Central Asian ethnic groups are more defined by societal rules than ancestry. Researchers writing in the open access journal BMC Genetics found that overall there are more genetic differences within ethnic groups than between them, indicating that separate ‘ethnic groups’ exist in the mind more than the blood.

Evelyne Heyer, from the Musée de l’Homme in Paris, France, led an international team of researchers who studied mitochondrial DNA and Y chromosome data from several populations of two major language ethnic groups of Central Asia, the Turkic and Indo-Iranian groups.

She said: “Our results indicate that, for at least two of the Turkic groups in Central Asia, ethnicity is a constructed social system maintaining genetic boundaries with other groups, rather than being the outcome of common genetic ancestry.”


The story is at Science Daily.

Hat tip Stephanie

I’ll have more on this later

Comments

  1. #1 6EQUJ5
    September 2, 2009

    When I was in elementary school, there were three races of man. In junior high, there were four. In high school, there were five. Freshman year of college, there were twenty-three. Then I took a genetics course, and that as the end of that nonsense.

    Race is a useful concept in track and field, and in signal timing conditions, but that’s it.

  2. #2 Mr. Gunn
    September 2, 2009

    We really need a better word for “genetically-distinct populations”, so that the drug companies know what to do with personalized medicine results showing differences in drug responses among these genetically distinct populations (which just happen to have co-associating visible phenotypic differences and shared cultural backgrounds and so on).

  3. #3 CW
    September 2, 2009

    which just happen to have co-associating visible phenotypic differences and shared cultural backgrounds and so on

    Except when they don’t.

  4. #4 NewEnglandBob
    September 2, 2009

    Of course there ARE races, just ask Usain Bolt.

  5. #5 Alan Kellogg
    September 2, 2009

    What this study shows us is, absent any mechanism for separation populations of a species tend to blend where they come in contact. Where separation does occur you will get distinct genetic populations, but without that separation people will tend to be a mix of two or more populations.

    Today, with our fast and easy travel, no place can be said to be isolated; unless it’s a social isolation. In the past, when travel was harder and slower, more locations could be considered mostly isolated, and genetically distinct populations arose. The Khoi and Bushmen of southern Africa, the Nilotics of Ethiopia and Somalia, and the Aborigines of Australia are examples of groups that arose thanks to geographic isolation.

    What it comes down to is, races will arise among humans as with any other species so long as the conditions are right. But, when conditions are right races will mix, and that is the pattern we see today. At the moment race mixing is favored, but it need not continue.

    You get right down to it, the matter is not as clear cut as one would think. As with most matters human it is complex and on some levels complicated. Remember that you’re dealing with people and you’ll be ahead of the game.

  6. #6 Dan
    September 3, 2009

    How does that refute the view of clines being evidence for races? Or the fact that hap-maps overlay onto geographic grouping of populations? I’m not an expert here, but this study about immediately adjacent Turkish and Indo-Iranian groups, not more significantly separated groups.

    Anyway, glad to see Greg that you refrained from the “People who disagree with me are racists” BS.

  7. #7 toto
    September 3, 2009

    How does that refute the view of clines being evidence for races?

    “Races” imply discrete groups. Variation among humans is roughly continuous, though there are also some “bumps” that seem to match traditional divisions (Eurasians, East Asians, and Africans) – as well as obvious geographical obstacles (Sahara, Himalaya). On the other hand, where there are people who live between these rough groups, racial assumptions fail to hold. “Black” eastern Africans will be genetically closer to “white” southern Arabs than to “black” Nigerians, for obvious reasons (look at a map).

    At any rate, you can very well be a racist even with purely continuous genetic variations. Racists apply their theories to groups that have very different origins (e.g. West Africans vs. Europeans). In this case, you’re bound to find some correlated differences, as indicated by PCA graphs where Yoruba and people from Utah cluster very far from each other. Racists posit that these corelated differences are what makes Blacks more stupid than Whites, or Scandinavians more stupid than Mediterraneans – oops, sorry, wrong century.

  8. #8 Dan
    September 3, 2009

    “Races” imply discrete groups.

    No, I think that would be “species.” Hence the biological definition of species including reproductive isolation, and even that is not a hard line, as hybridization between species proves reproductive isolation is not always complete at that level.

    Who has ever said that races are discrete??

  9. #9 Dan
    September 3, 2009

    Oh, and of course you can be a racist whilst accepting clines as races. But what Greg has said in the past is that you cannot not be a racist accepting such a view.

    Insisting that “races are real” is a self fulfilling and overt racist act. So stop it now, please.

  10. #10 José
    September 3, 2009

    Who has ever said that races are discrete??

    That’s exactly how most people use race. What world do you live in?

  11. #11 Stephanie Z
    September 3, 2009

    The term “race” has an amazingly long history of being used in statements like, “It would be against the laws of God and Nature for any two such obviously separate groups to mix.”

  12. #12 Dan
    September 3, 2009

    José,
    I’m just going off the definition of species established by the modern synthesis in evolutionary biology and extrapolating it to mean that groupings below the species level are by definition not reproductively isolated.

  13. #13 Greg Laden
    September 3, 2009

    [5]Alan: I’d go a step farther…

    The ausralian aboriginies were not isolated. They occupied an entire continent and for a large portion of that time the northern shelf was exposed so Australia, New Guinea, etc. etc were all on one land mass. The Nilotics would not have been isolated in Ethiopia because they mostly live elsewhere, and they’ve been in close cultural contact with other people for a very long time. Also, from rock art and some other data, it is a reasonable guess that thir distribution at the time of, say British colonial conquest was recently extended (a bit) to the south, but has been contracted in many other aras (arid regions in the north).

    The Khoi/San/Ju’/hoansi Bushmen are also not isolated, but are part of a highly genetically diverse group that lived across a huge area at the time of Europeans arriving in southern African, and were actively contracting their range following a period of expanding their range. Bushman genes have been flowing into non-bushman populations through hypegyny, culturally different in operation but genetically similar, likely, to the situation with the pygmies.

    IN the case of Nilotic people and to some extent bushmen, any genetic isolation from surrounding areas is probably a cultural phenomenon caused by said groups themselves.

    The reason why it is easy to think of “Australian aboriginies” and “bushmen” as genetically distinct and well defined populations is because that is how they are represented in the research and on the charts.

    Similarity and variation for a given gene or part of the DNA sequence in humans is primarily explained by geography with a few sticking points such as oceans and mountains, just as expected, but with those biogeographical barriers being much less distinct than most people expect.

  14. #14 Greg Laden
    September 3, 2009

    Dan[6]: It does not refute the racist view of the human genome that you mention. It argues against it from the finer side of the scale, as presented.

    The Turkish and Indo-Iranians are not separated at all, really. Other than culturally.

    If you look at individual segments of the DNA you get nice clines, and clines themselves are not evidence supporting the racist model. They are evidence against the racist model. As I said in a comment above, and as you imply, simple distance is the best way to explain almost all genetic variation.

    [Did I use the word "racist" enough????? : ) ]

  15. #15 Greg Laden
    September 3, 2009

    Dan[8]: A “race” in biology is a “subspecies” meaning “almost species”

    Saying “who has ever said that races are discrete” is the funniest thing I’ve seen so far today. Of course, I got up late and am still on my first cup of coffee, so that may not hold much longer.

  16. #16 Dan
    September 3, 2009

    Greg (aka Jackass),
    Dude, please I’m happy to find out where I’m mistaken, but you being a smartass isn’t helping.

    Of course I recognize that creationists and actual racists think races are discrete, I shouldn’t have implied otherwise. However I’m trying to understand from a biologist’s perspective, not a creationist’s. Who has claimed that races are discrete from a biologists perspective since Mayr, Dobzhansky, Simpson, et al.? Dawkins? Gould? Or some esoteric anthropologist that I’ve never heard of? I’m not being a smartass, I honestly would like to know, as I could then go and look up what I’m missing here and learn something.

    -Dan

  17. #17 Greg Laden
    September 3, 2009

    Dan[9]… We’ve had this conversation before. My personal preference is to use the word “racist” ad an adjective that describes things, idea, or people, with a race-based component or that reifies race, and races are defined and described as non-clinal, correlated allelic clusters with some kind of boundary. This sudden shift we see (from you specifically) that clines are proof of discontinuity, and that no one has ever claimed that races are discontinuous groups is … well, I’m struggling with the words (as in struggling to not say them).

    So anyway, yes, a model of human population genetics that supports or purports the idea of races is racist by the way I use the word.

    As you may recall if you carefully read everything I’ve written, I also strongly urge us to not assume that “racist” equals bad. Necessarily.

    Yes, I’m being sophistic here, but with people running around saying that “clines are races” somebody needs to be reminding everyone else that calling people who look different from you different sub species has consequences.

  18. #18 Greg Laden
    September 3, 2009

    Dan[12]: Ah, I see your problem. Here it is:

    No one using racist ideas today is making any reference whatsoever to the modern synthesis. No one in the 18th century, when debating the fate of the Indians in Spannish Territories used that concept (it did not exist yet). The Nazis and the Turks, in their holocausts, were clear on the distinction between races. Invading troops in the Congo today who kill Pygmies for sport and food are not claiming that there is a clinal connection, but rather, make a species level distinction. James Watson, in telling us that all the black people who ever worked for him were more stupid than all the white people who ever worked for him, was using a bounded race model.

    Racism is a very real and important thing, and it is underlain by a long history that has absolutely nothing to do with your strange and useless extrapolation.

    No one has said, to my knowledge, that races are reproductively isolated from one another (mechanistically or immunochemically). That is a suddenly constructed straw man you just invented, apparently.

  19. #19 Dan
    September 3, 2009

    Greg,
    Yes, we’ve had this conversation before, and I’m saying now, okay, you’re the expert. Please be patient and explain to me what I don’t seem to understand.

    I mean, when a student with a question visits you during office hours, do you just laugh and spit coffee in their face? Not cool.

    But at least now I get the beginning of an attempt to work with me.

    and races are defined and described as non-clinal, correlated allelic clusters with some kind of boundary

    Okay… but you last time had said that some anthropologists accept clines as races. Why do you think they accept that definition, and you don’t? (again, this would help me understand whether I’m more convinced by you or by “other anthro guys).

    As you may recall if you carefully read everything I’ve written, I also strongly urge us to not assume that “racist” equals bad. Necessarily.

    Okay, I haven’t read everything you’ve written, you called me there. ;-)

  20. #20 Greg Laden
    September 3, 2009

    but you last time had said that some anthropologists accept clines as races. Why do you think they accept that definition, and you don’t?

    A cline is a gradient, not a boundary. Accepting a cline as a race is like accepting distance as the town line. It makes no sense. If I said that I was drunk.

    Okay, I haven’t read everything you’ve written, you called me there. ;-)

    Well, get on it! Love your quote page on your blog, by the way.

  21. #21 Dan
    September 3, 2009

    Greg,
    Okay, I’m still not sure why races have to have a boundary, other than the observation that a clinal gradient necessitates a very blurry and incoherent definition of race (i.e. what happens to a group living in the middle of the gradient). Looking at it that way, I don’t find either view – races as clinal gradients or races as exclusively social constructs – as intellectually satisfying given observed human diversity.

    I’ll give it more thought.

    Also, thanks for the comment on my quote page!

    -Dan

  22. #22 tif
    September 4, 2009

    Dan [21]:

    Okay, I’m still not sure why races have to have a boundary, other than the observation that a clinal gradient necessitates a very blurry and incoherent definition of race (i.e. what happens to a group living in the middle of the gradient).

    I have a question, if you believe that genetic clinal gradients are the natural boundaries of the “races” (taking, for example, a North Africa-Europe gradient).

    1. How do you explain relatively larger genetic clinal gradients that run within the “races” (taking, for example, an East Africa-west Africa gradient)?

    2. How you explain populated areas where natural human migration has prevented this ancient genetic artifact -genetic gradients, from appearing (Such as “the Americas” or simple cities).

    3. Your “race model” (really just the same model from the 1800′s) seems to be flawed in that it doesn’t accurately reflect human genetic variation (neither in the past nor presently).

    Luckily we have a new model that seems to depict human genetic variation accurately by first discarding the old “race model” (3-4-5, or whatever # of “races”) and bringing in a temporal dimension…

    This model is simply the our current understanding of the migration of humans.

    http://channel.nationalgeographic.com/channel/human-family-tree
    https://genographic.nationalgeographic.com/genographic/globe.html
    http://www.bradshawfoundation.com/journey/
    http://www.youtube.com/watch?v=OV6A8oGtPc4 (1 of 13)

    This our most up to date knowledge of humans and their genetic variation. These links don’t cover recent migrations (for two examples: the colonization of the Americas, or diverse migration to world cities), nor do they cover African genetics as much as they should (just ask Sarah Tishkoff about this – http://www.sciencedaily.com/releases/2009/04/090430144524.htm). However there is just no need to cling to old models about “races” to try to explain human genetic variation, we are well past this stage…

    …Well according to that damned, PC, socialist Craig Venter, there are some scientists who are not past this mentality and they still try to fit old “race models” into genetics (http://www.youtube.com/watch?v=gPU5h679pSw)…

    Ah well, “c’est la vie.” We can all agree that time moves science forward, even past the old prejudices and bickering of the scientists themselves. It’s just that I’ll be glad when “race theory” is to the point where “Intelligent design” is now. Universally debunked.

    Oh BTW here are some more links dedicated to debunking the old “race models” that the 1800′s gave us:

    http://www.youtube.com/watch?v=1EyeNi6qsfs (1 of 3)
    http://www.pbs.org/race/000_General/000_00-Home.htm
    http://www.understandingrace.org/home.html

    Looking at it that way, I don’t find either view – races as clinal gradients or races as exclusively social constructs – as intellectually satisfying given observed human diversity.

    Race is a social construct (or more accurately a 1800′s social construct). Observed human diversity does not follow the “race model,” but societal rules dictate and construct all of the numerous “race models” (their are as many as your mind can allow).

  23. #23 tif
    September 4, 2009

    It appears that my comment has not cleared the spam filter yet. Yo Greg, can you expedite said comment?

  24. #24 Dan
    September 5, 2009

    tif,
    You again? Seriously, I’d like to discuss things, but someone who just gets in my face is someone who I just want to ignore.

    Greg,
    Thinking about the clinal gradient “blurring” of so-called boundaries between populations some more… I still can’t get around that because in most cases you’d expect to see a clinal gradient in the case of genetic drifting of a species over a geographical axis (East-West, out of an African origin), that your insistence on there having to be a boundary is bogus. Unless you find some indication of disruptive selection (which of course there isn’t any, I think), in which case of course there you have your clear boundary.

    I think that actually makes sense now that I’ve written it out and re-read it before clicking ‘Post.’ Is this common – that taxonomists look for some form of disruptive selection before calling two or more subgroups of a species ‘races’?

    Thanks again for taking the time to give some feedback.
    -Dan

  25. #25 tif
    September 5, 2009

    I love you too Dan. ;x

  26. #26 Greg Laden
    September 5, 2009

    you’d expect to see a clinal gradient in the case of genetic drifting of a species over a geographical axis (East-West, out of an African origin), that your insistence on there having to be a boundary is bogus.

    This makes as much sense as tits on a boar, dan. Let me use most of the same exact words and say it right, then you read that and go think about it.

    Because you’d expect to see a clinal gradient in the case of genetic drift across the geographical range of a population (such as East-West across eurasia or whatever out of an African origin), the insistence on there having to be races, which by definition are defined as having some kind of a boundary, is bogus.

  27. #27 Dan
    September 6, 2009

    Greg,
    You can read about as well as a boar apparently, and are incapable of anything more than a snappy comeback and a “No, that’s wrong.” Maybe I didn’t make myself clear, as I was commenting in a bit of train-of-thought trying to work this out. Let me try again.

    Because you’re looking for discontinuity, it seems like you’re insisting on there being some mechanism such as disruptive selection, if races exist. There is no such disruptive selection, ergo no races. I was saying, maybe not clearly enough, that come to think of it this makes a bit of sense. Is this common – that taxonomists look for some form of disruptive selection before calling two or more subgroups of a species ‘races’?

    Try thinking about what I’m saying so you can understand it, before replying next time.

    -Dan

  28. #28 Jim Thomerson
    September 7, 2009

    My impression is that animal taxonomists don’t use the term race much anymore, simply because it has become a charged word. I think we use the term population where we might have used race 50 years ago. One of the Pacific salmon has a two-year life cycle, so there are odd-year and even-year __________s. What word would you use to fill in the blank?

    At one time, there were formally described human subspecies, which no one seems to think today. There is an argument about whether subspecies are a good idea. One could describe a subspecies based on various counts or measurments being distributed in the required manner. Subspecies are generally geographically bounded entities within species, so one needs to know much more to properly describe a subspecies than to describe a species. One can legitimately describe a species based on a single individual. The anti argument is that subspecies described on variation of certain characters covers up the possible discordant variation of other characters.

  29. #29 Dan
    September 8, 2009

    Jim,
    Thanks, that makes sense (and helps me, anyway), even though I don’t know to what extent you can describe an entire species based on one individual.

  30. #30 Jim Thomerson
    September 8, 2009

    To describe a zoological species, you have to have a minimum of one individual, the Holotype, the name bearer. It is nice to have more members of the species, paratypes, to inform on variation within the species, but there is no formal requirement for same. (I have opened a jar of paratypes and found that some of them belonged to a different Genus.) The statement, “A species is what a competent taxonomist says it is.” is not one of Greg’s falsehoods. I’d guess that a majority, even today, of animal species have that, and little more, going for them. I’ve not described a species from a single specimen, but I have described several from a few individuals taken in a single collection. It is nice when later collections, particularly those made by others, support my conclusions.

  31. #31 Greg Laden
    September 8, 2009

    A jar of species? Well, since I’m more of a primatologist, it would be a barrel for me, I guess.

  32. #32 Dan
    September 9, 2009

    I’ve not described a species from a single specimen, but I have described several from a few individuals taken in a single collection.

    I’d say that makes a lot more sense than from a single individual, at least from what I understand, because a single individual is expected to vary from the type specimen (if you look closely enough).

    But I’m not a taxonomist nor a zoologist. ;-)