation). Now the measure of relative differentiation you support is equal to unity, indicating maximum relative differentiation. What does that mean? The population shows almost no differentiation between groups; most groups are genetically identical. These groups would be more differentiated if each were fixed for a unique allele.”

              How much variation is observed in a sample plays a key role in our ability to identify groups, and is something we must account for. At the extremes, if we gather genotypes for a sample of individuals and find no variation, maybe there are no genetically distinct groups within the sample, or maybe we just happened to choose a locus (or loci) that shows very low variation regardless of how genetically distinct individuals are in the genome as a whole. Alternatively, if we gather genotypes for a sample of individuals and find that all individuals are completely different, maybe each individual was pulled from a genetically distinct group, or maybe we just happened to choose a locus (or loci) that varies tremendously even if the rest of the genome is pretty homogeneous among the sampled individuals. Asking only how much variation exists between groups provides absolutely no ability to distinguish these alternatives. What we (or at least, I) really want to know is: given that we have observed some level of variation among individuals, to what extent can we infer that there are groupings of individuals within the sample? I don’t think any methods can answer this question perfectly, but some are at least designed to do our best to disentangle grouping information from various other factors (things like mutation rate and size of the available character space for the loci sampled).

              “So I am puzzled , it seems your ratio is not a reasonable measure of relative differentiation, at least in the sense relevant to this discussion. Am I misunderstanding something you said?”

              If we have putative groups and some observed data, and all of the data can be attributed to divergence between the putative groups, that’s what I would call maximum group-level differentiation. It is maximal relative to how much variation is observed; it is not maximal relative to how much variation might have been observed in a different, hypothetical, data set (e.g., some other locus that evolves more rapidly).

              • Posted March 1, 2012 at 11:33 am | Permalink

                If you can answer your Question 1 quantitatively, and you can connect the answer to the demographic and genetic variables describing the groups (migration rate, mutation rate, group size, number of groups), then you have the answer to your Question 2. It is as easy to connect pure differentiation to those parameters as it is to connect Gst or Fst to them.

                Ayala did an interesting study many years ago (I am travelling so I do not have the reference at hand) applying a measure of pure genetic differentiation to populations, subspecies, and species of fruit flies. He also did breeding tests to see if the groups being tested were interfertile. He found that the measure of pure differentiation (the same one I derived) described very well the degree of distinctness of these forms as measured by inter-form fertility. True species (exhibiting complete reproductive isolation) showed values of differentiation near unity, while completely interfertile forms showed small differentiation. These results would not have been the same using Gst or Fst; the results would have depended on the within-group diversity of the locus.

    • TJR
      Posted February 28, 2012 at 9:13 am | Permalink

      Just did the google scholar search and had a look at a couple of the papers. Interesting stuff.

      I used and reviewed diversity indices for my PhD 20 years ago and have been surprised ever since to see the same flawed indices being used.

      I concluded that the Smith and Grassle expected species index was the best (your Hurlbert-Smith-Grassle index I guess) as it had an unbiased estimate and was directly related to the number of species.

      I didn’t think of it in the same way as you have, but it seems we both reached similar conclusions that in some sense the number of species is an appropriate “scale” for diversity.

      • Posted February 28, 2012 at 10:43 am | Permalink

        Thanks for checking out the articles. The difficulty with the measure you mention is that I can’t figure out how to partition it into within- and between-group components. And it doesn’t obey the replication principle. But it turns out that the Hurlbert-Smith-Grassle measure is a (complicated) function of the measures I advocated in my articles. So they are closely related.

    • Calypte
      Posted February 28, 2012 at 7:42 pm | Permalink

      Bird et al. 2011 compared the performance of both the recommended method of genetic differentiation by Jost 2008 (D sub est) and the more tradition fixation indices in their ability to detect genetic differentiation in simulated populations. In short, they found that no one metric was consistently the most accurate in reflecting genetic differentiation, and recommended using a combination of (D sub est) and the old F and G fixation indices.

      Link to article:
      http://www2.hawaii.edu/~cbird/files/Download/Bird%20etal%202011%20Detecting%20and%20measuring%20genetic%20differentiation.pdf

      • Posted February 28, 2012 at 8:19 pm | Permalink

        Actually they found that it depended very much on the question being asked. When the question is about genetic differentiation rather than nearness to fixation, they recommend my D. “It is immediately apparent for all comparisons in Figure 7B–E, regardless of haplotype diversity
        and genetic distance between populations, that Dest is the most consistently accurate measure of
        genetic differentiation.”
        This is one of the most conceptually clear articles comparing my approach to the traditional one based on Jerry’s comparison of within- and between-group variance, but the authors do make one mistake worth noting. They state that a high value of Fst represents nearness to alternate fixation (each deme fixed for a different allele). If this were true, then Fst could be considered a kind of differentiation measure when diversity is low. However, Fst =1.00 even if nearly all demes are fixed for the same allele. Thus it fails to work as a measure of differentiation at both the low-diversity regime and the high-diversity regime (and everywhere in between).

    • Diane G.
      Posted March 1, 2012 at 3:21 am | Permalink

      Isn’t this the same error we make when we say the diversity within a human sex is greater than that between them? Therefore, what? Sexual dimorphism doesn’t exist?

      • Diane G.
        Posted March 1, 2012 at 3:27 am | Permalink

        Or rather, human sexes don’t exist? (I acknowledge that the division isn’t always clearcut.)

  9. Griff
    Posted February 28, 2012 at 7:01 am | Permalink

    I recently stood in Tianamen Square and looked out onto a sea of people with dark hair and dark eyes. It’s difficult to contrast this with Trafalgar Square, because of the level of immigration into the UK over the past 20 or 30 years, but I imagine if you could go back 200 years, the image you would see would be very different from that which I saw in China. Of course there are geographic differences, however we choose to label these differences. Denying this jsut seems silly.

    • Dominic
      Posted February 28, 2012 at 7:08 am | Permalink

      Might have been a lot of hats…but …you would have had trouble as the square was laid out in the 1820s! ;)

      • Griff
        Posted February 28, 2012 at 8:09 am | Permalink

        Well, you know what I mean!!

        Did you check that in Wikipedia or did you already know it ;-)

        • Dominic
          Posted February 28, 2012 at 8:33 am | Permalink

          I knew it was not there but had to check the dates! 50/50

    • Diane G.
      Posted March 1, 2012 at 3:23 am | Permalink

      Denying this just seems silly.

      Hear, hear.

  10. vel
    Posted February 28, 2012 at 7:01 am | Permalink

    fascinating. I wonder if some of the genetic differences will eventually explain some of the unexpected rejection of donor organs. IMO, “race” means different, not better or worse.

    • Posted February 28, 2012 at 7:32 am | Permalink

      This medical application is one place where the incorrect math I mentioned in my Comment 8 is common, and puts human lives at risk. There are medical journal articles full of tables of genetic “differentiation” Gst (between-group variation divided by total variation) between different ethnic groups. These are all nonsensical for the reason I gave in #8.

  11. Schenck
    Posted February 28, 2012 at 7:13 am | Permalink

    “In view of the morphological and genetic differences among human populations, how can such differences be “constructs”?”

    Race is almost never defined after a scientific sampling of genetic differences and ancestral history. It’s almost always defined culturally. So it seems like race, as anyone actually means it, is socially constructed. There might be biological races out there, but I don’t think anyone would agree that Uighyurs and Italians are the same race.

    Also, what does the K5 separation of middle eastern types show? Does it show races or does it show populations that are extremely well mixed? And if we accept that you can have a set of races, but that they’re very mixed together, then what do you even have? And what does it say if one person IDs one array of races and another person IDs another array, etc etc? If we were talking about species, we’d say ‘none of you are able to identify species, to answer the species question’.

    I suppose one of the things that makes analysis here especially difficult is that, on the one hand you have lineages, and that implies that you’re going to have something like ‘races’. On the other hand, different from species (at least the type most of us think about) you have massive horizontal transfer between these lineages.
    Considering that, apparently, anatomically modern humans were interbreeding successfully with Neanderthals, Denisovans, and who knows what else, ‘race’ probably isn’t going to mean much. Heck perhaps the only real race was ‘neanderthalensis, sapiens, denisovan, erectus, florensis’ and the like.

    • Dominic
      Posted February 28, 2012 at 7:15 am | Permalink

      Regarding Neanderthals -
      http://www.bbc.co.uk/news/science-environment-17179608

      • Paul Hampson
        Posted February 28, 2012 at 2:17 pm | Permalink

        I know there isn’t a huge amount of material to work with, but 39 samples seems pretty small to confidently arrive at the results presented for such an extended period. I see their findings as a hypothesis worth testing, but hardly conclusive. Part of the problem with news articles, even scientific ones, is they usually leave out the “tentative finding,” and “needs more work” caveats.

    • Diane G.
      Posted March 1, 2012 at 3:32 am | Permalink

      Race is almost never defined after a scientific sampling of genetic differences and ancestral history. It’s almost always defined culturally.

      Au contraire. While that may hold some truth for Homo sapiens, the biological term “race” has a much older pedigree. As an erstwhile botanist, I decry the loss of the utility of the concept of races in dealing with intra-species diversity in humans just because our culture has demonized the concept.

      • Nick Evans
        Posted March 1, 2012 at 4:32 am | Permalink

        Are you sure? The word “race” has been used to describe people from a common grouping since around 1600 or so.

        • Diane G.
          Posted March 2, 2012 at 12:36 am | Permalink

          The very briefest of plunges into online etymologies shows you’re exactly right. In fact, the first one I looked at dated back to 1500 in relation to human lineages…

      • Schenck
        Posted March 1, 2012 at 7:28 am | Permalink

        Again, I understand that the word has a biological meaning. On the other hand, that’s not how it’s actually used. Race in humans is almost never determined by scientific methods; they don’t cite the paper above when trying to determine what race a person is, for example.

        Also, as an aside, Darwin often refered to sub-species divisions, somewhat equivalent to ‘race’, as ‘sports’. I don’t really have much to say about that, other than that its interesting and quaint.

        • Diane G.
          Posted March 2, 2012 at 12:41 am | Permalink

          Yes, you’re right about different meanings.

          IIRC, “sports” is used today, in horticulture, at least. But it refers to spontaneous oddities rather than races; again IIRC. I suppose such oddities can and are cultivated into races tho.

  12. Dominic
    Posted February 28, 2012 at 7:14 am | Permalink

    I wonder how different the subspecies of tigers were or are – superficially they appear to differ in size, and colour slightly? Human differences are surely the work of the pump of climate changes, pushing population movements & changing, or opening & closing geographical barriers to human or other animals mixing.

    What about Y chromosome ‘races’, or mitochondrial ‘races’ – are they not equally as meaningful or pointless?

  13. Wildhog
    Posted February 28, 2012 at 7:25 am | Permalink

    Wow, thanks for a great post on a contoversial topic.
    i always get the feeling that those who deny that race exists are doing so because they believe that doing so will make racism go away. Well, technically it would.. you cant hate based on race if there is no race. but it wouldnt make the hate go away, we’d just have to find a new name for it. Racism is far too serious a problem to try to solve with symantics.

  14. TJR
    Posted February 28, 2012 at 7:34 am | Permalink

    Agree entirely, and for just the reasons you say.

    Essentially they are saying that there are only very small differences between races, therefore races do not exist. Wouldn’t it make more sense to say that there are only very small differences between races, therefore the differences between races are small?

    That said, I would argue that race, like nationality, is a trivial detail in itself. They only matter because they are the carriage mechanisms of culture.

    • Diane G.
      Posted March 1, 2012 at 3:35 am | Permalink

      They can also matter because they indicate different susceptibilities to diseases, liklihoods of inheriting certain disabilities, differential responses to medications, etc., etc….

  15. paul
    Posted February 28, 2012 at 7:43 am | Permalink

    “I’m not aware that anybody has tested the accuracy of diagnosing a single indvidual’s geographic origin from her multilocus genotype; if such studies exist, please let me know.”

    There’s “Genes Mirror Geography within Europe” By Novembre et al. in Nature 456,98-101.

  16. OldFuzz
    Posted February 28, 2012 at 7:46 am | Permalink

    Within the species, maize, there are hundreds, some estimate more than one thousand races, each acclimated to its particular locale. Using this as a reference, there were human races, but less so today.

    Like maize, humankind began from other species, and through geographical dispersion developed distinguishing characteristics.

    My first contact with this question was in the sixties discussing Mantagu’s Man’s Most Dangerous Myth: The Fallacy of Race.

  17. Posted February 28, 2012 at 7:57 am | Permalink

    I’m not aware that anybody has tested the accuracy of diagnosing a single indvidual’s geographic origin from her multilocus genotype; if such studies exist, please let me know.

    https://www.23andme.com/ancestry/origins/

    (not plugging their services, btw; I’d wait for the full genome sequencing to come down in price myself)

    • Dominic
      Posted February 28, 2012 at 8:36 am | Permalink

      1,000 of your hard earned dollars will buy you this -http://www.popsci.com/technology/article/2012-02/new-disposable-dna-sequencer-runs-molecular-analysis-powered-usb

  18. George
    Posted February 28, 2012 at 8:06 am | Permalink

    I think you have exposed the problem with racial definition of humans. The term race is ill defined in social context even if an ambiguous defintion is satisfactory in scientific study.

    Is someone of a race if the are not geographically isolated anymore. That is race cannot be an individual characteristic rather only a population characteristic.

    If there is a group of humans with morphological distinction living in relative isolation, then you might define that group as a race. If one member leaves and moves elsewhere, breeds with other humans not from that group. They have now changed there race.

    They may well have geneic ancestry that ties them to that group.

    Otherwise, you are saying that any morphological distinction defines race regardless of the population. So now tall people are a race distinct from short people. which perhaps we knew from an old song….

  19. ChasCPeterson
    Posted February 28, 2012 at 8:36 am | Permalink

    Thank you for this: a perfectly straightforward presentation of a perfectly sensible approach. I’ve lost friends over this argument. A lot of people seem to think that the empirical study of human population genetics ended, or should have, with Lewontin 1972.

    None of the genetic facts contradict the concept of socially constructed race concepts, of course. It’s just an acknowledgment that some aspects of some socially constructed race concepts do have a biological foundation.

    In WEIT I float the idea that sexual selection may be responsible: mate preferences for certain appearances differed among regions, leading to all those physical differences that distinguish groups.

    Credit where due, wasn’t this the original argument of C. Darwin 1871?

    • Posted February 28, 2012 at 9:04 am | Permalink

      Also, as I pointed out in #8, Lewontin’s 1972 study is based on invalid mathematical reasoning.

      • Diane G.
        Posted March 1, 2012 at 3:38 am | Permalink

        Can’t be repeated often enough.

  20. Kevin
    Posted February 28, 2012 at 8:44 am | Permalink

    I’ve always been fascinated by the genetics of skin tone.

    Why is it that the skin tone of a child is midway between that of racially different parents?

    Barack Obama is a much lighter skin color than his father and much darker than his mother.

    Same with Tiger Woods.

    Same with every other “mixed race” (for lack of a better term) child.

    Why should this be so? Most other physical features aren’t a “blend”. If they were, all of Mendel’s peas would have ended up being a blended color. And Jerry’s beloved fruit flies would have pink eyes, not either red or white.

    I have never been able to get a satisfactory answer to this question.

    • Posted February 28, 2012 at 8:55 am | Permalink

      I have wondered about that too. No idea.

    • TJR
      Posted February 28, 2012 at 8:59 am | Permalink

      Skin colour doesn’t always blend. Last year I was surprised to discover that Ryan Giggs is mixed race. He looks entirely white, though in retrospect there is a slight clue in his hair.

    • Posted February 28, 2012 at 9:04 am | Permalink

      I know a large West Indian family where both parents skin tone is halfway between black and white and the children’s range form nearly completely white to nearly completely black.

    • Sigmund
      Posted February 28, 2012 at 9:07 am | Permalink

      Because skin tone is caused by more than one gene. A child who had one white parent and one black parent will therefore have a mixture of alleles rather than having a single dominant gene for dark skin.

      • Kevin
        Posted February 28, 2012 at 10:01 am | Permalink

        You say that so confidently — yet I’ve never seen any study that identifies which genes are responsible and why the “blended” phenotype would be the norm.

        A quick search finds a claim that as many as 16 different genes are responsible for eye color…why then don’t I have a blue-eye-hazel-eye mix?

        • Sigmund
          Posted February 28, 2012 at 10:38 am | Permalink

          Here’s a review that discusses pigmentation genes.
          http://www.ncbi.nlm.nih.gov/pubmed/19297406
          I also disagree that you are seeing a ‘blended’ phenotype for the simple reason that the offspring of the next generation (i.e. a mixed (black-white) race individual producing children with a white person) are usually not halfway between their parents. They are either the same color as the mixed race parent or the same color as the white parent. This is consistent with a model suggested (i.e. skin color involves a combination of several different genes).

          • Matt G
            Posted February 28, 2012 at 6:53 pm | Permalink

            There are something like four genes which control the levels of the two pigments eumelanin and pheomelanin.

            • Posted March 1, 2012 at 3:47 pm | Permalink

              I seem to remember the simple model in the elementary genetics book I got from a friend years ago uses a four gene approach, so there are sort of 16 possible “phenotypes” for skin colour. From what I remember, eyes are much simpler, despite the greater variation in colour.

    • Posted February 28, 2012 at 11:26 am | Permalink

      It isn’t so, you just haven’t seen it. See some discussion of this topic here. Also I don’t have the time to fully understand this, but it might be relevant as well.

      Also there was a great explanation of the genetics of color at Pharyngula recently. It’s about flies, but a commenter or two mention human eye color.

    • Nick Evans
      Posted February 29, 2012 at 6:06 am | Permalink

      It isn’t so. My wife and I are different “races”. She’s darker than I am, our daughter is paler than either of us, and our son is darker than either. This isn’t uncommon in our, fairly well mixed, area of London.

    • Diane G.
      Posted March 1, 2012 at 3:39 am | Permalink

      Your comment is all anecdote, no science.

      • DocAtheist
        Posted March 1, 2012 at 9:14 am | Permalink

        If I recall correctly from medical school, some time back, there are eight pairs of genes controlling skin color, so mixes and matches do tend to blend.

        • microraptor
          Posted March 1, 2012 at 11:58 am | Permalink

          That’s what my genetics class textbook says.

        • Diane G.
          Posted March 2, 2012 at 12:33 am | Permalink

          Yes, I didn’t mean to sound so snarky. I was just “in a mood,” and something about this “I’ve always wondered” approach made me wonder why Kevin hadn’t bothered to avail himself of all the copious resources out there…

  21. Posted February 28, 2012 at 8:56 am | Permalink

    You write that “The Mismeasurement of Men” is flawed – I just bought it :/ Can anyone provide me with a link to a discussion of why this book is flawed?

    • Persto
      Posted February 28, 2012 at 12:23 pm | Permalink

      Gould contended that intelligence testing was an integral feature in the adoption of the Immigration Act of 1924–restricted immigration to the US. However, that has been proven to be almost entirely incorrect.

      I am sure you can Google the subject to find a more precise explanation.

  22. Posted February 28, 2012 at 9:12 am | Permalink

    Race and species are two words that are defined differently by different people. Even the “scientific definition” is ever changing and ambiguous. The concepts of race and species are like the concept of the color spectrum. When does one color turn into another, when does white turn into black, exactly when does night turn into day or the tides change? Attempting to answer these questions is futile, or at best non-conclusive.

    When You Know When

    When does day turn into night?
    When does wrong turn into right?

    When does love turn into hate?
    When does early turn into late?

    When does the tide change its course?
    When does winter lose its force?

    We don’t know exactly when
    little boys turn into men.

    We fool ourselves if this we think
    that there is some point so distinct
    that makes you black and makes me white,
    that makes me dumb and makes you bright.

    So when we think that we know when,
    we may well be wrong now and then.

  23. Posted February 28, 2012 at 9:12 am | Permalink

    I’d be interested to see Larry Moran weigh in again on this; I think that he agrees with Jerry Coyne.

    Thank you for this detailed post; I too read the review and came away puzzled; I wasn’t sure how mainstream biologists thought of this.

  24. Jeremy Nel
    Posted February 28, 2012 at 9:19 am | Permalink

    The medical applications of “racial genetics” are even broader than alluded to here. Theoretically, EVERY SINGLE disease has a genetic component somewhere down the line. If not the classic Mendelian-type diseases (which Jerry mentions, but which are usually rare), then there will still be genetic differences in the host response to the exact same disease process (whether infectious or non-infectious) or to the same treatment.

    Just to choose two common conditions, it has been shown that there are genetic racial differences in responses to anti-hypertensives, as well as cardiac failure medications. Putting it more bluntly, doctors already know that the best way to treat a black patient with one of these conditions is often different to the best way to treat a white patient with the same condition. Knowing this sort of information saves lives.

    • Diane G.
      Posted March 1, 2012 at 3:41 am | Permalink

      Hear, hear.

  25. TJR
    Posted February 28, 2012 at 9:30 am | Permalink

    One thing we do need to beware of is that, even if a drug or treatment has no effect at all, if you slice and dice the results (male v female, white v black etc etc) enough then the problem of Multiple Comparisons and Simpson’s Paradox can easily make it look as though there is a difference between (for example) races in the effect of the drug even when there is not.

    • John Scanlon, FCD
      Posted March 1, 2012 at 6:13 am | Permalink

      One word: Bonferroni

  26. davidintoronto
    Posted February 28, 2012 at 9:40 am | Permalink

    Fair to say that (to a degree) the “politics” on this influences the individual sciences differently?

    When a forensic anthropologist says that a skeleton is a male Asian, this seems fairly objective. And few would claim that the information, in this context, isn’t useful.

    On the other hand, what does someone actually do with comparative intelligence studies?

    • Tim Harris
      Posted February 28, 2012 at 5:01 pm | Permalink

      They try to use them to assert that policies they disagree with for political reasons – eg affirmative action – should be discontinued. This is something that Andrew Sullivan, who is not inhumane or a racist himself (I think), bangs on about. And there’s somebody called Steve Sailer, as I recall, who genuinely is racist and bangs on about studies of comparative intelligence. I’m surprised he hasn’t contributed any little apercus here yet.

      • E.A. Blair
        Posted February 28, 2012 at 5:07 pm | Permalink

        He did, in comment #45, with a link to the vdare web site.

  27. Posted February 28, 2012 at 9:48 am | Permalink

    (subscribing)

  28. Steve Smith
    Posted February 28, 2012 at 9:59 am | Permalink

    What are the implications of these differences?

    It shouldn’t be controversial to observe that an algorithm can look at a person’s genetic makeup and with very good odds determine where their ancestors are from.

    But beyond k-means clustering, it’s also important to measure the fraction of genetic variance determined by race versus the variation observed in the entire population. The fixation index FST does this, and when you measure the genetic difference between human races, racial variance only accounts for 10–20% of human genetic variance at most (difference between Africans and Australians from the rest), with significantly smaller differences between other races.

    FST measurements support JC’s views on the existence of race, but they also quantify just how silly racial theories and prejudices are.

    • Posted February 28, 2012 at 11:39 am | Permalink

      Steve, I guess you didn’t read my Comment 8. Fst and Gst are based on serious misconceptions about the mathematics of diversity and differentiation, and do not measure differentiation between groups. Fst can approach zero (supposedly indicating no differentiation) even when the groups share no alleles. If we look at high-diversity loci, Fst will always be near zero, even if the groups belong to entirely different species. You cannot argue from Fst that racial differences are small.

      By the way, Fst or Gst can equal unity even if almost all groups are fixed for the same allele, which makes it even more useless.

      See my article, “Gst and its relatives do not measure differentition”, (2008) Molecular Ecology 17: 4015–4026, and the many articles that have built on it over the last few years. Or check out the Nature Population Genetics Forum for much discussion of the topic.

      • Steve Smith
        Posted February 28, 2012 at 12:50 pm | Permalink

        Whether they’re based on misconceptions or simplifying assumptions about the diversity of the underlying populations, there certainly are several other mathematically superior models, all of which to my knowledge lead us to the same conclusion about human populations. Wikipedia, my italics:

        Long and Kittles find that rather than 85% of human genetic diversity existing in all human populations, about 100% of human diversity exists in a single African population, whereas only about 70% of human genetic diversity exists in a population derived from New Guinea. Long and Kittles argued that this still produces a global human population that is genetically homogeneous compared to other mammalian populations.

        • Posted February 28, 2012 at 1:00 pm | Permalink

          That’s fine, I am not really saying anything about the actual differentiation (which I know nothing about). I am just trying to get us to stick to valid arguments. Arguments based on Fst such as you made are not valid arguments about the amount of genetic differentiation between races. (And this lack of validity doesn’t depend on model assumptions. It is a basic mathematical problem of mistaking Fst as a measure of genetic differentiation.) Your conclusions, though, could still be valid by accident.

          • Steve Smith
            Posted February 28, 2012 at 1:55 pm | Permalink

            That genetic variation between human populations is measurably small is a valid argument, whether you estimate this variation using the measures FST, GST, or your own D (each having its own strengths and flaws). We should not expect, and do not see, a big difference with these measures applied to different races because total human genetic variation itself is small, having gone through the out-of-Africa bottleneck. This example doesn’t match the valid high-diversity counterexample. There’s a whole bunch of complicating factors to account for: mutation rates, independence, number of genes, and so forth. GST is still a useful measure of genetic differentiation—a comment on Jost’s D:

            D is not a useful measure when interest is focused on demographic processes such as genetic drift and migration

            Nevertheless, I’d expect the same conclusions whether we measure racial differences using D or the traditional ones.

            • Posted February 28, 2012 at 2:28 pm | Permalink

              Again, I was not criticizing your conclusions, just the method of reaching them via Fst or Gst alone. One other comment on Fst or Gst: even when diversity is very low (all demes fixed for a single allele), it still doesn’t measure the actual differentiation between demes; if there are 100 demes, with 99 of them fixed for the same allele, and the 100th deme fixed for a different allele, this would be a very homogeneous set of demes (99% of them are genetically identical), but Gst would equal 1.00, indicating maximum differentiation.

              As for the Ryman and Leimar article you mention, I hope you have read the article of mine that rebuts it (mine follows the article you cited). Gst is not a measure of the differences in gene frequencies between groups. And Ryman and Leimar’s negative conclusions about a real measure of genetic differentiation (like my D) are backward; real measures of differentiation don’t connect to Ryman and Leimar’s favorite demographic factors because those are not the factors that influence divergence. See my simulations in the Comment section of the following post on the Molecular Ecologist blog for graphic proof:
              http://www.molecularecologist.com/2011/03/should-i-use-fst-gst-or-d-2/

  29. evogene
    Posted February 28, 2012 at 10:13 am | Permalink

    “While I think there may be statistical differences among races in these things, it’s not as obvious that sexual (or natural) selection would operate as strongly on genes involving these traits as on superficial external characteristics”
    I don’t think that IQ or intelligence is a trait in the same sense as hair color is, but I think that regardless of what differences there are, they don’t by any means imply determination. That is what racism tries to impose, which is false.

    • microraptor
      Posted February 28, 2012 at 11:02 am | Permalink

      Exactly.

      Intelligence is a very subjective trait. If I were compared to a New Guinea native (because I just reread Guns, Germs, & Steel a few months ago), I probably beat said person on a writing or mathematics test, but not because I’m Caucasian but because I was born into an upper-middle class American family and therefore received a good quality education that was focused on those subjects.

      The New Guinean, conversely, would blow me out of the water on any test focused on things like finding food or constructing a shelter in New Guinea. Again, not because of genetics but because that’s what their education would have consisted of.

      • Derek
        Posted February 28, 2012 at 11:20 am | Permalink

        Thanks Microraptor, you’ve made the point I was going to. You can almost put quotes around “intelligence”, because it means different things to different people and because its measurement is so culturally sensitive. My guess, and it is a guess since I’m not in the field, is that even the non-verbal tests are still culturally (and economically) sensitive – the patterned-block arranging test, for example, would seem to select for cultures that play with blocks and people that can afford them.

  30. Jim Thomerson
    Posted February 28, 2012 at 10:16 am | Permalink

    I have no idea if this is still the story. Say 40 years ago, the story of black vs white skin color involved two pairs of genes, based on a study in Jamaica, perhaps. Call the genes B1,b1 and B2,b2. B1B1B2B2 would be black, b1b1b2b2 would be white. Various crosses would give a number of combinations, the more B’s the darker, the more b’s the lighter.

  31. Posted February 28, 2012 at 10:27 am | Permalink

    Are there human races?

    Yes, sure – at the olympics and at other sporting events.

    There is so much gene mixing in an era where air travel is common, that I think the idea of races of humans has lost any value it may once have had.

  32. ThyroidPlanet
    Posted February 28, 2012 at 10:33 am | Permalink

    IIUC

    dog breeds are not separate species because they are reproductively compatible (ref. below).

    aren’t all extant Homo sapiens reproductively compatible? why not use “breed” instead?

    ref:
    http://whyevolutionistrue.wordpress.com/2011/11/13/dog-breeding-the-debasement-of-the-american-cocker-spaniel/

    • Posted February 28, 2012 at 10:47 am | Permalink

      Hmm… because it sounds too much like eugenics…

      /@

    • Dave
      Posted February 28, 2012 at 11:01 am | Permalink

      I’ve always felt that dog breeds are a good analogy for human races. Different varieties of dog “breed true”, i.e. cocker spaniel parents will always have cocker spaniel pups, never great danes or chihuahuas, yet given the chance all types of dog will happily interbreed with each other. As a result, there exists every shade of intermediate, and many dogs can’t be assigned to any specific breed at all. This seems to parallel the human situation quite closely, although dog breeds are far more divergent physically than human races.

      Yet for some reason when I’ve made this argument in company I sometimes get disapproving comments. It’s as if for some people even the idea of “race” is a kind of taboo, and anyone who suggests there may be some validity to the concept is obviously a Nazi.

  33. Hempenstein
    Posted February 28, 2012 at 10:50 am | Permalink

    Tangentially related, I guess, Ötzi the Iceman’s genome has just been released. He has modern descendants in Corsica/Sardinia.

    • David Marjanović
      Posted February 29, 2012 at 10:56 am | Permalink

      He doesn’t. Corsica and Sardinia were just settled by the same people that he descended from.

  34. Ken Pidcock
    Posted February 28, 2012 at 10:51 am | Permalink

    I’m inclined to acknowledge that there have been human races but, as human populations become less allopatric, it becomes increasingly less useful to use race in considering the human experience.

  35. Jim Thomerson
    Posted February 28, 2012 at 11:09 am | Permalink

    Ernst Mayer had an equation for figuring if two populations are different enough to be recognized taxonomically as subspecies. I used it a good bit in days gone by, but do not remember it and cannot find it. It involved means and standard deviations, I think. Anyone know it?

    • David Marjanović
      Posted February 29, 2012 at 10:58 am | Permalink

      I don’t know it; just be aware that subspecies (well, like species, only even more so) are a very subjective group of concepts; there are taxonomists that don’t even use the term at all.

      BTW, he’s spelled Mayr.

  36. Spacepenguin
    Posted February 28, 2012 at 11:24 am | Permalink

    Hello, I was wondering if you could represent gene clustering with contour lines? That is if you take the genetic difference, on average, between populations and plot it as though it was a height difference as you would two hills on a map.

    Perhaps there is some reference genome that could act as a sea level equivalent?

  37. Dan L.
    Posted February 28, 2012 at 11:29 am | Permalink

    Just wanted to point out that “socially constructed” vs. “biological” concepts of race is a false dichotomy. In the OP, Jerry explains that there could be a biological basis for race. As other commenters have observed, the distinctions (in particular which genetic loci you use for the sorting) are actually arbitrary so this exercise is less discovering the genetic basis of race and more defining the genetic basis of race.

    But biological race is not what most people have in mind when they think about “race.” Just because there may be some biological basis for talking about race does not mean there is not at the same time a socially constructed concept of race, and the socially constructed concept is what people react to. For white Americans, black is probably black whether we’re talking about a 1/8th black American mixed-race person or a pure-blooded San villager from Africa. Furthermore, the biological basis of race could not possibly inform the views of the “average person” on race because the “average person” simply does not know enough about genetics for this to be the case. To the extent that race matters in society — i.e. to the extent that it engenders racism — it is the socially constructed concept of race that is in play, not the poorly understood and obscure biological concept of race.

    • Nick Evans
      Posted February 29, 2012 at 6:14 am | Permalink

      Agree with this. The everyday understanding of the word “race” is plainly a social construct based on morphological differences, without regard to any biological differences that may or may not underpin them.

  38. TnkAgn
    Posted February 28, 2012 at 11:42 am | Permalink

    All this takes me back to my Anthro days at the University of Illinois. Not only was “Continental Drift” still cutting edge earth science, but the theories of Carleton Coon, that the “races” separated before becoming Homo sapiens sapiens were still in vogue.
    http://en.wikipedia.org/wiki/Carleton_S._Coon

  39. Mary - Canada
    Posted February 28, 2012 at 12:11 pm | Permalink

    The “sociological constructs” thing is simply political correctness imposed on biological reality.

    Well said and so true

    • Dan L.
      Posted February 28, 2012 at 12:53 pm | Permalink

      Not true. There’s huge mountains of good, peer-reviewed sociological literature on the social construction of race. Again, this isn’t saying that there isn’t necessarily some biological basis, but to deny that there’s any socially constructed aspect to race is even more ridiculous than denying there’s a biological basis.

      • Dan L.
        Posted February 28, 2012 at 12:56 pm | Permalink

        And you can start looking here before arguing with me.

  40. E.A. Blair
    Posted February 28, 2012 at 12:30 pm | Permalink

    For what it’s worth, in 1974 when I filled out my application for college, I got to the section marked “Race:”, and, with typical teenage smartaleckiness checked “Other” and on the write-in line put “Human”. After the application was processed, I received a packet of information with a cover letter that informed me of my eligibility for a number of assistance programs since I had indicated that I was a member of a disadvantaged minority racial group.

    This can be taken as a joke (someone in the registration called me out on my own adolescent humor) or a sad commentary on the times (that humans are a disadvantaged minority).

    For reference, the choices under “Race” were White, Black, Asian, Hispanic, Native American and Other_______________.

  41. DV
    Posted February 28, 2012 at 12:36 pm | Permalink

    >>And, at any rate, any such differences cannot be used to justify racism given the tremendous variation we see in other genes between members of different populations.
    <<

    I would think any differences cannot be used to justify racism, period.

  42. Posted February 28, 2012 at 12:48 pm | Permalink

    In a Mesoamerican studies course I took in Community College, the concept of “clines” over “races” was presented and sort of stuck in my then impressionable and easily indoctrinated (according to Santorum at least) mind. Though I don’t come across this term as much, is it just a politically correct term for race?

    • David Marjanović
      Posted February 29, 2012 at 11:00 am | Permalink

      I think not; it emphasizes that human geographical variation is clinal – that there aren’t obvious places to draw lines.

  43. Jimbo
    Posted February 28, 2012 at 2:37 pm | Permalink

    I thought hair texture (in Africans) has been suggested to be an adaptation against lice and other parasites. I thought sickle-cell anemia has been conclusively mapped to human populations where malaria is endemic and that sickle-cells are less prone to infection by P. falciparum.

    It’s interesting to discuss which hominid ancestor to our current races are different species? Homo sapiens did interbreed with neanderthals which would be really big morphological differences.

  44. Posted February 28, 2012 at 2:58 pm | Permalink

    There are real biological variations in the human species. The problem is that our divisions are inaccurate, or just plan wrong. The original source of error was the Bible. Remember the sons of Noah? Shem, Ham and Japheth. Ham gave rise to Hamites (Africans), Shem to Semites (Middle Easterners) and Japheth to white people (or Caucasians). The writers of Genesis didn’t know much about Asians or Native Americans. Our modern classification scheme (White, Black, Asian, Native American, etc.) is a slight modification of the biblical scheme with a few races added here and there. The divisions are arbitrary because we were unaware of the underlying genetics (and we still are, for the most part).

    There has been, however, some recent developments in analyzing mitochondrial DNA and y-chromosome genetic markers that gives us much more reliable information on human variation. One of the most startling finding is that we are less genetically diverse than we think we are, and there is less genetic diversity in humans then in other primate species. And this is primarily due to the fact that we had very little time to diversify. Humans have experienced a ‘bottle-neck’ sometime around 70,000 years ago in which the world population of the human species was reduced to a few thousand people and only diversified in the past 60,000 years.

    Add to that, the habit of some humans to have sex with humans of other races. Try dividing Brazilians or Mexicans into separate races. There was so much mixing going in Latin America that you could never implement an affirmative action program there. That’s also why the U.S. Census bureau has a separate question for Hispanic origins that now comes before the race question. They essentially gave up and just said “If you have Hispanic background, skip the race question.”

    Check out the Genographic Project at https://genographic.nationalgeographic.com/genographic/lan/en/index.html

    • truthspeaker
      Posted February 28, 2012 at 3:25 pm | Permalink

      Shem, Ham and Japheth. Ham gave rise to Hamites (Africans), Shem to Semites (Middle Easterners) and Japheth to white people (or Caucasians)

      Is that really in the Bible? I thought that was made up by white supremacists within the last few hundred years.

      • Posted March 1, 2012 at 3:52 pm | Permalink

        If I remember, some of it sort of is, like one group being labeled dark (like Moses’ wife!) and the other light. It is the contemporary racists who interpret those with more modern categories, and also take the “mark of Ham” or whatever it is to mean such and such groups (“blacks”, usually) are cursed or something stupid like that.

        • Steve Smith
          Posted March 1, 2012 at 4:26 pm | Permalink

          one group being labeled dark (like Moses’ wife!)

          One little-known great thing about DeMille’s 1956 The Ten Commandments is his inclusion of Moses’ black wife, shown here played by the beautiful Naaman Brown. Though DeMille could not explicitly identify a black women as Moses’ wife in the 50s, the implied intimacy between the Ethiopian princess and Moses is unmistakeable, as is the spiteful glare that Ann Baxter’s Nefretiri gives her competitor in this scene.

          That DeMille cast Moses’ black wife almost makes up for his artistic license taken with the rest of the Exodus story.

        • Diane G.
          Posted March 2, 2012 at 12:44 am | Permalink

          Especially by (at least the early) Mormons, IIRC.

  45. Posted February 28, 2012 at 3:41 pm | Permalink

    Dear Professor Coyne:

    I quite agree, but I also think there’s a second way to think about race. Instead of thinking of races as smaller, vaguer species, it can be quite helpful to think of them as larger extended families that are made more coherent and longer-lasting than the typical extended families we are all familiar with due to some degree of inbreeding. In this view, a racial group is a partly-inbred extended family.

    http://www.vdare.com/articles/its-all-relative-putting-race-in-its-proper-perspective

    • Tim Harris
      Posted February 28, 2012 at 5:07 pm | Permalink

      Ah, he’s here!

    • Tim Harris
      Posted February 28, 2012 at 5:13 pm | Permalink

      Just so you know who he is:

      ‘Sailer’s website is rife with primitive stereotypes. On it, Sailer mocks professional golfer Annika Sorenstam for having well-developed muscles and claims that Asian men have a hard time finding dates because they look “less masculine” than other men.

      ‘Last January, on the hate site vdare.com, Sailer labeled Obama a “wigger.”

      ‘”He’s a remarkably exotic variety of the faux African-American, but a wigger nonetheless,” Sailer wrote. “Even genetically, Obama, whose East African descent is apparent in his unusual features, has only a distant relationship to the West Africans who are the ancestors of almost all African-Americans.” To illustrate his point, Sailer used photos of Obama side-by-side with Jesse Jackson and the rapper Ludacris, “both of whom have conventional West African features.”

      ‘Assessing the tragic aftermath of Hurricane Katrina in September 2005, Sailer wrote, “The plain fact is that they [black Americans] tend to possess poorer native judgment than members of better-educated groups. Thus they need stricter moral guidance from society.”‘

      Yes, as Jerry said, race is a touchy subject, and with people like Sailer around, you can see why.

      • Diane G.
        Posted March 1, 2012 at 3:50 am | Permalink

        Thanks for calling him out, Tim, et al.

    • Dominic
      Posted February 29, 2012 at 2:39 am | Permalink

      Hello Sailer!

    • Steve Smith
      Posted February 29, 2012 at 5:34 am | Permalink

      Steve Sailer said:

      The brutal truth: Obama is a “wigger”. He’s a remarkably exotic variety of the faux African-American, but a wigger nonetheless.

      The funny part: Steve Sailer is a wigger too, a white person descended from black people. Now that we have a confirmed racist at the site, I’d like to ask Steve Sailer how it feels to know that his own ancestors were all niggers. Do racists deny genetics? If they don’t, how do they support their racism? Answers to these questions would be fascinating.

      • doc
        Posted March 2, 2012 at 9:01 pm | Permalink

        My ancestors were single celled organisms.

        • Griff
          Posted March 3, 2012 at 4:12 am | Permalink

          I think mine may have been RNA fragments.

    • Posted March 11, 2012 at 11:10 am | Permalink

      what is this even supposed to mean or contribute? clearly any group – race, nationality, caste – is a partly inbred group. By definition. How does that bring thinking forward?

  46. Sabeer Hassan
    Posted February 28, 2012 at 4:54 pm | Permalink

    I agree with you completely. In fact i urge you to even publish a short review on it. Its time when we should think race with a biological focus, not a sensationalist, cultural one.

  47. Tumara Baap
    Posted February 28, 2012 at 9:55 pm | Permalink

    Giving ammo to racists is a concern, but to counter it one need stubbornly deny the existence of races. There is more to race than the social angle. Purely biological ramifications are also evident. African Americans respond better to blood pressure drugs like calcium channel blockers. Native Americans are predisposed to diabetes. Askenazi jews are disproportionately afflicted by cystic fibrosis and a multitude of CNS disorders. Askenazis are also possibly a bit smarter than the rest of us.
    If the last sentence is true, then it must also be true that some groups/races are stupider than others. But putting it this way is kryptonite. Given the high proportion of genes devoted to brain differences, it would be weirder if there were no variations in symbolic thought or abstract and hypothetical reasoning between groups. I.Q. likely only captures a thin slice of cognition. But even here studies amongst identical twins raised in different homes reveals genes play a huge role. Ditto for sociopathic tendencies. Ditto for abilities in face recognition or spatial memory. They all have their respective bell curves, in line with easily measured physical traits like height. And it is entirely reasonable to expect intangible virtues and deficits of our abilities to cluster within groups.

  48. David Johnson
    Posted February 28, 2012 at 11:05 pm | Permalink

    There is a good discussion of this topic in Nicholas Wade’s book, “Before the Dawn.” His conclusions are like Jerry’s.

  49. TJR
    Posted February 29, 2012 at 7:27 am | Permalink

    This is a comment on the various subthreads discussing diversity measurement between Lou Jost and others, for people “looking in” on them.

    The main problem is that standard diversity measures don’t partition nicely in the way that variance does. Hence when we read things like “only 5% of variation is between populations” it is easy to think that this is like the R^2 in regression or the between group mean square in ANOVA, but it isn’t.

    Sums of squares, used for measuring variation in numerical data, behave beautifully like kittens, you can divide up the various sources of variation nicely and meaningfully. However standard diversity indices, used for measuring variation in categorical variables, don’t have these nice properties, so if you interpret them as though they do then you can easily deceive yourself.

  50. David Marjanović
    Posted February 29, 2012 at 11:12 am | Permalink

    The number of human races delimited by biologists has ranged from three to over thirty.

    I’ve seen a classification with 66 human races. There were really pedantic splitters around in the early 20th century.

    An important issue that I haven’t seen addressed here is that, although many genes show geographic variation in humans, different genes commonly have totally different geographic variation. Skin color doesn’t covary with any blood type, and so on. So why privilege skin color over blood type or anything else? Just because it happens to be visible at first glance? Or why don’t we delimit races based on hair color – just because several colors can be found in most places in Europe (and this state has been prevailing for millennia now), right?

    The mentioned covariation of some medically relevant genotypes with skin color in the US happens to work in the US because most of the slaves shipped to the US came from a rather small area, the coast of northern Angola and a few other patches on the western coast of Africa. I bet if you’d apply this medical knowledge to, say, Ethiopia, it would fail pretty spectacularly.

  51. Frank Notlag
    Posted February 29, 2012 at 12:36 pm | Permalink

    Human intelligence has no doubt been under extremely heavy selective pressures in the last 100k years or so, almost certainly as much so as morphological features like skin color, nose shape or hair texture. To believe that evolution can affect the latter traits but not the former is a matter of ideology or religion, not science. There is no good reason to believe, a priori, that the different geographical and social environments, into which human populations had been relatively isolated for the past 50k years, would all have exerted the same exact pressures on the development of cognitive ability, or that the geographically separated sub-species would all have simultaneously developed the same intelligence-enhancing genetic adaptations regardless of differences in the sizes of their populations or in the cognitive demands of their environment. It is a reasonable hypothesis, for example, that the need of some human populations, once they had migrated out of Africa’s warm climate, to survive long winters of scarcity in northern Ice Age climes, would have brought about psychological changes–for example, a greater capacity to defer immediate gratification, a greater tendency toward long-term monogyny, a disposition toward dispassionate abstract thought, etc. Likewise, it is reasonable to investigate whether the rise of agriculture and state-based civilization would have placed very different selective pressures on the affected human populations, resulting in their differentiation, psychologically, from small hunter/gatherer band-based societies that did not undergo these monumental social changes. It wouldn’t be unreasonable to hypothesize that such pressures have resulted not only in the observed differences in mean IQ among different populations, but in other non-cognitive psychological differences as well (self-restraint, tendency to aggression and criminality, etc). But these reasonable hypotheses can’t even be explored in American academies. To do so is to invite opprobrium and ostracism.

  52. M Pearlstein
    Posted February 29, 2012 at 4:27 pm | Permalink

    Good post. Professor Steve Hsu addressed the moral element of this research a few years ago too:

    “Finally, it is important to note that group differences are statistical in nature and do not imply anything definitive about a particular individual. Rather than rely on the scientifically unsupported claim that we are all equal, it would be better to emphasize that we all have inalienable human rights regardless of our abilities or genetic makeup.”

    http://infoproc.blogspot.co.nz/2007/01/metric-on-space-of-genomes-and.html

  53. DocAtheist
    Posted February 29, 2012 at 7:55 pm | Permalink

    FWIW, and in case no one else said it, yet, human races are like domestic cat or dog species. Very different breeds can cross and too much inbreeding brings out recessive traits, some of which are dangerous.

    I once had a patient with ordinary caucasion appearance, sickle cell anemia and beta thallasemia. He was of southern Italian descent. While SCA is more common in subsaharan Africa, it’s not so uncommon around the Mediterranean.

    Sometimes, I wonder if the antisemitism which accompanied the Disapora, pogroms and Inquisition included, led to some sort of survival of the fittest, or rather, most adaptable of Jews… There were certain adaptations in terms of trades, focusing on those suitable to faster departures and whatever the powers that be limited Jews to having. Perhaps skills developed to suit?

  54. Evgeny Brud
    Posted February 29, 2012 at 8:38 pm | Permalink

    There’s an interesting talk from 2004 by Lewontin called “the concept of race” that’s on youtube. He made some speculations about racial differences that I hadn’t heard before, such as skin color differences being due to sexual selection, and that the ancestors in Africa weren’t necessarily dark skinned.

  55. Bjarte Foshaug
    Posted February 29, 2012 at 11:05 pm | Permalink

    “Racial delimitation could, critics say, lead to a resurgence of racism, racial profiling, or even eugenics.”

    Whether or not there is any reality to race, I can hardly imagine a worse reason for opposing racism. As Steven Pinker has pointed out, when people argue that racism is wrong because there is no such thing as race, what they seem to be implicitly saying is that if races DID exist, racism would not be wrong after all.

  56. Posted March 1, 2012 at 2:06 am | Permalink

    As you note, by any objective criterion there are human races, but that doesn’t imply that they are very important. This is obviously tainted by history. For that matter, sexism is evil but that doesn’t mean that there are no human sexes!

  57. Posted March 1, 2012 at 7:04 am | Permalink

    The problem is that Prof. Coyne is using the terms “race” and “ecotype” interchangeably. But when certain elements of society talk about “race” they do not mean ecotypes. Pigliucci and Kaplan (2003) explains:

    “We argue that human races, in the biological sense of local populations adapted to particular environments, do in fact exist; such races are best understood through the common ecological concept of ecotypes. However, human ecotypic races do not in general correspond with “folk” racial categories, largely because many similar ecotypes have multiple independent origins. Consequently, while human natural races exist [i.e. ecotypes - E. K.], they have little or nothing in common with ‘folk’ races.”

    So “races” are in this sense non-monophyletic form groups. No one is denying that you can group humans according to morphology if you want, but it will not reflect evolutionary ancestry. For instance, “black” African Americans are not more closely related to “black” Polynesians, even though you could technically group them into one form group.

    Kaplan, J. and M. Pigliucci. (2004). On the concept of biological race and its applicability to humans. Philosophy of Science 70: 1161-1172

  58. Posted March 1, 2012 at 7:44 am | Permalink

    Yes. As we all know, there are morphologically different groups of people who live in different areas, though those differences are blurring due to recent innovations in transportation that have led to more admixture between human groups.

    You’ve got that backwards. “Races” emerged from a mostly continuous population of gradients, with the movement of people or the discontinuous observation of people in different areas of the world by naive observers with a race concept already firmly in their minds.

  59. John Harshman
    Posted March 1, 2012 at 1:04 pm | Permalink

    Nick Matzke has a fine reply to Jerry at Panda’s Thumb, one that makes all the points I would have made if I had been enterprising enough to do the work.

    Summary: the mere existence of geographically structured variation isn’t enough to tell us there are races or subspecies. The variation has to separate neatly into discrete bins. If the variation is, on the other hand, clinal (i.e. if the differences between distant areas are the result of isolation by distance, as Jerry in fact mentioned), then you don’t have discrete races. That doesn’t mean people haven’t tried, in other animals as well as humans. But the subspecies descriptions in such cases don’t hold up under examination. Sure, Chinese are different from Europeans. But look in between China and Europe and you will find a fairly smooth transitional series. As Jerry also mentioned, subspecies in other taxa are most often geographically separated from each other, which allows for discrete variation, private alleles, and such. Human populations, on the other hand, have seldom been isolated for very long, with the possible exception of the now-extinct Tasmanians.

    • DocAtheist
      Posted March 1, 2012 at 1:16 pm | Permalink

      Wait: Is that like saying Siamese cats are really no different from Persians?

      • John Harshman
        Posted March 1, 2012 at 2:14 pm | Permalink

        No.

        • DocAtheist
          Posted March 1, 2012 at 2:39 pm | Permalink

          Why not?

          • John Harshman
            Posted March 1, 2012 at 4:27 pm | Permalink

            Was that really a serious question? I thought you were attempting humor. There are several reasons. First, I never said populations were identical. They do indeed differ (though not by much compared with most wide-spread species). But their variation is not into distinct races but just a matter of nearby people being more similar than distant people. A transect across the intervening space would find a fairly smooth set of intermediates. Cat breeds, of course, are nothing like that, being products of artificial selection. The “pure” populations are maintained that way by breeders.

          • Posted March 1, 2012 at 8:38 pm | Permalink

            The mere existence of transitional forms shouldn’t rule out the existence of races or subspecies. It should matter how common the transitional forms are relative to the typical forms. There are rare hybrids even between distinct species (especially in plants).

            • John Harshman
              Posted March 2, 2012 at 8:15 am | Permalink

              That has nothing to do with the point, which is that we encounter a smooth transition in a geographic transect. Not rare hybrids, or even a narrow hybrid zone, but a series of intermediate populations.

    • Mike Pearlstein
      Posted March 1, 2012 at 8:38 pm | Permalink

      ***Human populations, on the other hand, have seldom been isolated for very long, with the possible exception of the now-extinct Tasmanians.***

      What about Aborigines?

      ***If the variation is, on the other hand, clinal (i.e. if the differences between distant areas are the result of isolation by distance, as Jerry in fact mentioned), then you don’t have discrete races.***

      See Rosenberg’s 2005 paper on clines and clusters.

      “For population pairs from the same cluster, as geographic distance increases, genetic distance increases in a linear manner, consistent with a clinal population structure. However, for pairs from different clusters, genetic distance is generally larger than that between intracluster pairs that have the same geographic distance. For example, genetic distances for population pairs with one population in Eurasia and the other in East Asia are greater than those for pairs at equivalent geographic distance within Eurasia or within East Asia. Loosely speaking, it is these small discontinuous jumps in genetic distance—across oceans, the Himalayas, and the Sahara—that provide the basis for the ability of STRUCTURE to identify clusters that correspond to geographic regions.”

      • John Harshman
        Posted March 2, 2012 at 8:28 am | Permalink

        What about Aborigines?

        My understanding is that there has been regular gene flow between Australia and southern New Guinea and other nearby islands.

        discontinuous jumps

        That’s just a little more geographic structuring. And it would indeed result in subspecies/races if there were no contact through or around the barriers (and if that were continued for long enough). But in no case, other than perhaps Tasmania, is that true. Wide oceans have been complete barriers for most of history, but mountains and deserts have not. And in all cases there are corridors of contact — ways around the barrier — even between Eurasia and the Americas. This is just a wrinkle on isolation by distance — some distances are greater than their straight-line separation would suggest. Still no distinct races.

        And let me point out that all it takes to prevent divergence by drift is one migrant per generation, not a very high figure.

        • Posted March 2, 2012 at 9:13 pm | Permalink

          Your claim is false that one migrant per generation is enough to prevent divergence due to drift. That claim is based on the same kind of mistaken reasoning about variation that I criticized in comments above (eg #8, and following #28). The absolute number of migrants has nothing to do with the production of differentiation between demes due to drift.

        • Posted March 3, 2012 at 8:03 am | Permalink

          John, the quantity that determines the equilibrium value of differentiation at a neutral locus in a subdivided population is P/u, the pairwise migration rate divided by the mutation rate. This shows that your absolutist view is wrong; the key quantity is the proportion of the population which migrates, not the absolute number of migrants. And in human populations separated by geographic barriers like large deserts or mountains, the migrants surely make up a very small proportion of the population. That means drift and mild selective pressures can produce strong differentiation.

          • Posted March 3, 2012 at 4:47 pm | Permalink

            I should emphasize the word “can” in my last sentence. I have no idea if there actually are important differences in selective pressures across these barriers. My point is purely mathematical. I just want people to use valid arguments.

      • John Harshman
        Posted March 2, 2012 at 8:30 am | Permalink

        By the way, was “Rosenberg 2005″ a typo for 2002, or were you introducing a new reference? If the latter, could you give the complete citation?

        • Mike Pearlstein
          Posted March 2, 2012 at 11:42 pm | Permalink

          @ John Harshman,

          The 2005 Rosenberg paper is:
          Clines, Clusters, and the Effect of Study Design on the Inference of Human Population Structure published in the December 2005 Issue of PLoS Genetics.

          **Still no distinct races.**

          You are creating a straw man no? See Sesardic.Biology and Philosophy 25 (2010), 143-162.

  60. Francois
    Posted March 2, 2012 at 10:38 pm | Permalink

    “DNA and other genetic analyses have shown that most of the variation in the human species occurs within a given human ethnic group, and only a small fraction between different races.”

    You know that Lewontin’s fraud has been debunked, don’t you?

    http://www.humanbiologicaldiversity.com/articles/Edwards%2c%20A.W.F.%20%22Human%20genetic%20diversity-%20Lewontin%27s%20fallacy.%22%20BioEssays%2025%20%282003%29.pdf

    • Posted March 3, 2012 at 2:41 pm | Permalink

      The fact that most genetic variation occurs within populations rather than between then is not based on Lewontin, but on the fact that peer-reviewed, scientific studies analyzing over 600k SNPs and almost 300 STRs show that this is the case.

      Rosenberg, N. A. et al. (2002). Genetic structure of human populations. Science 298, 2381–2385.
      Li, J. Z. et al. (2008). Worldwide human relationships inferred from genome-wide patterns of variation. Science 319, 1100–1104.

  61. Galtonian
    Posted March 3, 2012 at 11:40 pm | Permalink

    RACISM is the belief that there are innate differences between racial groups on traits other than merely superficial traits such as skin color, facial features, and hair texture.

    Cognitive ability differences:
    East Asians (Han Chinese, Koreans, and Japanese) tend to have higher math ability and higher IQs than Whites who tend to have higher math ability and higher IQs than Blacks. This is an empirical fact that anyone can validate by accessing test score data from hundreds of datasets (with any dataset that includes racial population group samples with reasonably large numbers there are essentially no exceptions). Math ability and IQ type intelligence (g-factor) are both highly heritable and are influenced by the same gene alleles (what Professor Robert Plomin calls “generalist genes for g”), this has been shown by numerous studies by experts such as Ian Deary, J.C. DeFries, and others. A RACIST is someone who thinks that East Asians tend to be better at math and tend to have higher IQs than Blacks because of innate genetic differences rather than cultural differences.

    Sprinting speed differences:
    Blacks (especially West African Blacks) tend to be the fastest sprinters, next come Whites and then come East Asians. A RACIST is someone who thinks that East Asians tend to be slower sprinters than Blacks because of innate genetic differences rather than cultural differences.

    Sexual dimorphism differences:
    Black males tend to be more muscular and have larger penises than Whites who in turn tend to be more muscular and have larger penises than East Asians (if you doubt this then just spend some time on some free porn sites such as pornhub.com, within less than an hour of research of comparing Japanese male porn stars with Black and White male porn stars you will certainly agree). A RACIST is someone who thinks that East Asians tend to be less muscular and have smaller penises than Blacks because of innate genetic differences rather than cultural differences.

    Who now would ever believe that differences in human traits such as math ability, intelligence, sprinting ability, and body build and penis size would have anything to do with innate genetic differences rather than cultural differences??? A RACIST, THAT IS WHO WOULD BE STUPID ENOUGH TO BELIEVE SUCH RIDICULOUS NOTIONS!!!

  62. Torbjörn Larsson, OM
    Posted March 4, 2012 at 9:43 am | Permalink

    Since I am no biologist, and this is a nontrivial issue (since biologists comes down on different sides), I will go with the consensus.

    • Mike Pearlstein
      Posted March 5, 2012 at 3:03 am | Permalink

      @ Torbjorn Larsson,

      There is no consensus. In fact it even depends where you ask the scientists. For example, China and Poland IIRC are more likely to use race compared to the US.

      Also, see Sesardic* who mentions the wordplay used which actually means the same thing as race (there is an interesting example of AWF Edwards & Cavalli-Sforza).

      Race: A Social Destruction of a Biological Concept, Biology and Philosophy 25 (2010), 143-162.

      http://www.ln.edu.hk/philoso/staff/sesardic/getfile.php?file=Race.pdf

  63. herb fawcett
    Posted March 13, 2012 at 9:15 pm | Permalink

    While walking the light spectrum, I did have difficulty determining where orange and yellow differentiated, but there was no question of the difference between the red and blue ends of the continuum.

  64. Posted September 10, 2012 at 8:41 am | Permalink

    There are noticeable stereotypical distinctions of phenotypic characteristics of human populations related to different population regions of the world. There’s a general consistency of human phenotypic characteristics distinguishing particular regions/region from other regions/region.
    General descriptive phenotypic characterizations is what we’re talking about.
    The differences are clear enough to ‘non-scientists’.

  65. Posted October 20, 2012 at 11:46 pm | Permalink

    Reblogged this on Nomad Forgotten.

  66. Posted December 22, 2012 at 9:15 am | Permalink

    http://www.euvolution.com/neoeugenics/human_differences.htm

    [...]Sarich and Mield then address Gould’s race-does-not-exist mantra: “The basic reason Gould gives for his no-race position is this: ‘Homo sapiens is a young species, its division into races even more recent. This historical context has not supplied enough time for the evolution of substantial differences.’ (This from the man famous for his theory [with Niles Eldridge] of punctuated equilibria.)” They then go on to explain why Gould is wrong.

    They looked at differences between human races, between males and females, and differences between primates—particularly chimpanzees and gorillas.
    ** What is astounding is that there is greater morphological distance between human races than there are between the two chimpanzee species or between gorilla species/subspecies. **

    That is, the differences between human Races are Real, they are Substantial, and they did not take millions of years to diverge. Humans, rapidly occupying every available niche after leaving Africa 50,000 years ago, has been under enormous pressure to adapt. To do this meant selection for morphological, pharmacogenetic, behavioral, and cognitive traits. Not only are there many human races, but there are at least as many races as there are ecological niches, and only humans can create their own niches with forethought. What this means is not only Are there human Races, but humans have evolved uniquely to alter there own cultures or ecologies, further increasing unique selection pressures….

    Sarich and Miele explain: “Molecular data suggest that the two chimpanzee lineages separated around 1.5 million years ago; the comparable human figure is on the order of 15,000 years. In other words, the two chimp lineages are 100-fold older, yet show the same amount of variation. That is a remarkable result, the implications of which take a while to sink in. The implications follow this logic: Human races are very strongly marked morphologically; human races are very young; so much variation developing in so short a period of time implies, indeed almost certainly requires, functionality; there is no good reason to think that behavior should somehow be exempt from this pattern of functional variability. [...….]

  67. Johnathan Campbell
    Posted May 29, 2013 at 4:07 pm | Permalink

    One easy to measure ability that is vastly different in humans is the West African sprinting speed. This is found in that 81/84 of the sub 10 second 100m have been by men of west African origin.

  68. Posted March 9, 2014 at 12:19 pm | Permalink

    Why Kenyans Make Such Great Runners: A Story of Genes and Cultures – Max Fisher – The Atlantic

    “…It turns out that Kenyans’ success may be Innate. Two separate, European-led studies in a small region in western Kenya, which produces most of the race-winners, found that young men there could, with only a few months training, reliably outperform some of the West’s best professional runners.

    In other words, they appeared to have a Physical advantage that is common to their community, making it probably genetic.
    The studies found significant differences in body mass index and bone structure between the Western pros and the Kenyan amateurs who had bested them. The studied Kenyans had Less mass for their height, Longer legs, Shorter torsos, and more Slender limbs. One of the researchers described the Kenyan physical differences as “bird-like,” noting that these traits would make them more efficient runners, especially over long distances.

    Racial politics can make the genetics of African athleticism difficult to talk about in the West. Surprisingly, Western popular writing about Kenyans’ running success seems to focus less on these genetic distinctions and more on cultural differences. For years, the cultural argument has been that Kenyans become great runners because they often run several miles to and from school every day. But, about a decade ago, someone started asking actual Kenyans if this was true, and it turned out to be a merely a product of Western imaginations:…”

  69. Posted June 19, 2014 at 10:34 am | Permalink

    There are human races in human perception, no doubt, just as there are dog breeds in human perception. So I wonder if not really the concept of applying the new panacea, the genetic yardstick, to each and every human question today is the folly? In the olden days it was divination over bird’s entrails, now it’s genes. By now we know that epigenetics play an equal if not greater role and we still have to figure out what about 98% of “non-expressive” gene material is all about. The more I study this I wonder if this route of enquiry will not soon be discredited as phrenology once became, and almost over night.


21 Trackbacks/Pingbacks

  1. [...] http://whyevolutionistrue.wordpress.com/2012/02/28/are-there-human-races/ Like this:LikeBe the first to like this post. [...]

  2. [...] I spoke about a book about race. Here Jerry Coyne weighs in and makes a lot of sense to me. Like this:LikeBe the first to like this [...]

  3. [...] on the ‘race question’ I thought it would be useful to point to Jerry Coyne’s ‘Are there human races’?. The utility is that Coyne’s book Speciation strongly shaped my own perceptions. I knew the [...]

  4. [...] on the ‘race question’ I thought it would be useful to point to Jerry Coyne’s ‘Are there human races’?. The utility is that Coyne’s book Speciation strongly shaped my own perceptions. I knew the [...]

  5. [...] Again, I am not sure how new these articles would be to those invested in the sub-field. But they are must-reads for people in other parts of anthropology, adjacent social sciences, and really should be read by people like Jerry Coyne. [...]

  6. [...] Coyne, an evolutionary biologist at the University of Chicago, disagreed and said so: Well, if that’s the consensus, I am an outlier.  I do think that human races exist in the sense [...]

  7. [...] evolutionary biologist Jerry Coyne, who possesses impeccable liberal and anti-racist credentials, took umbrage at the review. ‘If that’s the consensus’, he snorted, then ‘I am an [...]

  8. [...] S.F.’s parrots join flight to the suburbs Why It’s So Important to Keep Moving Six-Legged Giant Finds Secret Hideaway, Hides for 80 Years Are there human races? [...]

  9. [...] Race Here is more discussion about “does the concept of race make sense”; here Puff the Mutant Dragon critiques some of what Jerry Coyne said. [...]

  10. [...] of two recent anthropological books declaring race a null concept biologically, much to the surprise of biologists, forcing the two views into [...]

  11. [...] Jerry Coyne si spinge oltre, chiedendosi cosa sia una razza. Da un punto di vista biologico è una variante locale di una specie. Ebbene quel 20% di differenze che esistono tra gli esseri umani e che sono intrapopolazionali sono sufficienti per identificare delle varianti locali. Come le chiamiamo? Se fossimo di fronte a una normale specie animale, la chiameremmo razza. Se fosse un vegetale potrebbe essere chiamato cultivar. Nella nostra specie invece il termine razza è bandito. Ma attenzione. Stiamo facendo una scelta etica, non biologica. La genetica moderna chiama le entità locali di Homo sapiens “gruppi etnici”. Il gruppo etnico non c’entra nulla con il vecchio concetto di razza, e neppure con le etnie che hanno originato molte guerre. Ma ricordiamo che da un punto di vista biologico le differenze tra razze, gruppi etnici, cultivar, sono molto labili. [...]

  12. [...] informed common sense on these matters is altogether admirable. For instance, he recently wrote a piece on human races that struck me as balanced and sensitive, but at the same time fearless in going where the science [...]

  13. [...] assiduity, actually reads my blog as well as Jerry Coyne’s) just told me that some time ago, Dr. Coyne had preceded me in writing about the biology of race, concluding in a single, lengthy blog pretty much the same as I had done in a series of three, and [...]

  14. [...] [...]

  15. [...] Pour approfondir la question, je vous conseille deux articles de wikipedia qui sont assez bien écris sur le sujet. Ce sont ceux en anglais pour Human genetic diversity: Lewontin’s fallacy et Race (human classification). Je vous conseille également la réponse apportée par Jerry Coyne (évolutioniste renommé à l’Université de Chicago): http://whyevolutionistrue.wordpress.com/2012/02/28/are-there-human-races/ [...]

  16. [...] Read the rest here. [...]

  17. […] For a non-crank evolutionary biologist who is willing to defend the race concept for humans, see Jerry Coyne. When you move away from the term “race,” then you obtain even more support from […]

  18. […] For a non-crank evolutionary biologist who is willing to defend the race concept for humans, see Jerry Coyne. When you move away from the term “race,” then you obtain even more support from […]

  19. […] For a non-crank evolutionary biologist who is willing to defend the race concept for humans, see Jerry Coyne. When you move away from the term “race,” then you obtain even more support from […]

  20. […] For a non-crank evolutionary biologist who is willing to defend the race concept for humans, see Jerry Coyne5. When you move away from the term race, then you obtain even more support from biologists for the […]

  21. […] http://whyevolutionistrue.wordpress.com/2012/02/28/are-there-human-races/, […]

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