Monday 7 November 2011

What Darwin Got Wrong: What Fodor and Piattelli-Palmarini Got Wrong

I've recently finished reading What Darwin Got Wrong, by Jerry Fodor and Massimo Piattelli-Palmarini. I was pre-disposed to its central thesis because I've always thought the Theory of Evolution, especially in its (very) Vulgar forms, such as Evolutionary Psychology, is just a tad on the weak side. By being for instance totally ad-hoc in all its meanings (see any paper by Imre Lakatos for explanations of the various forms of ad-hoc-ness.)

So let's understand one thing: God did not design the cockroach, though He may have had a hand in creating Eva Mendes. If Intelligent Design is the Conspiracy theory ("it's all God's doing"), then Evolution is the Cock-Up theory. Looked at as heuristics, Creation suggests we need to understand why purpose God put the hippopotamus on the planet, whereas Evolution suggests that we need to understand how a particular feature of the hippopotamus helps it flourish in its habitat, and how other hippo-like animals without that feature might have thereby been at a disadvantage. This is the "Africans have dark skin to protect them from the sun, while Swedes have white skin because they need what little sunlight they get to make Vitamin D really quickly" line of thinking. Darwin may or may not have been a gradualist: who believe the genome is subject to random variations which, if they give rise to advantageous features, will cause that version of the species to be preferred by females (or to be better at forcing itself on females, but Evolutionists tend to  be very PC, so they don't mention that bit) and so breed more than others.

That's the Vulgar view of Evolution. The obvious question is: who or what is doing the selecting? And how? What can't be happening is that species breed for fitness - otherwise no-one would marry anyone who didn't look (and behave) like Eva Mendes. People, let alone elephants, aren't smart enough selectively to breed their own species: and only a small number of humans have ever successfully bred other species. So what might be happening is not that this or that species thrives but that the others starve: evolution proceeds by elimination. This is the usual story about what happened to the dinosaurs: they couldn't take the global freezing after the meteor. On this account, evolution isn't about the most fit, but the least vulnerable, or most adaptable. That would explain cockroaches and Rupert Murdoch. But it's nowhere near as nice a story, not very flattering for alpha male academics and justifies the wrong sort of free-market capitalism. Not that any of that has to do with the attraction of a scientific theory to the layman.

Vulgar Evolution is what's not known in the trade (but should be) as a Monet theory: looks good at a distance, but a real mess close up. Ask it a sensible question, like why there are still so many ugly and dumb people in the world, if smarts and looks are advantageous, and they are likely to come back with an answer like "fitness is about reproducing, not being successful or cool, and smart cool people reproduce less because they have other things to do at night." Which suggests that evolutionary fit people can be unemployable nail-biters with bad skin, and only survive because the evolutionary less fit don't let them starve. In other words, smart people are dumb people's way of staying alive. The pop literature is full of stuff like this, and it's entertaining in the way that an episode of CSI Vegas is: but just as no-one confuses CSI Vegas with real forensic work, they aren't likely to confuse pop evolutionary theory with real science either. (Except a lot of people do, and that's a problem.)

Fodor and Piattelli-Palmarini choose to take the philosophical high-road. There's rather forbidding talk of "nomological laws", "natural kinds", agency, intentionality, counterfactuals and the distinction between generalisations and actual Laws of Nature. For one thing, they tell us, laws of Nature "support counterfactuals", but I had to guess what that means, because they didn't explain it. These ideas are very, very far from being "common ground" (another signature phrase) amongst philosophers, and to base a critique of a thriving Pop Science industry on them is, well, like saying Natalie Portman isn't a "real" ballerina because she didn't hold her arms as well as the girls in the corps. Who cares about details like that? She did a lot of her own moves, and besides, they needed a talented actress who could dance competently, not a talented dancer who could act competently. I'm not going to discuss the ideas of natural kinds and nomological laws because, well, I thought those ideas were extinct (so Carl G Hempel, so 1945).

As a good Lakatosian, I can ask: who cares if the detailed logical structure of Evolution is a little shaky? Does it have heuristic power? Have people working with it suggested and neatly solved a whole bunch of interesting problems? To which the answer is: Yes, and No. Has it solved at whole bunch of scientific problems? No. Of course not. The serious work in understanding why animals and plants are how they are comes from genetics - and here is something very important to understand: you can be a creationist and support genetic research. After all, if God created the universe, She created the genome as well. Understanding how the genome works, how it interacts with its environment, is part of the worthy task of understanding and celebrating the work of God. The study of DNA comes from the Mendelian programme, not from Darwin: DNA was the answer to "what's a gene?". Post-DNA evolutionary theories have had to bolt genetics on: it doesn't fit in naturally.

Has it solved a whole bunch of political and employment problems for intellectuals? By Darwin and Freud, yes. Writing an Evo pot-boiler is a terrific way for a cute-looking alpha academic male to make a quick buck: even writing a not-so-best-seller can get you into some hip soirees. While Evolution is not the "universal acid" for genuine theories, it is the litmus test for dangerous religious cranks: they can hide, but unfailingly they turn purple when you suggest that great-grand-daddy was an ape.

What's wrong with Evolution is not that it is, as Fodor and Piattelli-Palmarini point out, a species of history, and therefore a tale of One Damn Thing After Another. It is that Evolution makes no novel predictions and it does not generate technology (to repeat: all the technology comes from genetics, and genetics is not intrinsically evolutionary). What it does, and why it is so popular, is to provide an interpretation of the world. People love an interpretation: it tells a story, or it can be used to tell a story, about all sorts of human behaviour, no matter what that behaviour is. Why do girls sleep around? To get the best alpha sperm for their babies. Why do girls not sleep around? To keep the provider father faithful and happy. Why do men sleep around? To make sure their genes survive. Why are men faithful? To make sure that their babies grow up and survive. You can have it blue, black, any colour you want, and with raspberry stripes.

The technology of the human genome, heck, the technology of the fruit-fly genome, is probably going to turn out to be an even bigger mess than the codebase of Windows Vista. In the end we will need good, old-fashioned stories. The reason that there are a great many natural blondes in Newcastle has nothing to do with nightclubs and evolution. It has to do with genes and marauding Nordics back in the day. That's a story we can understand. Evolution will vanish like a puff of smoke the moment we have a decent understanding of the gene and the latest crop of alpha academics can popularise it (which will mean all those silly names for genes will have to go) with a few nifty diagrams.

Fodor and Piattelli-Palmarini recognise the very different attitudes between the hard-core scientists working around genetics and inheritance, and the pop science authors of the potboilers. What they miss is a decent structure: starting the essay with a whole mass of sound bites from the Pop Guys to convince us that there really were people who think like that. Then they could have explained the difference between the Pop Guys and the Real Scientists, not least the fact that the two work in very different disciplines, only one of which requires lots of specialised knowledge, and run through the fascinating stuff that the real scientists have done. (You can make a fruit fly grow a stubby set of wings by exposing it to ether when young. Do this for a few generations and the stubby-wing gene stays put. Last time I learned genetics, the genotype had to be inviolable by the outside world, or you had Lamarkianism, which was like Gnosticism but more serious.) The reader will then be on board with the idea that genetic change is way more complicated than simple random variation. Instead of burdening us all with the idea of "intentional agency", they could have just pointed out but less flippantly, that if we are "selecting for fitness", we're doing it very badly, or "fitness" has nothing to do with what it takes to get ahead in any man-made environment. Explain that the real attraction of Evolution is that it is conventional history, and helps us make sense of a very diverse world in a way that we're used to. There will be very few left on the Pop Train by this point.

It hurts anyone's case to be rude about the opposition. At this point they need to explain what's good in the Pop books, and what is rhapsody. Merely to list the sales figures of the top Evo potboilers would make the point: everyone would instantly understand that it couldn't be real science, because that many people don't understand that much science. A brief tour round the sociology of the Evo community: the superstars, the sales, the institutions and their funding, the numbers of academics, and therefore wives and families, supported by the Pop stuff, and we're done. That gets them into trouble with their mates, sorry, peers, but the general reader knows it's all about the money, it's just that in academia, it's hard to see where the money is.

All that's lurking is the readers fear that if we abandon Evolution we will all have to go to Church on Sunday. Wearing black suits. In buggies. They could deal with that by pointing out that there is a perfectly acceptable non-Creationist alternative to Evolution, which is genetics + inheritance + falling in love and having babies. They will have laid the foundations for that in the earlier chapters. And they can point out, and rightly, that there is no need for a universal mechanism to explain species change, any more than there is a need for an universal mechanism to explain regime change throughout history.

Which then leaves the final chapter, which makes them hot sellers: that's the one called "Evo Porn". This is where they quote some juicy passages where Evo is used to "explain" human behaviour, and then have some fun explaining why this has nothing to do with Darwin, Dawkins or even Cronin. The general reader will be left both titillated and with the impression that the Pop writers are really a bit ridiculous.

And having thought it through like that, I can think of another sub-title: never send an epistemologist to do a methodologist's job.

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