I’ve just started reading The Origin Of Species, and if that strikes you as the sort of book that an ex-Victorianist should have read when she actually was a Victorianist then hush up now, please. One of the depressing things about the assaults on evolutionary theory has been the willingness of supposedly-sensible sections of the press to indulge the moronisms of intelligent design for the sake of a snappy editorial angle. The New Scientist cover above caused a lot of people grief, but before that, the London Review Of Books was quite happy to run an article by Jerry Fodor whose bio describes him as “working on a book about what Darwin got wrong” and whose body copy gives little to no impression of him having actually read The Origin Of Species even as far as I have (page 14, as of last night).
Fodor thinks he’s spotted two clinching failures in Darwin’s theory of evolution, one “more or less conceptual”, the other “more or less empirical”. Here’s his science-shattering conceptual argument:
There is, arguably, an equivocation at the heart of selection theory; and slippage along the consequent faultline threatens to bring down the whole structure. Here’s the problem: you can read adaptationism as saying that environments select creatures for their fitness; or you can read it as saying that environments select traits for their fitness. It looks like the theory must be read both ways if it’s to do the work that it’s intended to: on the one hand, forces of selection must act on individual creatures since it is individual creatures that live, struggle, reproduce and die. On the other hand, forces of selection must act on traits since it is phenotypes – bundles of heritable traits – whose evolution selection theory purports to explain. It isn’t obvious, however, that the theory of selection can sustain both readings at once. Perhaps the consensus view among Darwinists is that phenotypes evolve because fit individuals are selected for the traits that make them fit. This way of putting it avoids the ambiguity, but whether it’s viable depends on whether adaptationism is able to provide the required notion of ‘selection for’; and it seems, on reflection, that maybe it can’t.
I’ve read this article over several times with the feeling that I must be missing something, because the LRB couldn’t really have published something as stupid as this sounds, could they? I mean, when he asks, “were polar bears selected for being white or for matching their environment?” it isn’t just me who considers that to be a meaningless tautology, is it? I can’t think of any sensible reason to make a distinction between the selection of creatures and the selection of traits. I can’t even imagine what that distinction could mean: the traits are part of the creature. If mutation throws up a new trait that’s advantageous (or the environment changes to make a previously neutral trait into an advantage) then the creatures with that trait breed more and pass on that trait. If mutation throws up a new trait that’s disadvantageous (or the environment changes to make a previously neutral trait into a disadvantage), then the creatures with that trait will probably die without passing that trait on to many offspring. And if a trait is neutral, then it might flourish or fail by association with other traits. There’s no difference, as far as I can grasp it, between natural selection of a trait and natural selection of a living thing – unless Fodor imagines that traits are roaming around autonomously somewhere.
The basic argument of Fodor’s article is (I think) that evolution can’t explain everything. Living things aren’t perfectly tooled for their environment, and the vulgar adaptationism that claims a purpose to every trait is in error. Maybe Fodor’s confused the science coverage in the national press with real science; otherwise, why would he bother writing several thousand words about something that’s so obviously accepted among biologists? Something, in fact, that comes up 11 pages into The Origin Of Species:
There are many laws regulating variation, some few of which can be dimly seen. […] Some instances of correlation [of seemingly unrelated traits] are quite whimsical: thus cats with blue eyes are invariably deaf; colour and constitutional peculiarities go together, many of which remarkable instances could be given amongst animals and plants. […] Hence, if man goes on selecting, and thus augmenting, any peculiarity, he will almost certainly unconsciously modify other parts of the structure, owing to the mysterious laws of the correlation of growth.
Darwin, Origin Of Species (Wordsworth, 1998), pp 11-2
That’s Darwin saying that not every trait is selected for, that some thrive because they’re related to other traits that are selected. When Fodor says, “An adaptationist might well wonder what it is about dogs, cats etc that makes curly tails good for their fitness in an ecology of domestication. The answer, apparently, is ‘nothing’. Curly tails aren’t fitness enhancing, they just happen to be linked to tameness, so selection for the second willy-nilly selects the first”, he isn’t making a clinching argument against Darwin, he’s reiterating something that was said at the foundation of evolutionary theory.
When Fodor claims that “it’s not out of the question that a scientific revolution – no less than a major revision of evolutionary theory – is in the offing”, it just sounds like it’s Fodor who’s finally bothering to catch up with everything since Darwin, and he doesn’t seem to have understood what Darwin said particularly well anyway. Maybe his book will give a better account of this incredible development, but as this article stands, it’s extraordinarily disappointing that the LRB would publish something so obscure and anti-science.