An Adaptationist View of Stephen Jay Gould

 
In last week's issue of Nature, Steve Jones reviews Stephen Jay Gould: Reflections on His View of Life. Jones is part of the British school of Darwinism, along with Richard Dawkins, the late John Maynard Smith, and others.¹ This group shares many perspectives on evolutionary theory including an emphasis on natural selection. They are also united in their dislike of, and misunderstanding of, Stephen Jay Gould.

The misunderstanding shows up in several places in the Jones review [A wonderful life by leaps and bounds].

Being part of the anti-Gould school means that Jones is obliged to trot out the famous quotation by Maynard Smith (it's part of their oath of allegiance).

Gould held fast to Darwin's maxim that "All observation must be for or against some view if it is to be of any service", and was among that band who felt that those not for him must be against him — which was not much help in keeping friends. The great biologist John Maynard Smith wrote that most evolutionists saw Gould as "a man whose ideas are so confused as to be hardly worth bothering with, but as one who should not be publicly criticized because at least he is on our side against the creationists".

Gould was hurt by that acidulous statement, which was without doubt unfair.

Of course it was unfair—so why repeat it? The statement says more about the British Darwinists than about Gould. The fact that they find Gould's ideas "confusing" isn't something to be proud of.

One of Gould's major contributions to evolutionary theory was punctuated equilbiria, with Niles Eldredge. The basic idea is that the fossil record shows millions of years of stasis (no change) and when change occurs it takes place relatively quickly during speciation by cladogenesis (splitting). After that, the two species (parent and daughter) continue to exist together in the same environment.

The morphological changes that occur when a new species is formed are not dramatic. They are similar to the differences between closely related modern species. In many cases it takes an expert to even recognize the new species in the fossil record.

Punctuated equilibrium is a theory of speciation and stasis. The changes during speciation may be due to natural selection or some form of random genetic drift. That's not what's important about punctuated equilbria—what's important is that change is coupled to speciation and nothing happens for most of the life of a species.

Here's what Steve Jones has to say about it.

Whatever the importance of sudden leaps in the fossil record, his notorious idea of punctuated equilibria, nicknamed 'punk eek' and referred to as 'evolution by jerks' by some of its critics — their own views characterized by Gould as "evolution by creeps" — gave the fossilized field of palaeontology a much-needed kick in the pants. Gould saw punk eek as a "coordinating centrepiece" that "congealed into a coherent critique" of evolutionary theory. Many biologists, by contrast, insist that what look like palaeontological leaps can be explained by simple Darwinism. To them, an instant in geology may represent almost an infinity in biology, leaving plenty of time for evolution by natural selection to do its normal job.

He just doesn't get it, does he? The speciation event takes place over a period of about one hundred thousand years as Gould and Eldredge explained. That's plenty of time for selection, or drift, or founder effect, or whatever. Punctuated equilibria is not a challenge to natural selection, it's a challenge to gradualism.

Furthermore, anyone who refers to punctuated equilibria as "sudden leaps" is revealing an understanding of the theory that's no better than that of the creationists. As is anyone who thinks that "Darwinism" explains speciation.

His other great passion, contingency — the notion that evolution goes on with sudden bangs rather than protracted whimpers — has also not held up particularly well. Wonderful Life, Gould's 1989 book on the Burgess Shale, suggests that the obscure fauna of the late pre-Cambrian represents a lost universe wiped out by some unknown disaster, but now we know that they have descendants among modern animals. Even so, scientific ideas often change, and that volume, like most of his others, remains a rattling good read. The fact that nature must build on what it has, and not on what it wants, is still at the centre of evolutionary thinking.

Talk about confused thinking! When did Gould ever say that contingency is "the notion that evolution goes on with sudden bangs"?

Gould and Lewontin made great play with the parallels between the Spandrel School and the many evolutionists who say that every character in every animal is there for an adaptive reason and if you look hard enough you'll find it.

There's some truth in their argument, but to accept it as the only truth is basically to give up and walk away, to stop being an ornithologist and turn into a bird-watcher. You become somebody who observes rather than analyzes. What they're saying to lots of biologists is, "Abandon hope, go home, and become a liberal-arts graduate!" I may be overcriticizing the Lewontin and Gould view; both of them like to poke people with their sharp pitchforks. The spandrels were a particularly successful poke. But what happened as a result of the famous spandrel paper? The answer is, not much.

Steve Jones in
The Third CultureAs for Wonderful Life, it is, indeed, a book about contingency—just like the movie from which it takes its title. One wonders whether Steve Jones has actually read the book, or seen the movie.

While it's true that some of the unusual Cambrian species that Gould once thought were separate phyla have now been lumped into modern phyla, it's also true that there are many that haven't. Gould's point is that some of those enigmatic Burgess Shale species have left no descendants and, if you could have observed them back then, you would not have been able to pick out the eventual winners and losers. In other words, if you re-wind and replay the tape of life it will come out differently.

Jones is not referring to these species however. He's talking about the "pre-Cambrian" fauna—presumably the Ediacara biota. It's not an important part of Gould's book. As far as I know the relationship between Ediacaran species and modern species is still very controversial. Perhaps Jones has studied this in more detail that I have.

One of the ideas to come out of punctuated equilibria is the idea of species sorting. This makes sense when you think about it. If most speciation occurs by cladogenesis and not by gradual transformation, then over time the number of species in a clade doubles every five to ten million years. Eventually there will be hundreds of similar species. The reason this doesn't happen is that species go extinct. They die.

If species within a clade are "born" and "die" then this looks an awful lot like evolution at a different scale than the birth and death of individuals within a population. The idea of species sorting, where the species in a clade are treated like the individuals within a population, is part of Gould's hierarchical theory of evolution. He claims that it is an extension of the Modern Synthesis.

Whether he's right or wrong doesn't matter. What matters is whether his critics have the intelligence to understand hierarchical theory in general, or species sorting in particular. I don't have much respect for evolutionists who refuse make a modest attempt to understand; it's not rocket science.

Here's what Steve Jones says.

Backwards ran his sentences, and some of his ideas were equally opaque. In support of punk eek, for example, he wrote that "species are individuals ... by all vernacular criteria", which is at best obscure, and at worst obscurantist.

No, Professor Jones, it is not obscure and it is not obscurantist. Gould explains it very well to those who can read his works with an open and intelligent mind. He's talking about species sorting and treating species as "individuals" that are selected within a clade.

As Reflections portrays, its hero showed an increasing regard for style over content, and was resistant to the notion that anyone should dare to edit his writings. The pinnacle — the very summit, crown and peak — of his great Olympus of orotundity was his last voluminous volume, The Structure of Evolutionary Theory, published in the year of his death. All the authors agree that this is not a book to be lightly tossed aside, but their motives for saying so vary. Its reviews are quoted with a certain relish: "an elephantine opus"; "pathological logorrhea"; "billowing clouds of verbal flatulence" — but Gould had no doubt of its value. In it he came out with the idea of life as a series of interlocking hierarchies and of a grand unification of its sciences into some post-Darwinian consilience, comprehensible only to the chosen.

The Structure of Evolutionary Theory is long and tedious but those who criticize its ideas are the ones who confuse style over content. I don't agree with many of Gould's ideas about species sorting and hierarchical theory and therefore I stand as the exception to Steve Jone's claim. It was comprehensible to this unchosen one so it must also be comprehensible to others who disagree with Gould. You just have to make the effort.

If you don't make the effort to understand Gould then you should refrain from criticizing him. It doesn't make you look good.

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1. For examples of the Steve Jones perspective on evolution see Have Humans Stopped Evolving? and Steve Jones Says Human Evolution Is Over.

[Image Credit: The Cheltenham Ladies' College]