Defending Darwin: Scientists Respond to Attack on Evolution

Science magazine, the country’s top scientific journal, has taken the rare step of publishing criticism of a new book. The book is called Darwin Devolves, and Science says its author, Michael Behe, is on a “crusade to overturn evolution.”

The magazine invited three biologists, all experts on evolution, to refute Behe. The biologists are John Jay College Professor Nathan H. Lents, a noted researcher on cell and cancer biology, genetics, and forensic science; Washington University Professor S. Joshua Swamidass, a physician-scientist; and Michigan State Professor Richard E. Lenski, a member of the National Academy of Sciences and a past MacArthur “genius” fellow.

Behe, a biochemist, is a leader in the “intelligent design” movement, which contends that living organisms are too complex to have evolved on their own. The claim is cited by some as proof that a supernatural force has designed all living things.

Lents and his colleagues discredit Behe in elaborate detail, noting that he’s “selective” in his examples and ignores evidence contradicting his theories. Modern evolutionary theory, the authors write, “provides a coherent set of processes — mutation, recombination, drift, and selection — that can be observed in the laboratory and modeled mathematically and are consistent with the fossil record and comparative genomics.” In contrast, “Behe’s assertion that ‘purposeful design’ comes from an influx of new genetic information cannot be tested through science.”

Darwin Devolves is being released at a time when science in the U.S. is under assault. Unfounded fear of vaccines has led to measles epidemics. Climate change is causing irreversible damage. And the proper teaching of evolutionary science is being undermined by local school boards. By publishing a response to Darwin Devolves in the flagship journal of the American Association for the Advancement of Science, the AAAS is signaling its willingness to call out pseudoscience and defend the facts supported by scientific research.

Behe is known for the notion of “irreducible complexity.” He argues that “some biomolecular structures could not have evolved because their functionality requires interacting parts, the removal of any one of which renders the entire apparatus defective,” according to the Science article. But Lents and his co-authors explain that “irreducible complexity” is refuted by the evolutionary process of exaptation, in which “the loss of one function can lead to gain of another.”

Whales, for example, “lost their ability to walk on land as their front limbs evolved into flippers,” but flippers “proved advantageous in the long run.” Nature’s retooling of a biomolecular structure for a new purpose can lead to “the false impression of irreducible complexity.”

Of course, evolutionary theory has been challenged by non-scientific arguments since Charles Darwin published On the Origin of Species in 1859. Darwin Devolves continues this pseudoscientific tradition.