Molecular Evolution Activities

Ideology, and Other Issues Transcript

The Role of Ideology, or Values, or Otherwise Extra-Empirical Issues in the Neutralist-Selectionist Controversies.


Richard Lewontin: A topic that I would like to see discussed is ideology. I think it's very important.

John Beatty: Could you give us a hypothesis about the way that ideology enters in?

Lewontin: Well, I think there are people committed to—and more now than ever—to an optimality view of evolution, to a functional view that everything is the best of all possible worlds. And that has a powerful effect on views of neutrality.

Ford Doolittle: Genomics is based on that view. There's lots of money dependent on a hyperadaptationist view. I think this naturally segues into a discussion of neutrality, optimality, function at all different levels. It has never received rigorous, philosophical attention.

Beatty: I think I see where you're going, but just to clarify, can you articulate the way in which optimality represents an interest of people who have particular positions in these debates, or how optimality represents an interest within genomics?

Doolittle: We were discussing it earlier in connection with junk DNA. Do organisms with four times as much DNA need four times as much DNA? Were introns really introduced in order to increase the flexibility of evolution? There are many levels of selection involved here. I believe introns do increase the flexibility of evolution, but I don't believe that they were introduced into a population because they would have that effect. These things are not discussed carefully, theoretically, but they are always the subtext of what we do, and particularly in molecular evolution. This is certainly the case in the evolution of molecules; for example, in the case of RNA editing, which I think is junk piled on top of junk, ratcheting itself to inevitability. But many molecular biologists believe that selection created this wonderful stuff. There is a very strong selectionist, panadaptationist view of molecular biology and genomics. There are millions of dollars to sequence genomes, and of course they don't like to hear that most of that is really junk. There was an article in the last issue of Science to the effect that, maybe all those insertion sequences are really there for a purpose. It's very mystical.

James Crow: I've always found it really surprising that molecular biologists can be such panselectionists, though I don't mean to tarnish the whole field.

Doolittle: But at the same time they accept neutrality at the molecular sequence level, and always have. So it's very interesting.

William Provine: There is an element that goes with ideology, namely, aesthetics. The really beautiful things are deeply attractive to practically everyone. Kimura hated the idea that his beautiful neutral theory would have to be modified to nearly neutral. He hated it. He resisted it.

Lewontin: Because it wasn't clean, you mean?

Provine: Not clean at all! It doesn't have that ??? to it. He wanted it to be beautiful. And when he was able, he did it. In the 1983 book, he's got a horribly complex gamma distribution version of the nearly neutral theory, and he's got the completely neutral theory. Two years later, with the DNA sequence data, he's gone back to his completely neutral model. And is he happy with that? His papers just exude happiness in 1985 and 86 because he's back where he wanted to be. And he's confident. It's beautiful to see it. And this is an aesthetic preference.

Lewontin: Would you accept an amendment? The word "aesthetic" bothers me a little. I think it's a little different. To call it "aesthetic" removes it from an historical perspective. The ideal that I was taught as a high school student of what a science is, and that Motoo learned, and that we all learned [pounds table]—who embodied that ideal?

George Smith: [immediately] Newton.

Lewontin: That is to say, the more general, the more neat, the more succinct the law is, the greater the science, and we're all trying to be Newtons. Motoo was trying to be the Newton of biology and evolution. And if you have to say, "No, it's not so simple; look at the second volume of the Principia instead of the first volume, where Newton says that there are real objects moving in a fluid, and there's friction, and it really doesn't work the way the first law says"—you know—that's biology. So I think that it's not an aesthetic issue, but an issue of the formation of intellectuals in the natural sciences, that the ideal is to have it all be...

Crow: [finishing Lewontin's sentence] simple. It's simplicity rather than aesthetics.

Provine: Kimura was intensely aware of Fisher's attempt to go from laws of gases to natural selection.

Lewontin: But that's not aesthetics. Who is the greatest scientist who ever lived, who made a generalization that applies to everything?

Michael Dietrich: But when Gillespie states the selectionist challenge, he puts it in aesthetic terms. He says the big challenge is to produce a selectionist theory that is "as elegant" mathematically.

Lewontin: But don't call it "aesthetic," because that suggests the origin of it outside of a very important cultural historical phenomenon, which is the training of scientists and the ideological formation of scientists with regard to what it is to be a scientist. I think that's the issue.

Provine: I would still argue that aesthetics is important.... For the generation of hypotheses, I think aesthetics is incredibly important. But when it's used to discriminate between hypotheses, it falls on its butt. That's where aesthetics has a real problem. But in the generation of theories, I would still argue that there is an element of beauty that people do care about.

Smith: [Smith is a Newton scholar] I'm tempted to make a comment about Newton, but maybe it's best if I didn't.

Lewontin: It's the ideal Newton we're interested in. [laughter]

Beatty: Yeah, what Newton really said is unimportant. [laughter]

Smith: Newton, before he started writing the Principia, was convinced that the actual motions of the planets were beyond human reckoning. And what he saw was that this simple tool could allow further investigation, and that that further investigation could then complicate the initial theory in a way that would be empirically driven rather than a matter of mere hypothesis. So it's a very sophisticated picture of why simplicity is good, because it's going to promote more effective empirical inquiry over the long run.

Beatty: We've talked about a number of different reasons why people were attracted to the neutral theory: partly because it was Newtonian, or because it was elegant. Other people have used the term "tractability" to refer to kind of the same thing. Maybe we can talk about all these as "extra-empirical" factors that help explain why people were attracted to the neutral theory. But I would like for Dick to say something about what he meant by "ideological" commitments to natural selection and optimality. Ford cashed it out in terms of the value of genomics depending on not everything being junk DNA—he even mentioned the monetary value of the field.

Lewontin: I'm not sure any more. I once would have said that those different ideologies came out of social and political worldviews. But I'm no longer convinced of that. I wouldn't want to defend that claim. I would want to defend the claim that there are persons for whom it does come down to that. But it seems to me not true that one should attempt that reduction. I think when I look around at commitments to optimality, for instance, I see they cover a lot of people and territories that have no obvious connection. So, for the foolishness of my youth, I'm not responsible. But it's still ideological. I don't want to restrict the term "ideology" to politics.

[For an example of Lewontin's earlier view, see this 1973 video clip]

Crow: You know, Haldane insisted that Marxist philosophy had a great influence on his science, but I'm not sure that it did.

Lewontin: No, and in fact the last speech that he gave, at the last Congress of Genetics in the Hague, was the most un-Marxist, reactionary piece I've ever heard.

Dietrich: Dick, in your 1974 book, you talk about how ideology functions….

Lewontin: Let me repeat my simplistic view of the life of Dobzhansky. Dobzhansky started out life studying beetles in central Asia. He was incredibly impressed with their diversity: more than he could cope with. And his whole life was devoted to the claim that, not only was there a tremendous amount of diversity in populations, but that that diversity was a good thing. And he said over and over and over again that diversity per se is adaptive and good. And he and I used to have terrible fights about that. That's what I would call "scientific ideology." His whole life was informed by the view that polymorphism in the broadest sense was a virtue, and the problem with inbred populations was that they were all uniform. There are all those papers on how homozygotes are "narrow specialists" and heterozygotes are "broad generalists." He even argued that the worst thing in the world was not to be homeostatic. You want to be homeostatic, which means that you don't want to respond too much to the environment. So I used to say to Dobzhansky, "That's crazy, because on your conception of homeostasis, an unconditional lethal is the most homeostatic genotype there is. Because irrespective of the environment, it always shows the same phenotype, namely it's dead." And he would say, "Oh this fellow Lewontin is crazy. He thinks that lethals are homeostatic." And that wasn't the point.

Dietrich: In your book you say that ideology drives the controversy and prevents resolution.

Lewontin: Well, I'll stick to that.

Beatty: Maybe one way to pose the question about ideology in the neutralist-selectionist controversies is to contrast those controversies, just for the sake of discussion, with the classical-balance controversy. Because among the multiple sources of the neutralist-selectionist debate is probably the classical-balance debate, in which, I think a lot of people would agree, ideology played a role.

Lewontin: Although in very subtle ways, John. For example, the last time I had a fight with Dobzhansky, just before he died, I accused him of being a biological determinist. And he hated that. I said "You're as much of a biological determinist as Hermann Muller was. It's just that you think the heterozygotes are the most wonderful thing, and he thinks the homozygotes are." But they were both biological determinists. And I think that was a supervening ideology.

Crow: And if we hadn't had this debate about nuclear testing going on, it probably would have been a different kind of debate, I think. So it really was political in a very ordinary sense.

Lewontin: I think that's also very interesting.

Beatty: So my question is, could a debate that had such a rich ideological, social and political context be the source of a debate that has no ideological, social and political context?

Crow and Lewontin: Good question.

Beatty: It's not at all apparent to me what the social context of the neutralist-selectionist controversy is. They seem highly technical. But maybe it's just because I've been living through them, and it's hard to see where you're coming from when you're there.

Lewontin: It might be more a question of who takes up one side or the other.

Jan Sapp: Back to this word "ideology." Within the neutralist-selectionist debate, we certainly can see an ideology of "disciplinary interests." As Mike Dietrich talks about, the disciplinary interests of those working at the macro scales had different interests than those working at the molecular levels. Take, for example, the interests of Mayr and Simpson and Dobzhansky to protect the theories of the synthesis. To put it another way, if molecular evolutionists were not neutralists, there would still have been a controversy. The fact that they were neutralists just exacerbates the controversy. It's an issue of interlopers, the molecular biologists, changing the direction of evolutionary biology and the way in which one does biology. And I think these are matter of—I don't know—ideology, in the sense that they involve disciplinary interests and social interests.


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