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  • Science vs. Ideology in Genetics, in which Richard Dawkins and Professor Ceiling Cat Admonish David Dobbs

    Posted on December 8th, 2013 Helian 1 comment

    Cultural determinism is like the Paris fashions.  It defies ridicule.  The idea is so useful that it won’t drown, despite the torrent of contradictory facts it has been submerged under lately.  The cobbling of utopias is great fun, and utopia is ever so much more plausible if only everything can be changed to the heart’s desire by culture and environment.  One of the more flamboyant examples of the phenomenon recently turned up in Aeon Magazine in the form of an article penned by science journalist David Dobbs.

    The title of the article, Die, Selfish Gene, Die, is provocative enough.  The Selfish Gene, of course, was the subject of a book with that title by Richard Dawkins.  Rubbing salt in the wound, Dobbs adds the byline, “The selfish gene is one of the most successful science metaphors ever invented. Unfortunately, it’s wrong.”  All this irritated Dawkins’ friend Jerry Coyne, to the point that he not only read the rather lengthy article, but penned a pair of rebuttals on his Why Evolution is True website.  It wasn’t hard.

    Dobbs’ claim that Dawkins’ selfish gene version of evolution is wrong was based on his embrace of the idea of genetic accommodation.  Coyne (known to his students as Professor Ceiling Cat, for reasons that will be obvious to anyone who visits his blog) described the idea in his second rebuttal as follows;

    Today’s discussion is on what Dobbs and some of the heroes of his piece (especially Dr. Mary Jane West-Eberhard) see as the truly novel and non-Darwinian refutation of the selfish gene idea: the idea of genetic accommodation.  “Genetic accommodation” has other names: it’s also been called “The Baldwin Effect” and “genetic assimilation.”  But all of these names refer to a single mechanism: instead of existing genetic variation being subject to natural selection in an existing or changing environment, the environment itself evokes phenotypic (not genetic) variation, which is then somehow fixed in the species’ genome.

    Dobbs’ version of this idea leads him to some rather startling assertions.  For example, he writes,

    Gene expression is what makes a gene meaningful, and it’s vital for distinguishing one species from another.  We humans, for instance, share more than half our genomes with flatworms; about 60 per cent with fruit flies and chickens; 80 per cent with cows; and 99 per cent with chimps.  Those genetic distinctions aren’t enough to create all our differences from those animals – what biologists call our phenotype, which is essentially the recognizable thing a genotype builds.  This means that we are human, rather than wormlike, flylike, chickenlike, feline, bovine, or excessively simian, less because we carry different genes from those other species than because our cells read differently our remarkably similar genomes as we develop from zygote to adult.  The writing varies – but hardly as much as the reading.

    Great shades of Trofim Lysenko!  One can almost see the great Soviet con man in one of his Siberian laboratories, turning out a race of centaurs by astutely tweaking the “reading” of the genes of a zebra.  Where is Dobbs going with this?  Let’s cut to the chase and have a look at his thumbnail sketch of genetic accommodation:

    There lies the quick beating heart of her (Mary Jane West-Eberhard’s) argument: the gene follows. And one of the ways the gene follows is through this process called genetic accommodation. Genetic accommodation is a clunky term for a graceful process. It takes a moment to explain. But bear with me a moment, and you’ll understand how you, dear reader, could evolve into a fast and deadly predator.

    Genetic accommodation involves a three-step process.

    First, an organism (or a bunch of organisms, a population) changes its functional form — its phenotype — by making broad changes in gene expression. Second, a gene emerges that happens to help lock in that change in phenotype. Third, the gene spreads through the population.

    For example, suppose you’re a predator. You live with others of your ilk in dense forest. Your kind hunts by stealth: you hide among trees, then jump out and snag your meat. You needn’t be fast, just quick and sneaky.

    You get faster. You mate with another fast hunter, and your kids, hunting with you from early on, soon run faster than you ever did.

    Then a big event — maybe a forest fire, or a plague that kills all your normal prey — forces you into a new environment. This new place is more open, which nixes your jump-and-grab tactic, but it contains plump, juicy animals, the slowest of which you can outrun if you sprint hard. You start running down these critters. As you do, certain genes ramp up expression to build more muscle and fire the muscles more quickly. You get faster. You’re becoming a different animal. You mate with another fast hunter, and your kids, hunting with you from early on, soon run faster than you ever did. Via gene expression, they develop leaner torsos and more muscular, powerful legs. By the time your grandchildren show up, they seem almost like different animals: stronger legs, leaner torsos, and they run way faster than you ever did. And all this has happened without taking on any new genes.

    Then a mutation occurs in one grandkid. This mutation happens to create stronger, faster muscle fibres. This grandchild of yours can naturally and easily run faster than her fastest siblings and cousins. She flies. Her children inherit the gene, and because their speed wows their mating prospects, they mate early and often, and bear lots of kids. Through the generations, this sprinter’s gene thus spreads through the population.

    Now the thing is complete. Your descendants have a new gene that helps secure the adaptive trait you originally developed through gene expression alone. But the new gene didn’t create the new trait. It just made it easier to keep a trait that a change in the environment made valuable. The gene didn’t drive the train; it merely hopped aboard.

    In fact, all this is so banal, and so lacking in any serious departure from anything Dawkins said in The Selfish Gene, that Coyne apparently assumed that he’d missed something, and accused Dobbs of Lamarckism.  After all, if he wasn’t at least implying Lamarckism between the lines, there isn’t the shadow of a hook in this scenario on which to hang the claim that such “genetic accommodation” is in any way revolutionary, non-Darwinian, or non-Dawkinsian.  In fact, if you read the passage closely, you’ll see there’s nothing Lamarckian about it at all.  The kids and grandkids don’t get faster and stronger by inheritance or acquired characteristics, but merely by hanging out with their parental role models.  Evidently Dawkins himself noticed, because at this point he chimed in and wrote his own rebuttal, patiently Fisking Dobbs article, and quite reasonably pointing out that there was nothing in all this that contradicted Darwin or himself in any substantial way at all.

    Coyne and Dawkins concluded from all this that Dobbs was merely grandstanding.  As Dawkins put it, his article was,

    …infected by an all-too-common journalistic tendency, the adversarial urge to (presumably) boost circulation and harvest clicks by pretending to be controversial. You have a topic X, which you laudably want to pass on to your readers. But it’s not enough that X is interesting in its own right; you have to adversarialise it: yell that X is revolutionary, new, paradigm-shifting, dramatically overthrowing some Y.

    True enough, but as scientists often do, Dawkins sees the basic absurdity of the article clearly enough, but fails to see that it is absurd, not because it is bad science, but because it is an ideological morality tale.  Let’s allow Dobbs to explain the moral of the story in his own words:

    The gene does not lead, it follows.

    And ‘evolution is not about single genes’ (West-Eberhard) says.  It’s about genes working together.

    It’s not a selfish gene or a solitary genome.  It’s a social genome.

    Not the selfish gene, but the social genome.

    And so, thanks to the environment, the collective once again triumphs over the “selfish” individual.  If you don’t get the ideological point, dear reader, I’m not going to spell it out for you.  I’ll let the ideologues do that for themselves.  See, for example, Drugged Individualism, in the November 1934 issue of the American Mercury, or The Myth of Individuality (by Theodore Dreiser, no less) in the March issue of the same year.  The hive mind hasn’t changed much in 80 years.

     


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