Jerry Fodor: Still getting it wrong about evolution

Way back in 2007, when I was still a neophyte science blogger, Rutgers University philosophy professor Jerry Fodor published an op-ed in the London Review of Books called "Why Pigs Don't Have Wings." It was a critique of a straw man version of evolutionary theory characterized by a brand of adaptationism so narrow that (if it were at all true) biologists could be charged with just making things up as they went along. But Fodor was not so much concerned with science as the extension of evolutionary ideas outside of biology. Motivated by his irritation with evolutionary psychology, a subdiscipline he believed was "Darwinism" at its worst, Fodor crowed that natural selection should be exiled from evolutionary theory altogether.

Like many other science bloggers I criticized Fodor's confused interpretation of evolutionary theory, but apparently he just waved away any opposing arguments from us lesser creatures. The philosopher is now making the rounds to promote the new book he wrote with Massimo Piattelli-Palmarini, called What Darwin Got Wrong, and in an interview published in Salon Fodor had this to say of the responses he has received from bloggers:

Most of the backlash to the book so far has been on blogs, which have been pretty obscene and debased. What's upsetting is that they tell you that they think you're an idiot, but they don't tell you why -- people who aren't part of the field or who may not, in many cases, know much about Darwin. I'm not sure that all people who have been blogging about it are very sophisticated. It's frustrating because you don't know who you're talking to.
At some point you just have to stop worrying about the reaction and worry if the argument is any good. I don't take the arguments that say, "This that can't be true because of what I learned in Biology 101" very seriously.

As might be expected of someone who does not take criticism well Fodor casts all bloggers are ignorant hacks who can do nothing other than offer "obscene and debased" rants about his work. Unfortunately for Fodor this characterization does not hold up. Back in 2007 Jason Rosenhouse wrote a thoughtful, detailed response to Fodor's London Review of Books piece, and Bob O'Hara has written an excellent takedown of the recent editorials Fodor and Piattelli-Palmarini have been churning out, neither of which I would call "obscene" or "debased." And Fodor also ignores that he has received a fair bit of praise from the intelligent design crowd, both from the cesspool of nonsense that is Uncommon Descent to the Discovery Institute mouthpiece Evolution News and Views (though, in true creationist fashion, these supporters of What Darwin Got Wrong care more that it can be construed as a case of "friendly fire" than what the book actually says). Thus far intelligent design advocates seem to be among Fodor's biggest fans.

If anything, the "people who aren't part of the field or who may not, in many cases, know much about Darwin" seem to be Fodor and Piattelli-Palmarini as shown by their refusal to engage criticisms of their work in any meaningful way. Much like a creationist, Fodor seems to be taking the criticisms made of his work as a sign that he is winning the battle against the menacing giants of strict "Darwinism" that so threaten him. In reality he is only tilting at windmills.

Fodor's entire argument hinges upon a broad caricature of evolutionary theory which only seems to exist in his imagination. In the Salon interview he states:

The main thing Darwin had in mind with natural selection was to come up with a theory that answers the question, "Why are certain traits there?" Why do people have hair on their heads? Why do both eyes have the same color? Why does dark hair go with dark eyes? You can make up a story that explains why it was good to have those properties in the original environment of selection. Do we have any reason to think that story is true? No.
According to Darwin, traits of creatures are selected for their contribution to fitness [likelihood to survive]. But how do you distinguish a trait that is selected for from one that comes along with it? There are a lot of interesting structures in creatures that have nothing to do with fitness.
Some variants in selection are clearly environmental. If you can't store water you'll do worse in a dry environment than if you can. But suppose that having a high ability to carry a lot of water is correlated for genetic reasons with skin color. How do you decide which trait is selected for by environmental factors and which one is just attached to it? There isn't anything in the Darwinist picture that allows you to answer that question.

Fodor's response belies the fact that he is responding to a form of evolutionary theory that does not actually exist. Charles Darwin did not propose natural selection to explain the existence of individual traits but to provide a comprehensible mechanism by which organisms can change over the course of generations. The way traits affected survival and reproduction were a part of his idea, but even Darwin himself was not as strict a "Darwinist" as Fodor proposes. I would not be surprised if Fodor eschewed doing any historical research at all for his work. As said by Peter Forbes in his review of What Darwin Got Wrong:

Fodor is a philosophical fl√¢neur: he loves cheap jokes and affects a kind of provocative insouciance. His 2003 book on Hume states at the outset that he "could even write a book on Hume without actually knowing anything about him," and then claims to have done so.

Fodor's lack of historical scholarship allows him to paint modern scientists with the same brush without so much as a second thought. According to Fodor the business of evolutionary biologists is to sit about identifying traits and coming up with "Just So" stories to explain them. On the surface this might seem similar to Stephen J. Gould and Richard Lewontin's critique of the "adaptationist" regime in their famous paper "The Spandrels of San Marco and the Panglossian Paradigm", but whereas Gould and Lewontin looked to extend evolutionary theory beyond considerations of selection and adaptation alone Fodor would like to throw the whole thing out in preference of nebulous "self-organizing" principles. As far as I can tell Fodor prefers a "bottom up" type view of evolution in which organisms change according to internal principles and constraints, and it is only afterwards that they spread into a different type of habitat or niche. It is a sort of "Great Chain of Being" type thinking in which every form that is possible will eventually evolve, and if a creature does not exist there must be some sort of internal constraint that prevented its appearance.

If I have understood correctly (which, I must admit, Fodor makes it unnecessarily difficult to do) this explains why he has grossly misinterpreted the way evolution by means of natural selection works. Let's run with his desert scenario. It is not as if the ability to store water is the result of some kind of macromutation which organisms either do or do not have. As Darwin aptly showed with the analogy to artificial selection variations provide the raw stuff for natural selection to work. Members of a population may differ in their abilities to retain moisture, and if those with more ability to do so start to create a new niche or exploit the resources in the dry habitat which is otherwise inaccessible to others then they may have increased reproductive success (and under the right conditions speciate into a new type better adapted to a dry environment).

Admittedly this is hypothetical, but Fodor does not seem very interested in diving into real examples. By refraining from engaging scientists over actual research he is free to ask absurd questions that only impress those who know as little about evolutionary theory as he does. Take, for example, his exposition on why there are no flying pigs in his abstract published in the London Review of Books:

For example, nobody, not even the most ravening of adaptationists, would seek to explain the absence of winged pigs by claiming that, though there used to be some, the wings proved to be a liability so nature selected against them. Nobody expects to find fossils of a species of winged pig that has now gone extinct. Rather, pigs lack wings because there's no place on pigs to put them. To add wings to a pig, you'd also have to tinker with lots of other things. In fact, you'd have to rebuild the pig whole hog: less weight, appropriate musculature, an appropriate metabolism, an apparatus for navigating in three dimensions, a streamlined silhouette and god only knows what else; not to mention feathers. The moral is that if you want them to have wings, you will have to redesign pigs radically. But natural selection, since it is incremental and cumulative, can't do that sort of thing. Evolution by natural selection is inherently a conservative process, and once you're well along the evolutionary route to being a pig, your further options are considerably constrained; you can't, for example, go back and retrofit feathers.

Here Fodor makes a few points that are already well-known and draws entirely the wrong conclusion. There are places to put wings on a pig (the arms, as bats, birds, and pterosaurs so beautifully illustrate) but in order to have a "pig with wings" you would have to modify the animal to such an extent that it would cease looking like a pig altogether. Changes to its posture, balance, weight, bone structure, body covering, etc. would need to be made in order to create a flying pig, but the idea that (in the fullness of time) natural selection absolutely could not radically alter organisms does not follow. We know from the fossil record, for example, that fleshy-finned fish were adapted into the first terrestrial vertebrates and that one group of descendants of those early tetrapods much later became adapted to life in the sea to become whales. (Hell, I have just written a whole book about just these kinds of transitions.) Yes, the ways organisms vary and can be adapted are constrained by a variety of factors, from development to functional mechanics, but it does not follow that those constraints are so powerful that they negate any creative power behind natural selection.

None of these ideas are new or revolutionary. Stephen Jay Gould, among others, often talked about constraints and contingency in his work, but when he did so it was an extension of what he felt was an evolutionary synthesis too narrowly focused on changing gene frequencies and little else. Whether Gould was correct in this assessment or not is open for debate, but from what I can tell at least some evolutionary biologists are taking a more interdisciplinary approach in which fossils, genes, and development are all brought together to understand what G.G. Simpson famously called the "tempo and mode" of evolution. Modern evolutionary science does not resemble the caricature Fodor presents at all, and the philosophers ramblings are especially annoying since it seems that most of his major points have been cribbed from Gould but turned on their heads.

But, in truth, I could have (and maybe should have) cut this response to Fodor's nonsense short. His objections to "Darwinism" are not based in sound science but his distaste by the way evolutionary ideas (rightly or wrongly) have encroached into realms outside biology. It is not Fodor's aim to rescue evolutionary biology with a new synthesis. The objective is the opposite; to deny evolutionary biologists any ability to form coherent theories so that we can leave Fodor in peace. By every indication What Darwin Got Wrong is not so much a bold challenge to evolutionary orthodoxy as a protracted, barely comprehensible whine, and it will probably fall from visibility as soon as Fodor stops flogging it to publications too enamored with his stance as an iconoclast to actually think about what he is saying.