Is Evolution a fact?

In 1986 Stephen Jay Gould assured a group of New Zealanders that they had nothing to fear from Creationism. It was, he said, a distinctively American aberration--a case of negative exceptionalism. The rest of the advanced industrial world was much wiser.

Unfortunately that has not proved to be the case. Per capita, there are almost as many Creationists in Canada than in the US. The movement has been successfully transplanted to Australia, New Zealand, and Great Britain. It has been making great strides in Switzerland, Austria, Germany, and the Netherlands. One science writer in Amsterdam asks, “Is Holland becoming the Kansas of Europe?” South Korea represents a major bridgehead in Asia. And Turkey is now a major center for the spread of this knownothingism in Islamic countries.

This deplorable export parallels the flood of American products in popular culture: rock, rap, and heavy metal music; “action” movies featuring violent confrontations; and TV soap operas. Still, these things are offences to taste, but not to reason, as Creationism is.

All the same, there is evidence that some scientifically minded observers are overreacting, or reacting in a way that is counterproductive. One can understand how frustration at the advance of Creationism would produce sharp responses among the defenders of the scientific theory of evolution. Indeed, it must be defended. However, some excesses on part of the pro-evolution camp make them vulnerable to criticism.

Jerry Coyne is a professor at the University of Chicago in the Department of Ecology and Evolution. He is an energetic defender of evolution. Yet he has just published a book entitled “Why Evolution is True” (Viking), where he asserts that evolution is more than just a theory--it is a fact. These assertions have an air of dogmatism that is not helpful. Recently, in the columns of The Nation Coyne heatedly attacked Robert Wright’s book “The Evolution of God,” for being soft on the deity question. Now there are many problems with Wright’s argument as I have pointed out in two previous postings. Yet he does not actually affirm the existence of God; he is an agnostic. This is not enough for Coyne. Besides, Wright has taken the sacred name of evolution in vain, kidnapping it for his own theory. Coyne does not seem to realize that there is an ordinary use of the word evolution, which existed long before Darwin, to describe any orderly process. Thus one can speak of the evolution of the US Supreme Court and the evolution of classical studies.

Now the ubiquitous Richard Dawkins has weighed in with a new book “The Greatest Show on Earth: The Evidence for Evolution” (Free Press).

In his review in today’s New York Times Book Review, Nicholas Wade, a science reporter for The Times, salutes the worthiness of Dawkins’ effort to discredit the Creationists. Yet he also makes some telling points about the line of argument the English scholar deploys.

“There is one point on which I believe Dawkins gets tripped up by his zeal. To refute the creationists, who like to dismiss evolution as “just a theory,” he keeps insisting that evolution is an undeniable fact. A moment’s reflection reveals the problem: We don’t speak of Darwin’s fact of evolution. So is evolution a fact or a theory? On this question Dawkins, to use an English expression, gets his knickers in a twist.

“Evolutionary theory is a mansion that has been under vigorous construction for the last 150 years and is still far from complete. A ballroom-size controversy is whether natural selection can operate at the level of groups as well as that of individuals. The evolutionary theory of aging, which predicts that many genes must be involved in determining life span, recently collapsed when researchers found that the lifetimes of laboratory organisms can be tripled or better by changing a single gene. If the theory of evolution is still in full flux — as befits any scientific theory at the forefront of research — how can evolution be said to be a fact?

“Dawkins is aware that evolution is commonly called a theory but deems “theory” too wishy-washy a term because it connotes the idea of hypothesis. Evolution, in Dawkins’s view, is a concept as bulletproof as a mathematical theorem, even though it can’t be proved by rigorous logical proofs. He seems to have little appreciation for the cognitive structure of science. Philosophers of science, who are the arbiters of such issues, say science consists largely of facts, laws and theories. The facts are the facts, the laws summarize the regularities in the facts, and the theories explain the laws. Evolution can fall into only one of these categories, and it’s a theory.

“Other systems of thought, like religion, are founded on immutable dogma, whereas science changes to accommodate new knowledge. So what part of science is it that changes during intellectual revolutions? Not the facts, one hopes, or the laws. It’s the highest-level elements in the cognitive structure — the theories — that are sacrificed when fundamental change is needed. Ptolemaic theory yielded when astronomers found that Copernicus’s better explained the observations; Newton’s theory of gravitation turned out to be a special case of Einstein’s.
“If a theory by nature is liable to change, it cannot be considered absolutely true. A theory, however strongly you believe in it, inherently holds a small question mark. The minute you erase the question mark, you’ve got yourself a dogma.

“Since the theory of evolution explains and is in turn supported by all the known facts of biology, it can be regarded as seriously robust. There’s no present reason to think it has any flaws. But when we learn how life evolved on other planets, evolution could turn out to be a special case of some more general theory.

“When Dawkins asserts that evolution “is a fact in the same sense as it is a fact that Paris is in the Northern Hemisphere,” it seems he doesn’t know what a theory is. Yet he is justified in his passion to demonstrate how beautifully the theory of evolution explains the biological world. How can his knickers be untwisted?

“The best way, in my view, is to distinguish between evolution as history and evolution as science. Evolution is indeed a historical fact. Every living thing and every fossil-bearing rock bears evidence that evolution occurred. But evolution is not a scientific fact as philosophers of science see it. In science it plays a far grander role: it is the theory without which nothing in biology makes sense. The condition of this high status is that it cannot be the final and absolute truth that Dawkins imagines it to be; it is liable to future modification and change like any other scientific theory.

“This brings me to the intellectual flaw, or maybe it’s a fault just of tone, in Dawkins’s otherwise eloquent paean to evolution: he has let himself slip into being as dogmatic as his opponents. He has become the Savonarola of science, condemning the doubters of evolution as “history-­deniers” who are “worse than ignorant” and “deluded to the point of perversity.” This is not the language of science, or civility. Creationists insist evolution is only a theory, Dawkins that it’s only a fact. Neither claim is correct.”