Stephen Jay Gould: Passionate Advocate for Evolutionary Biology

When I interviewed Stephen Jay Gould in his Soho apartment in New York City in 1996, he had written 263 of his 300 columns for Natural History magazine. Gould, who was born in 1942 and died of cancer in 2002, oscillated annually between being a professor of biology and geology at Harvard and working at the American Museum of Natural History. He had a wide-ranging, imposing intellect, a love for fashioning arguments and for debunking what he viewed as poor arguments. He had many roles, including being an explainer of evolutionary biology, an historian of science, and a baseball fan. He had a distaste for those he felt twisted evolutionary biology to evil or illogical purposes or tried to make evolution out to be a theory competing with divine creation, rather than as a fact. I spoke to Gould in his office, filled with autographed baseballs, Victorian books with marbled covers, and a rolling ladder so he could reach the upper shelves of his library. On a table sat an IBM typewriter which Gould wrote on. “I know what I want to say when I sit down to write,” he said. I interviewed him shortly after the publication of one of his books, Full House: The Spread of Excellence from Plato to Darwin.

What general impression of ideas in the book would you most like to stay in the minds of readers?

The general message is that you really need to look at something as fundamental and obvious as a trend in a very different way.  There are a hundred theories out there for why no one in baseball hits .400 anymore, but they are all backwards. Every one of them is based on the unquestioned assumption that .400 hitting is a thing that went away. Therefore, the assumption goes, it has to be interpreted as what went wrong with hitting. The other sophisticated version is that nothing went wrong with hitting it is just that pitching got better. But if you also you reconceptualize the problem and recognize that .400 hitting isn’t a thing, but it’s just an extreme value in the spectrum of variation of batting averages, then you have an alternative possibility. Namely, maybe the variation has contracted around a constant mean. 

I like the example and then I apply it to what most intellectuals would see as the bigger problem, the question of progress in the history of life. When you look at the full spectrum of variation, it really disappears and becomes a very different issue. The universality and the constancy of the bacterial mode emerges as the key phenomenon in the history of life. And if this report [of evidence of life on Mars] is true, then it’s probably life’s universal mode. It’s only rare that you’ll get a funny little right tail of complex organisms like us. 

What is your impression of the evidence for life on Mars?

It’s probably wrong, but it’s the best case they can make from the very limited evidence available. It gives them a case for going back up there and getting better evidence. I would be much happier with evidence that was intrinsic to the rock itself. They have not found fossils, they found chemical signs of what bacteria might produce. That is one step removed from a bone or a shell, which would be unambiguous. 

I felt slightly cheated by the book, only because seem to make the argument that progress is accidental. But nevertheless, progress does get locked in by evolution, so it seems inevitable.

It’s not inevitable, look at Mars. I suspect that most planets that evolve life don’t go beyond a bacterial mode. They sit there very happily and that’s fine. That’s most of life anyway, if you develop a right tail [of more complex organisms] yeah it locks in, but why would you want to see that—except that we like ourselves. You can’t confuse the impact of something with its historical inevitability. I don’t deny that the consciousness of one species has had a profound impact on the planet. But that doesn’t change the fact that it’s still one species, one lineage, out of millions and billions. Therefore, it’s a very curious result, it just happens to have occurred once with a profound influence on the planet. I think if you ran the story a hundred more times, you might get complexity often but I don’t think you would get self-conscious creatures arising very frequently. 

You’ve been accused of ignoring convergence. [The independent development of similar traits in unrelated or distantly related species.]

Of course I don’t. No evolutionary biologist ignores convergence.  But if you think about most convergences, first of all, a lot of classical convergence aren’t convergences. The work in developmental genetics has been making it clear in the last few years that a lot of them are parallelisms. Parallelisms are when you get similar phenomena arising in separate lineages because they share a common genetics. The eye is the classic case of convergence that turns out to be largely a parallelism in insects and vertebrates and probably cephalopods [such as squid and octopus]. Those three groups have developed complex lens-forming eyes and are all using the same genetic mechanisms. The eye itself is not homologous because they build them in different ways. But they’re using the same inherited genetic pathway from a common ancestry.

A bat and a bird and a pterosaur [an extinct flying reptile] are in some respects convergent in having wings. But the point is they are all vertebrates. You can only have the convergence because you have the underlying vertebrate design. They are convergences off a common ancestor of a multi-digited elongated pair of hands.

In the book you mentioned being fascinated by dinosaurs as a young person but I gather you think  they get more attention than they deserve.

They were the largest creatures on earth for a very long time, longer than mammals have dominated. There were certainly a lot of them and they are very interesting, but fundamentally, they’re one group of organisms. They capture fancy for a variety of reasons but they are not—contrary to the news reporting on paleontology—of equal intellectual importance to a major theoretical issue like whether there is life on Mars, what’s the cause of the Cambrian explosion, or why mass extinctions happen. The issue of whether dinosaurs were warm blooded, for example, doesn’t bear on any on any issue in evolutionary theory, it’s a particular question about some organisms that some people like. 

You’ve spent a lot of your career trying to educate people about evolution. How satisfied are you with the understanding that most people have of evolution? 

There’s Gallup poll results—but I don’t trust them—that seem to indicate that most people never think about evolution and don’t believe it, but I don’t really think those results are right. The question is always framed in polling in the light of creationist teaching in schools. If you ask most Americans about something they don’t care a lot about and ask them should you only teach this one thing or should you teach both things, there is a natural inclination—sort of a misplaced sense of fairness—to say teach both things. America is this weird nation that has maximal claims for religious affiliation and minimal religious participation. Most people have the sense they ought to say that humans were created by God because they remember it says so in Genesis. But I don’t think they are actively committed through theological analysis to these positions. The problem is that we’re not a well-educated society in general. If you ask the majority of Americans what the War of 1812 was all about, I think as few people could tell you about that as could tell you what evolution means. 

How much do you think the battle has been won against creationism? 

It’s entirely won in intellectual circles, but that’s been true for a century. In one sense creationism is out of the control of scholarly argument. Creationism recycles whenever you have a right-wing resurgence.  There are millions of creationists out there; they have a lot of money and they’re always there. They just seem very marginal in liberal ages and not so much so when they control conventions in San Diego.

Do you like anything in evolutionary psychology? 

I don’t like most of the specifics that the people who have christened themselves as evolutionary psychologists do.  I certainly like the idea that there should be a psychology informed by evolutionary theory. But what these self-proclaimed creators of a new discipline are doing is centrally wrong because they’ve got a dogma. 

They put forward the idea that universal human behaviors are genetically conditioned and are adaptations of our hunter-gatherer ancestors on the African savannas. Actually, it’s not a stupid argument. The problem is that it’s not testable. If you’re saying everything was adaptive when it first arose on the savanna, you can’t test this. You’re talking about small societies that even if we had the best fossil evidence in the world—which we don’t—there’s things you can’t learn about: their language or their social relations—that you absolutely have to know. You’ve essentially condemned the whole theory to untestability. Moreover, it’s a crazy theory. There are many things we do that are universal that are very vital to our current life, like reading, that can’t possibly be adaptive.

Many behaviors never were adaptations, they just arose as side consequences of building a big brain and then they were sitting there available for later utility. We read and write and compose operas not because we were designed to do that by evolution. It is a side consequence of a big, good brain

We may have built a large brain by natural selection—probably did—but that statement doesn’t allow [evolutionary psychologists] to interpret most of the universal behaviors they want to cite as adaptations.

I asked Daniel Dennett [philosopher and cognitive scientist, born 1942] why he spent so much time knocking your theories down while he was in the process of postulating his own.

What did he say, beyond jealousy? 

He said, basically, it was a preemptive strike.

Preemptive strike? Am I supposed to be after him or something?

He figured everybody would say “You have your evolution all wrong because you’re saying something different than Gould.”

He’s got some paranoid hang-up.

What do scientists miss when they focus just on the genetic level—and the idea that genes rather than organisms are competing against each other [gene selectionism]?

Gene selection is interesting. It’s helped focus a lot of thinking and it’s an intriguing way of looking at the world. The reason why it’s wrong, is that it has a central logical dilemma about it, which is more philosophical than scientific.  And that is, no one denies that natural selection usually works on organisms. Organisms live or die. The argument for Gene selectionism, as Dawkins puts it most dramatically, is that organisms are lumbering robots that they are just constructed by their genes and manipulated by their genes so that even though organisms live or die, it’s really in the service of genes.