Is Natural Selection a Tautology?

By Jason Rosenhouse

As I write this, Ann Coulter's new book Godless: The Church of Liberalism is currently number one on the New York Times bestseller list. The book contains four chapters dealing with evolution. In these chapters Coulter, well known for her right-wing polemics, attempts to portray evolution as nothing more than a sham science that serves as a creation myth for political liberals. Reading this material is a curious experience for anyone who knows some freshman biology. As with all anti-evolution writing, the arguments that are presented are not only incorrect, but also so confused that it is frequently difficult to discern what point Coulter thinks she is making.

The present essay will be devoted to just one of the arguments upon which Coulter bases her case. The motivation for this series of essays has always been a desire to use insipid creationist prattle as a tool for promoting clear thinking about basic biological questions. It is hoped that by thinking carefully about why Coulter’s caricature of evolutionary biology is wrong, one can come to better understand the real thing.

The argument in question is sometimes referred to simply as The Tautology Objection. Coulter's version goes like this:

The second prong of Darwin’s “theory” is generally nothing but a circular statement: Through the process of natural selection, the “fittest” survive. Who are the “fittest”? The ones who survive! Why look it happens every time! The “survival of the fittest” would be a joke if it weren’t part of the belief system of a fanatical cult infesting the Scientific Community.

The beauty of having a scientific theory that’s a tautology is that it can’t be disproved. Evolution cultists denounce “Creation Science” on the grounds that it’s not “science” because it can’t be observed or empirically tested in a laboratory. Guess what else can’t be observed or empirically tested? Evolution! (pp. 212-213).

Writing in National Review Online in December of last year, conservative commentator Tom Bethell expressed the main point more clearly:

Darwin's claim to fame was his discovery of a mechanism of evolution; he accepted “survival of the fittest” as a good summary of his natural-selection theory. But which ones are the fittest? The ones that survive. There is no criterion of fitness that is independent of survival. Whatever happens, it is the “fittest” that survive — by definition. (Emphasis Added)

Even before considering the minutiae of how fitness is defined, we should note something suspicious about this argument. Coulter and Bethell are not saying here that recent discoveries have shown that evolution is an inadequate theory. Rather, they accuse scientists of having made a simple logical oversight. Paleontologist Stephen Jay Gould observed (in response to a previous article, in Harper’s Magazine, in which Bethell raised the same issue):

Bethell’s argument has a curious ring for most practicing scientists. We are always ready to watch a theory fall under the impact of new data, but we do not expect a great and influential theory to collapse from a logical error in its formulation.

Indeed. Scientists are fully capable of jumping to conclusions, or arriving at incorrect theories from an inadequate supply of data. But it has never once happened in the history of science that a theory achieves mainstream status, only to fall apart when a clever outsider notices a simple logical oversight. That Coulter’s and Bethell’s formulation of evolution suggests it is tautological proves only that they do not understand the theory they are attacking (or are deliberately misrepresenting it, but we will leave aside that possibility for now).

Let us begin our reply to this argument in the most direct way possible. It is asserted that within evolutionary theory, the fittest organisms are defined as those who survive. This is the crux of the argument, and it is completely incorrect. In reality, the fittest organisms are the ones who, based on their physical characteristics and the environment in which they find themselves, would be expected to leave the most offspring. Gould described the point this way:

My defense of Darwin is neither startling, novel, nor profound. I merely assert that Darwin was justified in analogizing natural selection with animal breeding. In artificial selection, a breeder's desire represents a “change of environment” for a population. In this new environment, certain traits are superior a priori; (they surive and spread by our breeder's choice, but this is a result of their fitness, not a definition of it). In nature, Darwinian evolution is also a response to changing environments. Now, the key point: certain morphological, physiological and behvioral traits should be superior a priori as designs for living in new environments. These traits confer fitness by an engineer's criterion of good design, not by the empirical fact of their survival and spread. It got colder before the wooly mammoth evolved its shaggy coat.

To read More of This Article Visit:Â

http://www.csicop.org/intelligentdesignwatch/tautology.html

To read More Columns by Dr. Rosenhouse Visit:

http://www.csicop.org/intelligentdesignwatch/rosenhouse.html