Discovery Institute makes hay of Dawkins tweet, and a geneticist mistakenly says that artificial selection won’t work in humans

February 20, 2020 • 9:45 am

Unless you’ve been in Ulan Bator (and actually, some people in Mongolia do read WEIT), you surely know about Dawkins’s latest twitter kerfuffle, in which he said, correctly, that human eugenics would “work”. That is true in the sense he meant it: artificial selection practiced on human traits would yield a change in mean trait values, for most traits have appreciable “heritability.” People misinterpreted that—most of them deliberately, I think—to excoriate Dawkins as favoring eugenics, something that’s clearly untrue, especially in light of his subsequent clarifications. It’s not clear to me why these people won’t admit that they mischaracterized Dawkins’s tweets. But of course people get stuck in their ideology and are loath to admit error.

[UPDATE: Dawkins reiterates what he meant on a comment on yesterday’s post: here.]

One commenter noted that most of the pushback seemed to come from the Left or from the woke. That may be true, for many of them hate Dawkins for being “the wrong kind of atheist”: seen (wrongly) as shrill and uncaring about oppression. But I have to note that the Right has been making hay about Dawkins’s tweet as well—especially the religious, who tend to be on the Right. That goes double for creationists, including those who are wasting their lives at the Discovery Institute.

And so, on the DI “Evolution News” website, David Klinghoffer, an Orthodox Jewish ID creationist, has evinced some glee about Richard’s tweet. To see it, click on the screenshot below (it goes to a Wayback Machine link that I’ve archived so that the site itself doesn’t get clicks):

Klinghoffer takes two approaches to denigrating Dawkins.

The first is to cite geneticist Dave Curtis’s recent Twitter thread arguing that eugenics wouldn’t work. (Curtis is an Honorary Professor in the Division of Biosciences at University College London.) Curtis’s tweets have cited widely to show that Dawkins was wrong, but, sadly, I think Curtis himself is wrong. Dead wrong. I’ll give a few of his tweets and briefly explain why.

Here’s the first one, and the assertion that “eugenics simply would not work” is not at all supported by human data, as I document below.

I’ve indented Curtis’s subsequent tweets (only the ones I see as relevant). My own comments are flush left.

I work on human genetics and am honorary professor at the UCL Genetics Institute. I’m the editor-in chief of a journal which used to be called Annals of Eugenics. I just wanted to say that we now know from the latest research that eugenics simply would not work.

This is not true at all. The up-to-date data we have suggests strongly that artificial selection on human traits would “work” in the sense of changing mean trait values in the direction you select. Moreover, it would work in this way for nearly all human traits (see paper below). By saying eugenics would “work”, of course, I am, along with Dawkins, not at all saying it should be practiced. While a limited form of selection in humans is acceptable—for example, preventing a couple who are carriers of a recessive genetic defect or disease from producing an offspring with that condition—the kind of wholesale and directed selective breeding of humans suggested by the word “eugenics” is immoral, and I don’t favor it at all.

On to more tweets. In this one, Curtis flaunts his expertise, but that doesn’t make the data showing him wrong any less convincing:

I have published hundreds of scientific papers on human genetics including on intellectual disability, mental illness and the predictive ability of genetic. You can view the list here:

On to his objections:

Animals are bred in controlled environments and have short generational times with large numbers of offspring. In these circumstances selective breeding can produce desired changes in a small number of specific traits such as milk yield or racing performance.

There are a number of different kinds of reason why eugenics would not work. One is that humans have long generational times and small numbers of offspring. This would make any selective breeding process extremely slow.

Well, “controlled environments” doesn’t mean that selection wouldn’t work, any more than saying selection wouldn’t work in nature because the environment in nature is variable. Artificial selection in animals is successful even in variable environments: I could, for example, select for more bristles on Drosophila flies, even while changing the type of food they get every generation and letting them experience variation in room temperature. We’d still get an increase in bristle number over time. If you think otherwise, I’d bet you a lot of money that you’re wrong.

The “long generation time” of humans isn’t a barrier to getting a result with artificial selection. It only means that, in terms of years (not generations), getting a response would be slower. But not infinitesimally slow!

For example, if you have a trait like height, which appears to show a heritability of about 0.8 (80%), then if you breed only from a group of humans whose average height is 5 inches above the population mean, in the next generation (ca. 20 years later), the response to selection—the average height of the selected group’s offspring when mature—would be 5 X 0.8, or four inches above the mean. That is, you would have raised the height of the population by four inches. That’s a big change in one generation: you’ve gone 80% of the way to your goal. It all depends on the heritability of the trait (which is usually appreciable) and how strongly one selects.

The “breeder’s equation” for this kind of calculation is simply response to selection = heritability of the trait in that population X the strength of selection practiced. And in fact this experiment is performed in miniature every day: tall couples produce tall offspring, short ones produce short offspring. That is really a form of artificial selection performed because couples tend to mate assortatively by height. Each couple mating gives us an idea of how much variation in that trait is genetic.

Finally, the low number of offspring doesn’t matter so long as you can keep the population going after selection. Note that offspring number doesn’t figure in the breeder’s equation.

As for the statement “selective breeding can produce desired changes in a small number of specific traits such as milk yield or racing performance”, that’s extremely misleading. As I’ve said before, I’m aware of only two artificial-selection experiments, out of hundreds practiced on genetically variable populations, that failed to yield a response, and both of those experiments were mine. (I was selecting on “directional asymmetry”, a trait with very low heritability.) “Small number of specific traits” is the misleading bit here. Better that he said, “selective breeding can produce desired changes in almost any trait.” After all, remember what Darwin said in The Origin, a conclusion based on breeders’ results before evolution and genetics were accepted or even understood:

 “Breeders habitually speak of an animal’s organization as something quite plastic, which they can model almost as they please.”

That, of course, means that animal traits have substantial heritability, for it is that heritability that make animals (and plants!) quite plastic. And so it is with humans, for we have evidence that natural selection has altered several human traits in the past 10,000 years or so, and in populations that are relatively small.

Another tweet by Curtis:

Another reason is that humans are exposed to very different environments, so most of trait variation is not due to genetic factors but to differences in environment. One consequence is that it makes it hard to identify subjects who have desirable genetic characteristics.

Here Curtis is again being misleading. What we do know from studies of heritability in our species is summarized in the article below (click on screenshot). The article shows that virtually all human traits have appreciable heritability (“selectability”), with none having zero heritability. And is it really hard to identify humans who are taller than others, or have higher IQs or better teeth? Yes, there is often substantial environmental variability contributing to the trait variation (diet and education in the cases I’ve cited), but this doesn’t mean that selection wouldn’t work.

Here’s the paper’s summary, showing that most traits have a substantial heritability (49% means that about half of the variation among individuals in a population is due to “additive” genetic factors). Further analysis suggests that (shared) environmental influences aren’t overwhelmingly important in these twin studies. Other studies of both identical and fraternal twins reared together and apart also show a substantial heritability and lower environmental effects than expected (see here, and here, for example). Further studies using not twins but identity by descent (e.g., here) also confirm heritabilities derived from the twin studies.

And from the paper’s discussion (my emphasis):

We have conducted a meta-analysis of virtually all twin studies published in the past 50 years, on a wide range of traits and reporting on more than 14 million twin pairs across 39 different countries. Our results provide compelling evidence that all human traits are heritable: not one trait had a weighted heritability estimate of zero.

That means that virtually all human traits would change when subject to artificial selection.

More of Curtis’s tweets with my responses.

We can now measure genetic potential directly from genetic markers and what we know from this is that these genetic predictors perform extremely badly. We can also tell that there are many important, very rare genetic variants which we will never be able to identify. 9/n]

Individual genetic markers are largely irrelevant here; what is important in judging whether selection would “work” is the heritability of the trait in the population, which reflects variation at all relevant genes, not just one or a few genetic markers. Again, using one or a few genetic markers is not the way to change traits. The way to change them is to select for or against certain trait values.

“We should bear in mind that harsh selection pressures have been acting on humans up to the present and that there may be very little scope for overall improvement. In any event, we can confidently say that selective breeding to improve desirable traits is not practicable.

Here Curtis is saying something not supported by the data. We know that there is still substantial genetic variation in humans from the heritability studies above, which directly contradict Curtis’s claim that “there is little scope for [change].” The average heritability at present is nearly 50% among all traits, which means that there is huge scope for “overall improvement” (I prefer “change”, as I don’t know what would constitute “improvement” in humans.) Of course it’s not “practical” to perform such broad-scale selection as a form of eugenics because of moral considerations, but that’s separate from whether that kind of selection would change the mean of a population.

With a recessive disease it may be possible to eliminate cases of the disease from the population using a combination of carrier testing, prenatal screening and selective termination. However this is not eugenics because the variants are still present in the population.

Of course that kind of selective breeding (termination of genetically afflicted embryos) is eugenics! Some variants would remain in the population, but their frequency would be reduced. That is a response to selection! And that involves “terminating” (a euphemism) genetically defective embryos. Just because calling selective elimination of embryos “not eugenics” doesn’t make it not eugenics.

Again, using one or a few genetic markers is not the way to change traits. The way to change them is to select for or against certain trait values.
TLDR: People who support eugenics initiatives are evil racists. Also, modern genetic research shows that eugenics would not work. 19/end

The first part of the statement is true in a qualified sense. However, “eugenics” practiced as “elimination of cases of disease from the population,” as Curtis mentions above, are certainly “eugenics initiatives”, and most of us support such practices. That doesn’t make us evil racists. What does make us evil racists is selective breeding practices on entire races or populations with an eye to differentiating races.

The second part of the statement—that artificial selection on human populations wouldn’t work—is just wrong, and dead wrong. I’m surprised that a man of Curtis’s expertise would make a statement like that. His Twitter thread should not be used as evidence against Dawkins’s claim for the efficacy of artificial selection in humans.

Klinghoffer’s second approach is to cite Behe’s claim that while artificial selection may create some success changing species, it can’t effect big changes. It can create breeds of dogs from wolves, for instance, but can’t change a wolf into a puma. This is an old creationist trope. Quotes from Klinghoffer and Behe are indented:
In an email, a geneticist friend notes the irony. Darwinian evolution is a massive extrapolation from selective breeding in animals. Of course animal breeding “works,” up to a point. Darwin in the Origin of Species cited the efforts of pigeon fanciers. In a New York Times book review, Dawkins once taunted Michael Behe with the successes of dog-breeding. But there are limits. Dogs can’t be bred to become cats, nor pigeons into bats. There appear to be set limits.

There appear to be set limits. Why? Behe has noted the problem that dog-breeding, canine eugenics, is accomplished largely by breaking genes:

Popularizers of evolution said if we can breed dogs that are so different from each other and only do it in the past few hundred years, how much better could nature do? But again, we didn’t know what was going on in the biology of these dogs. In the past 10 years, the entire genomes of many different dog breeds have been sequenced. And again, it turns out if you want a Chihuahua, you can break one of the genes involved in growth. If you want French poodles with curly hair, you break a gene involved in hair growth. If you want a dog with a short muzzle, you break a gene involved in facial shape development.

I and others have already refuted Behe’s claim (see also here and here) that selection for new features is ineffective because it involves broken genes that eventually stop selection in its tracks. And besides, the kind of changes that racist eugenicists proposed in the past (and again, I don’t favor them) are small-scale changes of the type involved in other forms of artificial selection. They didn’t propose turning humans into pumas!

Klinghoffer goes on:

Dave Curtis’s well informed observation is that even given the success of animal breeding, the analogy with humans is mistaken. But that leaves evolution…where? The extrapolation from dogs or pigeons to macroevolution fails because building genuine biological novelties, not just a Chihuahua as distinct from a poodle, requires more than merely breaking stuff, aka devolution, as Behe has shown in his book Darwin Devolves. If the many wonders of the animal world could not have proceeded from Darwinian blind shuffling alone, then human evolution, which can’t even stand on the shaky ground of human eugenics, all the more cannot have done so. 

As I’ve showed, Curtis has no data supporting him, and considerable data contradicting his claims. But in the end, this whole kerfuffle has nothing to do with macroevolution: it’s about microevolution. Even noting that, I’ll argue—but not here—that the IDers’ supposed “unbreakable barrier” between microevolution and macroevolution is totally bogus.

32 thoughts on “Discovery Institute makes hay of Dawkins tweet, and a geneticist mistakenly says that artificial selection won’t work in humans

  1. What is it about genes that is so scary that people conclude that the only position that is morally acceptable to hold is that genes are not having any effect?

    That seems to underpin many stances, including: (1) “eugenics does not work”; (2) “humans are born blank slates”; (3) “genetics cannot affect a kid’s schooling or exams scores, it’s all environment”; (4) “sex does not exist (it’s caused only by social stereotyping)”; (5) “there’s no difference between men and women’s brains, their group-average psychology and attitudes are identical”; (6) “race (= shared ancestry clustering) is not a biologically meaningful category, but is a purely social construction”. Et cetera.

    1. I think it is deeper than just genes. The ‘unseen’ world is difficult to comprehend and moral positions are where people cling on to when they are scared or don’t know the answers.

      GMO, EM radiation from cellphones, radiation fallout from Fukushima, vaccines…all difficult to conceive what the consequences and correlations might be.

    2. What is it about genes that is so scary that people conclude that the only position that is morally acceptable to hold is that genes are not having any effect?

      I suspect it is part of a larger aversion to naturalism generally. If naturalism is all there is then we are born, we live, and we die. There is no grand purpose or absolute morality to be found. We have to wing it. Bad things can happen to good people and good things can happen to bad people. Life is beating back the chaos until we can’t do it any more.

      But supernaturalism is the escape hatch from uncertainty and offers certainty. Some people prefer an uncomfortable certainty to no certainty.

      Now if the aversion to naturalism has a genetic component…

    3. Scientists are well aware of many types of bias (e.g. financial conflicts of interest, confirmation bias, etc.), but the most insidious types, in my opinion, are those related to equity. Scientists are overwhelming liberal, and we tend to be uncritical towards ideas that support our political views. While this has been around for decades (these topics were debated by the likes of Gould and Lewontin), they seemed to have really taken off now that the “woke” ideology has become widespread in academia.

      I’m very concerned about the future of academic discourse, as most scientists are afraid to speak out against this stuff. Without any pushback, opinions can become established as dogma. These ideas can then have a real impact on important decisions. For example, I’ve seen people question the need to recruit diverse ethnic groups in drug trials because they were taught that there are no meaningful differences between different human groups outside of those related to sun exposure. Transgender participation in sports is another important issue. If male to female transgender people retain some of their male characteristics post-transition, there are serious safety concerns in contact/combat sports. The data seem to point to this being true, but there has been a lot of pushback towards this.

      I absolutely appreciate scientists like Dr. Coyne who have the courage to speak up on this topic, but I’m afraid that it’s mainly the scientists nearing the end of their careers who are able to speak out. I’m at the start of mine, and I admit that I have stopped speaking out due to fears about it impacting my career.

  2. If “artificial” selection does not work then natural selection does not work either because there is no difference between them. Then how did humans and other species appear? In effect, Curtis is denying the process of evolution.

    1. “Another reason is that humans are exposed to very different environments, so most of trait variation is not due to genetic factors but to differences in environment.”

      I am trying to see what Curtis means by this statement. On one hand, the point of artificial selection is to provide an environment where those with the desired traits thrive over generations.

      Or perhaps he means to say that individual traits present differently due to the environment in which a person is born or lives. But that is obviously false. No matter how long I lived in Japan, I was never going to develop epicanthic folds. My parents lack them, so I do as well.

      But reading Cutis’s posts online, he seems to follow all the standard progressive causes. One thing I have observed is that when such a person finds a conflict between their politics and in this case science, their progressive politics win every time.

  3. Curtis’s main point seems to be that eugenics wouldn’t work because he defines anything that works as not counting as eugenics.

    My understanding is that reducing disease, exactly the thing he says will work, was one of the main things eugenicists wanted to achieve.

  4. Hey, he is putting my name is a bad light ;(

    There is a difference between government forced eugenic and parents choosing traits in their offspring. If I had been given the choice, I certainly would have chosen children with less chance of the diseases that run in my family (heart disease, depression.) Less important traits such as IQ, height and vision would have been lower priority but I am glad that I have smart kids and I wish my son did not need glasses.

    This type of choosing is available to some degree now and will grow in the future. My kids are in their teens and I imagine at least one of my grandchildren will be chosen for some traits. It’s inevitable and I am OK with it.

  5. The “eu” in genetics refers to “good” (like euphoria), the “dys” in dysgenics refers to “bad” (like dysfunctional).

    These are normative concepts, although most people would regard a genetic predisposition toward violent crime as “bad” genetics.

    The point of this remark is that all societies have laws and customs that channel reproduction in various ways, whether you are talking about dating apps or arranged marriages. These different regulatory regimes result in different outcomes, both in the share of genes represented in subsequent generations, as well as factors like maternal health and social environment (if the fertility of the low SES segment exceeds the fertility of the high SES segment, you will have higher rates child poverty, abuse and neglect, etc). You can look at the bottlenecks on Y chromosome correlating to the Bronze Age:

    Every society provides a regulatory regime for human reproduction, and thus, every society is practicing a form of eugenics or dysgenics (although the characterization of the regime as “eugenic” or “dysgenic” depends upon the normative frame). The only question is whether it is done consciously or unconsciously. Obviously, it is important that eugenics “doesn’t work” because that way you don’t have to think about it.

    1. Here is an article on the Catholic Church’s extreme efforts to root out cousin marriage and how it supposedly gave rise to WEIRD countries (Western Educated Industrialized Rich Democratic) and a more individualistic and universalist ethos:

      Now is this true? That can probably be debated.

      Assuming it is true, then essentially you have a eugenic selection process against clanishness and nepotism, and it is unclear whether it was intentional or unintentional. Further, get rid of broad incest taboos, and you can presumably revert societies back.

    2. I agree. Many of our social policies have eugenic or dysgenic effects, and a wise society would consider those effects when crafting and evaluating policies. All else being equal, a eugenic policy is better than a dysgenic one, and to ignore this axis is irresponsible leadership.

      But as Coel alluded above, it seems people in the West have in recent decades become shy about the realities of genetics as they apply to humans, including people who should know better like Dave Curtis.

      1. I’m not sure its so simple. Is clannishness and nepotism bad?

        If I fall in love with a first cousin, should I be able to wed and produce offspring? Can society say no because of societal consequences that will take place centuries down the course of history? It was a lot easier when it was just down to pray, pay, and obey.

        1. I’ll note that my message was written before your later comment about clannishness, nepotism, and incest appeared, so it wasn’t in response to that, and I might have misunderstood the final sentence of your original comment, which was somewhat vague. My overall point was that given how our genomes are closely tied to our well-being, wanting to improve the society’s gene pool should be as unobjectionable as wanting the public to exercise more, smoke less, and undertake other health initiatives. The knee-jerk reaction to the word “eugenics” is like equating “exercise” with the imprisonment of fat people in aerobics camps… and the topic’s avoidance by our leaders is as irresponsible as avoiding discussion and policies to improve other aspects of public health.

          Now, I’ll respond to your questions, just in case you were actually interested. 🙂 Clannishness and nepotism are probably good in some situations. We love our families more than strangers, and do things for them that we wouldn’t do for others. Perhaps it wouldn’t be that way in a utopian world, but in the real world pure selflessness is easily exploited. In any case, that kind of clannishness is our nature and policies shouldn’t try to oppose human nature any more than necessary. (I think the basic job of government is to align self interest with the public interest, and that’s more easily done when you go with the grain of human nature rather than against it.) There are surely situations where clannishness and nepotism harm society, like government officials appointing their family and friends rather than the most qualified candidates. And it may be in the public interest to convince people to spread their affinities (and wealth and effort) wider than they naturally would, but not too widely (e.g. not to the whole world).

          As for incest, I could imagine a policy that says “Be with whomever you like. We’ll offer free genetic screening, but if you refuse the screening or ignore the results and perform a known hisk-risk mating, then you’ll get no tax credits for any children you produce, and will face a tax penalty if you produce a child with an easily preventable genetic disease, to help offset the additional cost to society.” As science advances, we have the opportunity to sharpen some of the blunt instruments from the past.

          As for the idea that opposition to incest is the cause of our WEIRDness, it’s interesting but seems rather preliminary, and even if true it’s not clear that the prohibition on incest is still functional and required. (We might stay WEIRD for other reasons.)

          I think it’s important for society to establish a “regulatory regime for human reproduction”, and it’d be better to base it on clear and open thinking about what we want and how best to achieve it rather than emotional reactions, random luck, and/or dogma. Take the birth rate for example. Should we just leave it to chance? Singapore’s is down to 0.83 children per woman, for example. Not a single European nation is at replacement levels and many are closer to 1.0 than 2.0. All WEIRD nations are shrinking, or growing only due to immigration, and it’s far from clear that mass immigration from non-WEIRD nations will preserve WEIRDness. Perhaps we should actually get together as a society and establish a regulatory regime to at least sustain our existence… but I guess that kind of conversation just can’t be had these days.

  6. Speakers & writers should be required to define their terms. Sorry, Dr. Dawkins, this means you, too, even in the short span allowed on the Twits.
    On this site, we are at least aware of the difference between the scientific definition of “theory” and common usage. Looks like the same difference should be highlighted for “eugenics”.

    1. But Dawkins’s sentence in that Tweet that eugenics “works for cows, pigs, dogs and roses” pretty clearly defines what he meant by both “works” and “eugenics”.

  7. External to the Creationist/ID crowd, the other kerfuffle-ers are of course the woke crowd. And it seems obvious that their angst is in large part because Dawkins said it. They are reading a tweet while under the influence of “Dawkins derangement syndrome”.

    1. Although Richard Dawkins recorded attitude to most issues is liberal rather than reactionary, the “woke” have never forgiven him for “Dear Muslima”.

  8. I’m glad to see this dissection of Curtis’s tweet thread from someone who knows genetics and biology. I saw the thread, but didn’t have the knowledge to judge some of his arguments.

    It’s amazing that he gets so hung up on the generational time as a reason it could not work. Imagine alien visitors to Earth with 1000yr lifespans and a reproductive age of 130 years. To such a species, our generational time would be as trivial as dogs are to us. Can anyone doubt that should they want to breed humans to be stronger, say, that they could do so?

  9. Thanks for this post. Probably won’t be seen by many but good to see a blip of rationality amongst a sea of twitter posts. I still have to wonder why Dawkins bothered tweeting that (or a lot of what he tweets) if he’s not intentionally trying to get on people’s nerves. My best guess is because that day was the anniversary of Francis Galton’s birth, probably info unknown or neglected by most.

      1. Your efforts are greatly appreciated. This piece gives me hope that the truth shall out. I hope Dawkins, at least, sees that he is being well defended.

  10. “I don’t know what would constitute ‘improvement’ in humans.”

    We could start by eliminating wokeability from the science community. 😎

  11. The Discotute was founded, what, a quarter century ago? Here’s hoping three generations of imbeciles is enough.

  12. The anti-science and ‘woke’ atheists have a lot in common with the faith-heads and flat-earthers, these days.

    A lot of PZ’s ‘horde’ are essentially at the “there are other ways of knowing” stage.

  13. I have heard (not sure where) that one trait which is resistant to selective breeding is offspring sex ratio. If you are breeding cattle, for instance, I think it would be good to increase the ratio of female offspring.

    Is it true that this is hard to do?

  14. Unsurprisingly, The Friendly Atheist selectively edits Dawkins’ statement to smear him as a Nazi. They really hate Dawkins over there.

  15. Is this eugenics?
    UK stats.
    92% of mothers who have a foetus diagnosed with Down’s Syndrome opt for a termination.

  16. Of course it works for humans some examples (well, a bit t.i.c.)
    – The high incidence of myopia in Jews and Chinese, both have a long tradition of literacy, spanni g hundreds of generations.
    – The high incidence of deep set eyes among some Khoi tribes, their weapon of choice for millennia was the “knopkirie”.
    – The rise of the ‘snowflakes’ keen on a safe environment in industrialised societies, the others were disproportionally selected by cars overrunning then before reproductive age.
    – And I didn’t mention lactose tolerance, did I?

  17. In one of the ‘Science of Discworld’ books (I think) the secular Jewish writer Jack Cohen suggested that the custom in Eastern European ghettos of boys’ marriagability being based on their performance in grueling bar-mitzvahs may lie behind their descendants’ abilities as lawyers.
    Equally, a Jamaican colleague recalls being told at school that Jamaicans’ sporting prowess is partially due to their aggression, and that this was due to slave ships selling particularly aggressive captives at the first island they docked at, which was apparently Jamaica.
    Assuming these two stories are reliable, they both imply that selective pressure on groups of humans can affect heritable characteristics. I sometimes wonder if the above-European average height of the Dutch has anything to do with being neutral in WWI; I imagine that being relatively tall was a disadvantage in the trenches.

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