And by “sensible,” of course, I mean a discussion that aligns with my own views. I’ve often written that while there are no finite and strongly genetically demarcated human “races”, there are meaningful and statistically diagnostic differences between populations, ethnic groups, or whatever you want to call them. This is in opposition to the common Left-wing view that races are purely “social constructs” having no biological reality.
Well, there aren’t a finite number of groups whose members are 100% genetically differentiated from other groups. But when you take all genes together, there are sufficient average frequency differences that one can discern statistical clusters that, in turn, allow you to use lots of genes to pretty much diagnose where somebody’s from and who their ancestors were. These “statistical clusters” are real, not social constructs, for they fall out regardless of the politics or biases of the investigator.
Recognizing their existence by no means justifies bigotry or stereotyping, but we shouldn’t dismiss the existence of those clusters simply because, in the past, people with an incorrect idea of “race” have used differences to justify segregation and prejudice. Yet all too often, as with genetic differences among ethnic groups, behavioral differences between the sexes, and evolutionary psychology, those on the Left simply dismiss entire fields because of a fear that scientific research will justify discrimination. And in theory it could, as it did in the past, but it’s better to know the facts and at the same time absorb the idea that the moral and legal equality of all humans, and the equality of opportunity they deserve, does not depend on evolutionary or genetic details. For if it did, then scientific findings could be used to justify prejudice—something that all humanists reject. Asserting that entire fields, like genetic analysis of human ethnic groups, are simply parsing “social constructs” is a form of anti-intellectualism that will stifle scientific progress. If some Leftists had their way, for instance, there would be no evolutionary psychology, no attempt to understand the evolutionary roots of modern human behavior. Do we really want to impose a moratorium on such work?
The recognition of genetic clusters as meaningful entities is the point that David Reich makes in the article given below. Reich, as you may know, is an accomplished professor of genetics at Harvard who’s done a lot of work on DNA-based human and primate phylogenies, human disease genes, interbreeding among ancient lineages of hominins (e.g., Denisovans, Neanderthals, etc.), and mapping human ancestry by looking at statistical grouping. (There’s a big NYT article about his work here.)
I highly recommend you read his essay in the New York Times‘s Sunday Review (click on screenshot):
I’ll give just two quotes from Reich: one about the scientific data and the other about its moral implications—or lack thereof. But read the article!
The data:
[After the 1972 paper of my advisor Dick Lewontin], a consensus was established that among human populations there are no differences large enough to support the concept of “biological race.” Instead, it was argued, race is a “social construct,” a way of categorizing people that changes over time and across countries.
It is true that race is a social construct. It is also true, as Dr. Lewontin wrote, that human populations “are remarkably similar to each other” from a genetic point of view.
But over the years this consensus has morphed, seemingly without questioning, into an orthodoxy. The orthodoxy maintains that the average genetic differences among people grouped according to today’s racial terms are so trivial when it comes to any meaningful biological traits that those differences can be ignored.
The orthodoxy goes further, holding that we should be anxious about any research into genetic differences among populations. The concern is that such research, no matter how well-intentioned, is located on a slippery slope that leads to the kinds of pseudoscientific arguments about biological difference that were used in the past to try to justify the slave trade, the eugenics movement and the Nazis’ murder of six million Jews.
I have deep sympathy for the concern that genetic discoveries could be misused to justify racism. But as a geneticist I also know that it is simply no longer possible to ignore average genetic differences among “races.”
Groundbreaking advances in DNA sequencing technology have been made over the last two decades. These advances enable us to measure with exquisite accuracy what fraction of an individual’s genetic ancestry traces back to, say, West Africa 500 years ago — before the mixing in the Americas of the West African and European gene pools that were almost completely isolated for the last 70,000 years. With the help of these tools, we are learning that while race may be a social construct, differences in genetic ancestry that happen to correlate to many of today’s racial constructs are real.
Recent genetic studies have demonstrated differences across populations not just in the genetic determinants of simple traits such as skin color, but also in more complex traits like bodily dimensions and susceptibility to diseases. For example, we now know that genetic factors help explain why northern Europeans are taller on average than southern Europeans, why multiple sclerosis is more common in European-Americans than in African-Americans, and why the reverse is true for end-stage kidney disease.
I am worried that well-meaning people who deny the possibility of substantial biological differences among human populations are digging themselves into an indefensible position, one that will not survive the onslaught of science. I am also worried that whatever discoveries are made — and we truly have no idea yet what they will be — will be cited as “scientific proof” that racist prejudices and agendas have been correct all along, and that those well-meaning people will not understand the science well enough to push back against these claims.
And how we should handle the future discoveries of genetics:
For me, a natural response to the challenge is to learn from the example of the biological differences that exist between males and females. The differences between the sexes are far more profound than those that exist among human populations, reflecting more than 100 million years of evolution and adaptation. Males and females differ by huge tracts of genetic material — a Y chromosome that males have and that females don’t, and a second X chromosome that females have and males don’t. [JAC: I find this statement somewhat misleading, because he’s talking about “biological” differences, not differences in genetic content, and the Y chromosome doesn’t have many genes.]
Most everyone accepts that the biological differences between males and females are profound [JAC: Again, it’s not clear what he means by “profound,” but I’d agree that they are there and that they do explain differences between the sexes in both morphology and behavior.] In addition to anatomical differences, men and women exhibit average differences in size and physical strength. (There are also average differences in temperament and behavior, though there are important unresolved questions about the extent to which these differences are influenced by social expectations and upbringing.)
How do we accommodate the biological differences between men and women? I think the answer is obvious: We should both recognize that genetic differences between males and females exist and we should accord each sex the same freedoms and opportunities regardless of those differences.
It is clear from the inequities that persist between women and men in our society that fulfilling these aspirations in practice is a challenge. Yet conceptually it is straightforward. And if this is the case with men and women, then it is surely the case with whatever differences we may find among human populations, the great majority of which will be far less profound.
An abiding challenge for our civilization is to treat each human being as an individual and to empower all people, regardless of what hand they are dealt from the deck of life. Compared with the enormous differences that exist among individuals, differences among populations are on average many times smaller, so it should be only a modest challenge to accommodate a reality in which the average genetic contributions to human traits differ.
It is important to face whatever science will reveal without prejudging the outcome and with the confidence that we can be mature enough to handle any findings. Arguing that no substantial differences among human populations are possible will only invite the racist misuse of genetics that we wish to avoid.
Between the unwarranted pseudoscientific statements of Nicholas Wade and James Watson on one hand (both criticized in Reich’s article) and the genetic blank-slateism of various ideologically-biased scientists and cultural anthropologists (who don’t act like scientists) on the other, lies the reasonable position—the one limned by Reich.
Greg’s Take on Reich’s Article
by Greg Mayer
I also like Reich’s article, but if he hopes to be able to talk about genetic differentiation, he’s going to have to stop accepting the “race is a social construction” fallacy, because that means everyone who thinks race is a social construction, or been convinced it is because they keep getting told it is, will ignore everything else he says. As he points out, there is measurable genetic variation; that that variation can be important (clinically, cognitively, etc.); and that that variation allows the identification of the geographic origin of individuals– and the latter is what race means. (As always, I use the zoological definition of a geographic race or subspecies. Subspecies may be described when it is the case that if you show me a specimen I can tell you where it is from, and, conversely, if you tell me where it is from I can tell you what it looks like.) The mass of genetic data on humans now allows us to divide indigenous populations (i.e. pre-Columbian) into so many races that fit the zoological definition of a race that one of the chief arguments against recognizing races is that there are too many recognizable races– 23 and Me is selling microracial identification on television! Very fine scale genetic data make recognition of geographic groupings so easy that the problem with subspecies isn’t that you can’t tell them apart, but rather you can tell everything apart, even local populations. Nomenclaturally, subspecies are optional, and there could be reasons, both practical and social, not to name them.
Reich cites Dick Lewontin‘s 1972 apportionment of diversity finding (which, of course, is true), but then doesn’t mention (or perhaps even realize) that that finding says nothing about whether there are recognizable races. What Reich does do, although more indirectly than I would, is to argue that human moral equality must not rest upon an empirical finding of no genetic differences, because then the finding of genetic differences will undermine the argument for moral equality. I 100% endorse him on the principle that human moral equality should NOT depend on an empirical argument about genetic differentiation. The problem with basing human moral and civil equality on empirical claims about human biological similarity is that such claims may prove to be mistaken. Tony Edwards, in his commentary on Dick’s 1972 paper, says it quite nicely:
“But it is a dangerous mistake to premise the moral equality of human beings on biological similarity because dissimilarity, once revealed, then becomes an argument for moral inequality.”
[Also, Reich seems terribly naive if he thinks “Most everyone accepts that the biological differences between males and females are profound.” I predict he will be assailed from the left on this point. And, Jerry and I wrote our commentaries independently of one another.]
h/t: Rodney, Greg
“… regardless of what hand they are dealt from the deck of life.”
Reich’s phrase seems a particularly bad choice here. It seems to imply that being born a member of some race might put them at an initial disadvantage.
Not a bad choice of words. We are dealt many different hands, many sets of cards from nature, our biological inheritance. Only some, among all of the sets very few actually, are about race.
I thought it was good because to me it recognizes the difficulties or otherwise of all sorts of things – income, intelligence, parenting, education, health, genes, genetic predispositions, how well you’re fed before and after birth, environment, societal conditions, etc.
I assumed by “hand” he was only referring to the genetic component. If he meant family income, location, etc. then I it was a reasonable choice of words. It was a small thing anyway. It just struck me the wrong way when reading it from the excerpt.
“It seems to imply that being born a member of some race might put them at an initial disadvantage.”
Being born a member of some race might indeed put a person at an initial disadvantage: vulnerability to racism.
But that is not what you meant. I think you were referring to genome differences that might not contribute to fitness in modern industrial, urban societies.
I have worked in over 15 countries with people of what others might say are a dozen races, in North, Central and South America, North, West and East Africa, the Near East, Middle East, South Asia and Southeast Asia.
My experience in graduate school prepared me for working with people of different races because my roommate in a university dorm for graduate students was from a small village in Cote d’Ívoire. He was the son of his father’s sixth wife. He won a state scholarship to attend a Lycee and another to study abroad.
When he visited Laval University in Quebec, the Quebeckers were awed by his command of French, his second language. He had already impressed us with his command of English, his third language. It did not seem to matter what the subject, politics, history, philosophy, he had the words and could debate the ideas in both French and English. He was as black as Nat King Cole and as handsome and well-mannered. So he impressed the women more than than men.
I accept that there are genetic differences between me and those people I worked with because I have studied the History and Geography of Human Genes by Luigi Luca Cavalli-Sforza, Paolo Menozzi, and Alberto Piazza. And I assisted my wife when she did her courses in genetics, bioinformatics and human evolution. Around that time I obtained my own entire mtDNA genome(a little over 64K base pairs) and 37 markers for Y-DNA (about 50 million base pairs).
Here is my take about how race is defined and how the technology informs the debate about whether or not human races are real.
The empirical data for defining races from DNA is based entirely on those base pairs that have no known biological function. (Non-coding = not part of a functioning gene = not associated with enzyme production.)
Primates belonging to the Haplorrhini suborder, including humans, have lost the ability to synthesize vitamin C (Taylor, 2008). No gene such as that for vitamin C varies among humans. I suggest that there is no human genetic trait worldwide that is not found among indigenous Africans.
The random non-coding mutations used to define race are not lost because they are not subject to natural selection: they offer no reproductive advantage or disadvantage.
My mtDNA genome (Western Ireland) differs little from the mtDNA genome of the Yoruba woman that anyone can access at the online depository.
How could coding sections of a 16K-long mtDNA genome differ by much, since almost all coding mutations would be fatal? Trivial variations in mtDNA are used to define genes.
So too with the Y-DNA. The mutations used to define racial differences are non-coding.
We can expect that genetic diseases might have different frequencies among men of different lineages, because at 50 million base pairs, the Y-chromosome is only one-third the size of the X-chromosome.
So if you got a defective gene from your mom and no compensating gene from your dad, you may be out of luck, compared to your sister who might have got what she needs from her mom.
The other 22 pairs of chromosomes are not much used to define race mainly because of cost. But if you are a Canadian Metis, mixed Amerind and European descent, you could in theory learn more about your ancestry by paying for an analysis of markers on the non-sex nuclear chromosomes. But these too may be non-coding.
As I understand the technology, we do not have the power to say that racial differences are not entirely based on non-coding sections of both the mtDNA and the nuclear genome.
If true, that would mean no functional differences in genotype or phenotype contribute to the classification of humans into races.
In turn, that means “race” as applied to humans remains in the eye of the beholder, or in the mind as part of the persons world view.
I am an atheistic materialist, In my opinion, the technology and evidence based on that technology is insufficient to support the view that human racial differences are based on variations in the genome of various lineages.
I don’t deny that human races may be real, only that the science does not support the claim.
Sorry, “Trivial variations in mtDNA are used to define genes.”
Should read, “Trivial variations in mtDNA are used to define races.”
“The empirical data for defining races from DNA is based entirely on those base pairs that have no known biological function.”
More or less, I think, dunno about the selection bias in SNP’s. But if random less than ~ 5 % should be under selection (in mice). Good point!
I always liked Luigi Cavalli-Sforza’s take:
Of course there obviously are clustered genetic differences, but you can just as well argue for two, three or four human races, as for 100 or for 10.000 ones. The race concept is difficult to pin down (this is not literal citation, but is what I gathered from him). In that sense ‘race’ is a ‘social construct’, but only in that sense.
Indeed, we already have problems with the ‘species’ concept, as illustrated by many posts on this very website, how much more difficult the ‘race’ concept is? But there still are ‘clustered genetic differences’.
“But there still are ‘clustered genetic differences.”
Agreed. But we do not (yet)know what functional differences are expressed in human organisms because races are not defined by regions of the genome that code for functioning genes.
Races are defined by the so-called “junk DNA”.
Races may be real, but we do not know yet if that is so.
The problem of entities being real or merely social constructs is dealt with by the philosophers Nancy Cartwright and Ian Hacking, both entity realists. (Both appear to draw on Michel Foucault.)
Hacking has said that biology has displaced physics as the Queen of the Sciences.
https://www.scientificamerican.com/article/kuhn/
Hacking’s book, The Social Construction of What? (2000) is a good introduction to entity realism.
To give a taste, I came to entity realism by accepting that a tree I bumped into was real. But I wondered if there is such an entity as a “forest” and from there I pondered the reality of entities defined by forest ecologists.
Even so, I enjoyed the film Avatar as a fantasy. And now I wonder how much of our science will seem to be fantasy a generation or so hence.
For some reason other species have races, but humans are an exception, according to the “no human races” folk. No explanation is given for how our species avoided evolutionary mechanisms such as founder effects and other forms of neutral drift during the various human diasporas and periods of allopatry among populations.
Not sure that’s a knockdown argument. I believe the same evolutionary mechanisms are at play in speciation, yet while most genuses have many, the genus Homo contains but one extant species: Homo sapiens.
I’m not disputing your underlying point, merely the logic with which you apply it.
Many genera are monotypic, or at least are monotypic with respect to extant species. It’s important to remember that the delineation of species groups into genera are substantially subjective. Based on percent similarity of DNA, the species in the genera Pan (chimpanzees) and Homo could be interpreted as belonging to the same genus, if we applied a species concept that used DNA similarity instead of the Biological Species Concept.
Exactly. No two people are equal, except insofar as we agree to treat them as such, morally and legally, and there is no good argument for doing otherwise. To my mind, that’s the Enlightenment in a nutshell.
+1.
Well put.
In a sense it’s moral equality that is a “social construct”.
I too liked Reich’s essay, and I’m really looking forward to his upcoming book. As someone who taught undergraduate genetics and evolution courses for 35+years, I’m well aware of both the data (from Lewontin and Cavlli-Sforza onward) and the difficulties many students have wrestling with both the data and its implications. A big problem, I think, is that historically the term “race” has been used to describe a social construct, and that construct has been used to justify ideas like eugenics, Jim Crow and the like. Indeed, in the era in which I grew up (the 1950’s, and in New England) the “touch of the tarbrush” definition of the “negro race” was pervasive. That, of course, is not at all consistent with the genetics of human population differentiation, even based on what was known about it at the time. Nevertheless, I am sorry to say, the legacy of those sorts of definitions of race remains. Thus, as biologists, we need to be very precise (as Reich is) in how we discuss the subject of human genetic variation, especially when it comes to classification of populations.
I agree. As is the case with Physics, most people have a 19th century (if that) understanding of genetics and human phenotypic variation. I think the notion that what most people mean by “race” is a social or cultural construct is still valid. And probably will be for a long time.
Agreed.
It is areas like this where I most disagree with Philip Kitcher’s proposals for “science in a democratic society”.
He and others claim that because we live in a racist society we basically cannot “give the racists any ammo” – and the people likely to be affected should veto (if they wish).
However, this ignores the science/technology distinction: it would, as the article points out implicitly, allow the fixing of some of the effects of racism.
He’s lucky his father and grandfather weren’t named David Reich, too.
😉
Heheh
Hope his nickname wasn’t “Thousand-year.”
“ because he’s talking about “biological” differences, not differences in genetic content”
I don’t understand this. Don’t biological differences arise from genetic differences?
Not really, for all differences between humans are in a sense biological, but not all of them devolve from their genes. What I was getting at is that the many differences we see between men and women don’t reflect a huge difference in their genetic nature: it reflect the differential activation of basically the same panoply of genes in men and women by the sex chromosomes.
Thanks. Also like the different life stages of, for example, the frog. They all share the same genome which gives rise to different phenotypes.
Is Dr. Coyne’s response essentially that genes may be similar, but which ones express themselves will vary whether it’s X or Y chromomsomes doing the activations?
(I don’t have a science background, so am careful how I interpret.)
The X/Y is not “doing” the activation as much as that they – and maternal hormone factors introduced into the egg – orchestrate details of development and later function in terms of activation. It is a multi-step machinery.
“The orthodoxy goes further, holding that we should be anxious about any research into genetic differences among populations.”
I’m confused about his use of “differences among populations.” Shouldn’t it be “differences between populations”?
I’m also confused about the placement of a question mark in reference to a quote that I’m asking a question about. I think the rule is that the question mark should be inside the quotation but that makes the quotation itself into a question. So I put it outside.
Biologists, who have all learned the analysis of variance (anova) in their statistics classes, use the terminology from anova, where “among groups” is the general phrase for when there are more than two groups being compared. When there are only two groups being compared, you can say “between groups”, but “among groups” would be still be acceptable.
GCM
I see. Thanks.
Also, in the US, punctuation goes inside the quotes; in the UK it goes outside. Not sure about Canada and everywhere else. I do it the US way because that’s where I live and how I was taught, but the other way makes more sense.
I only put something within quotation marks if it’s in the original quoted text, otherwise, it’s outside. I’ve heard this referred to as “Oxford style”, which I guess has something to do with the house style of Oxford University Press, but I’m not sure. (I’m US born, never visited the UK.)
GCM
I thought Oxford style had something to do with shirts.
I have trouble understanding why race isn’t BOTH a social construct AND genetic. If we can analyze DNA and find differences that correlate to specific populations and at the same see that a society’s concept of who is or is not a member of a racial group is different than another society’s concept, not to mention that it can differ within a society over time. Perhaps I’m missing something, but it seems to me that these are not mutually exclusive, even if the majority of people will tolerate one and not the other.
I’d suggest that social races are a social construct based on, but not necessarily mapping directly, on biological demes.
Social races also import social meanings as part of their definition and can be used in a socially discriminatory way.
Biological demes can also be used in a discriminatory way to (say) customise medical and dietary advice.
Hence the confusion and therefore fear of misuse.
There are, of course, genetic differences in populations. But deciding which of those differences – and in what amount – they will be used to place a person in a man-made category requires construction. In the U.S. census, an ethnic Baluchi born in Iran would be considered Caucasian, while his Pakistan-born brother would be labeled Asian. Jews, Irish, Spaniards, Italians, and Finns have all been labeled white or not white depending on who was deciding and when.
I think thats the heart of it, so much discussion of race is fixed to US-normative definitions which are themselves bureaucraticly defined, and for historical socio-political reasons.
They don’t make sense, and most people would disagree with them (how many people see Icelanders and Iranians as the same race, or Japanese and Punjabis?), but they stick with the terminology and that defines the discussion.
Hell even ‘ethnicity’ has been subverted to this, peep’s just replace race with the word ethnicity.
Twenty Three and Me can not only tell me if I have African ancestry, but also how much Scottish, Swedish and Italian. Race may be a social construct like gold finches and house finches or chimps and bonobos. But it’s genetically real.
Here is some additional reading: https://notpoliticallycorrect.me/
Among almost 600 comments, a few dozen have become “editor picks” in the New York Times, here is one of them:
“Oliver Herfort Lebanon, NH 8 hours ago
The concept of race has no scientific basis and will never have. It is solely a social construct that originated hundreds of years before humanity had any idea about genetics and the DNA genetic code. In order to avoid exploitation of natural genetic differences between originally geographically separated populations as pseudoscientific proof of racial differences, science has to abandon the term race all together.
We have useful alternatives like talking about genetic population variance. The diversity of the genetic pool is essential to human survival. We have no idea yet which genetic variation will be beneficial in the future.
Also never before in history have originally geographically distinct populations exchanged genes so frequently. With these dynamics external criteria and surrogates like skin color will be less helpful to determine susceptibility of a human to certain diseases. We will go right to the genetic code to calculate individual risk for prostate cancer, multiple sclerosis, diabetes, hypertension and multiple other diseases.
Reply 72Recommend “
The comments section to the NYT piece show just how much this opinion needs to be published.
Also from the times https://www.nytimes.com/2018/03/20/science/david-reich-human-migrations.html?action=click&contentCollection=Opinion&module=RelatedCoverage®ion=EndOfArticle&pgtype=article
“although more indirectly than I would, is to argue that human moral equality must not rest upon an empirical finding of no genetic differences, because then the finding of genetic differences will undermine the argument for moral equality”
Reading through the article, it struck me that this is one of those cases where there’s an intersection between science and ethics, leaning more to the ethics side than the science. So we have science communicators arguing in-effect ethics in order to help the understanding of the related science.
I remain unconvinced by this argument, and I did not doubt genetic clustering before.
Suppose you can pinpoint quite exactly where someone is from by looking at their genes, and often enough by simply staring at their faces.
Now I come along and proclaim that there is neither one humanity, a handful of races, or countless ethnicities: humanity is in fact divided by the lunar and solar peoples. To demonstrate this “scientific fact”, I determine a genetic equator of sorts, a line that cuts across the genetic landscape such that the main clusters are neatly sorted to either side. Half of the people are solar, the other half are lunar. I would be able to look at someone’s genes, or often enough, their appearance, and tell them nicely to which group they belong. Does that make lunar and solar peoples real? This is the kind of problem I have with the race conception.
It looks to me that nobody cannot even agree on how many such races actually exist, and there are many locations where some line must be drawn; how tight and loose the circles around clusters are set.
How many races exist? Just the classic big three, or 38 as determined by population geneticist Cavalli-Sforza? For such reason, I believe “ethnicity” is a much better idea, and it’s not merely preference for a different word. It takes origin including genetic makeup, geographic location and isolation into account, but also recruits language, self-identity and culture into the consideration, which influenced over millenia which feathers flock together.
To answer your question, yes, what you describe does make lunar and solar people real. Just because genetics is messy doesn’t mean we can just ignore it in favor of ethnicity or some social definition of race. Of course, we use genetics to answer some questions and social grouping to answer others.
Exactly right! I did 23 N me DNA testing, and resulted that I’m 75% SE and 25% NE, I was born and educated in LA, mother tongue and culture is Spanish and LA, but also I’ve lived and retired in USA, so: what ethnicity Am I? Race? Does it really matters? No it doesn’t. I’m in agreement with P. ERLICH on this.
“Reich cites Dick Lewontin‘s 1972 apportionment of diversity finding (which, of course, is true)”
As always when Lewontin’s mathematical analysis of race comes up, I must note that his analysis is not mathematically valid. Using his method and measures, the within-group “diversity” divided by the total “diversity” could still be close to unity (supposedly indicating genetic homogeneity among groups) even if the groups shared no genes at all, if within-group “diversity” were high enough.
Without further analysis, Lewontin’s conclusion is invalid. It may still be true, but we should be using valid arguments to show this.
Lou–
Even if Lewontin’s analytic methods are incorrect, his conclusion is true, as affirmed by later studies. This paper, by Rosenberg et al., using Excoffier’s AMOVA, finds 94% of variation to be within populations (i.e. somewhat higher than Lewontin’s number, but the take home message is the same). Rosenberg et al. cite 5 other papers (see their refs. 5-9) coming to the same conclusion. They also cite Lewontin, because he was (at least among) the first to reach that conclusion. It is common to cite the first author of a finding, even if the details of their work have been superseded by further data and analyses; to a systematist, such as myself, it is crucial to do so. (And my apologies for not having properly followed up on the pdf’s you sent– this is a reminder to me to do so, and I’ll try 🙂 .)
GCM
Thanks Greg for your response. Rosenberg’s 2002 paper and Excoffier’s Structure both pre-date my papers pointing out the problem. Noah Rosenberg came to my talk at Stanford a few years ago and agreed with my assessment of the mathematical problem, though we did not talk about its relevance to humans.
In 2013 Rosenberg coauthored a more sophisticated paper on the subject, recognizing some of the mathematical problems of traditional approaches. He wrote “…our analysis suggests that many unusual observations of FST, including the relatively low FST values in high-diversity human populations from Africa and the
relatively low estimates of FST for microsatellites compared to SNPs, can be understood not as biological phenomena associated with different groups of populations or classes of markers but rather as consequences of the intrinsic mathematical dependence of FST on the properties of allele-frequency distributions.”
At that point he still did not seem to understand that there is a unique correct partitioning formula for any standard diversity measure into independent within- and between-group components (see my papers), but at least he recognized that the normal (incorect) way of partitioning diversity in pop gen could, for purely mathematical reasons, lead to wildly incorrect conclusions about the degree of differentiation between groups.
A very sensible article, and a lot of good comments.
The reason surely why some, such as Kitcher, are worried about science in this respect giving racists ‘ammo’ is that it is not so long ago that theories of racial ‘superiority’ and ‘inferiority’ were widely taken to be scientific, and not of course just in Nazi Germany, but throughout, in particular, the Anglo-Saxon world.
sub
Kenan Malik wrote an excellent book in 2008 on the subject of race: “Strange fruit. Why both sides are wrong in the race debate.” He shows e.g. how modern-day identity politics unwittingly rehashes old racist arguments. He also goes into depth about how race can be a social construct at the same time as one acknowledges that there may be genetic differences between different groups of people. See https://www.goodreads.com/book/show/3496693-strange-fruit
I commented too quickly, before I read the article. It really is a good article IMMO, worth reading. Thanks.
I had a GF of eclectic ancestry who did one of the tests. Part of her result came in with 1% Irish. She decided that was ‘residual’ me.
After reading the articles and comments, I would say that I am all in for replacing the social definition of race with its moral problems. I see two possibilities. The one I personally prefer is the breeder definition – in which case when the Neanderthal breed was assimilated we went all in mongrel. There is also the zoological definition of geographical race – in which case races are currently localized in areas of ~ 100 km diameter.
What I cannot agree with Reich is when he has mentioned medical implications and the moral problem of human sexual differentiation, and yet claim “substantial differences among human populations are possible”.
Modern human sexual differentiation is not great compared to other apes, yet the average mass difference between adult US males and females is 15 % [ https://en.wikipedia.org/wiki/Human_body_weight#Global_statistics ]. But when we look at the geographical variation, IIRC we find Lewontin’s 7 easily resolved geographical clusters by ADMIXTURE, or at the current resolution limit ~ 36,000 potential races explaining at most 1/100 times the variation in a principal component analysis (~ 0.1 %, see Figure 1 of https://www.nature.com/articles/nature07331.epdf ). Genetic differences maps poorly to biological species in that sense, you see better correlation by genetic distances. In which case human zoological species are ~ 1/10 (IIRC) as distinct as chimp species. Putatively then, genetic chimp species may cluster at 10 km distances. [Actually there is a discussion if the genetic distances to phylogenetic tree leaves could be used to help define prokaryote taxa supplementing cluster methods defining leaf OTUs in the first place.]
Finally, as Frederick points out, most variation is likely under drift. It is a diluted measure of “substantial” qualitative differences.
Well, to paraphrase Dick Lewontin somewhat, if God came to you in a dream and told you that you or someone else was a member of a particular race, what would you do next? In other words, how *useful* is the concept of race when applied to humans?
How useful is the concept of “black holes”? Sometimes intellectual understanding is sufficient. After all, the studies of genetic differences between ethnic groups has helped us not only trace the migration of our species, but identify our ancestry, as with 23 & me. You don’t necessarily have to use the word ‘race’, but the recognition that different populations have meaningful genetic differences (see Reich’s piece in last week’s NYT) has been meaningful, and some of those genetic differences correlated with “self reported race.”
I liked the Reich article. But note that he never uses the words “clustering”, unlike Jerry. Was that intentional?
My understanding was that an “isolation by distance” model is a pretty good first-order approximation for ancient human populations (before trade/globalization). If that model is good, then the genetic map (where each person gets a point, and pairwise distance = genetic distance) should roughly equal the geographic map (distance = geographic distance over land). PCA projections often seem to justify it. Since (If) ancient populations are roughly uniformly distributed (not clustered) on the globe, I wouldn’t expect much genetic clustering either. (where “clustering” = areas with a high density of points). You couldn’t divide the ancient global population into “races”, there is only a smooth continuum of points.
But, if during globalization you make a new population composed of two groups of people taken from opposite ends of the globe (eg, europeans and west africans, in america), I would agree the combined population will have two clusters. Then perhaps it makes sense to define “races”, but these are local quirks of the process of globalization, rather than natural biological entities. And if not too much genetic mixing has occurred yet, the genetic map would still reflect the ancient population map, which has no races.
Does that make any sense?