Celebrating Darwin Day by Correcting Michael Behe on the Evolution of Polar Bears

This guest post by Nathan Lents is cross-posted from The Human Evolution Blog. It was co-authored with Arthur Hunt of the University of Kentucky, who first pointed out some of these errors on the Peaceful Science forum. I wish I had spotted these myself before Richard Lenski, Josh Swamidass, and I wrote our review for Science, but I took Behe's word on the polar bears because it all sounded solid. In other words, I did what Behe hopes all his readers will do - just believe him and not check the reference. Lesson learned, and kudos to Art for catching this and for working with me on this post. Matt Young is the moderator of the post on PT. We have discussed the Science review here

The release of Michael J. Behe’s newest book, Darwin Devolves: The New Science About DNA That Challenges Evolution, is nearly upon us and so the first chapter was made publicly available to entice readers. In this chapter, Behe outlines his main thesis: at the molecular level, adaptive changes are largely due to events that in some way destroy or damage proteins and enzymes. He calls it the first rule of adaptive evolution and to illustrate his point, he discusses the evolution of polar bears and describes the molecular events in that evolution as nothing more than a series of damaging mutations that result in a more adapted organism.


But first, a quick introduction to Behe for those who may not know who Behe is or where this is coming from. With the release of his first book, Darwin’s Black Box, in 1996, Behe helped revolutionize and reorganize the resistance to modern evolution under the banner known as “Intelligent Design,” often abbreviated as ID. Many consider ID as simply creationism by another name, but the ID community works hard to distance themselves from that label. They insist that ID is a scientific theory, not a religious one, based on what they consider evidence that cells and organisms were designed intentionally, rather than the result of the aimless and unguided forces of evolution. Scientists and federal courts disagree, but this has not stopped the steamroller of pseudoscientific claims from the ID community.

Six Darwin Day facts from Pew

Charles Darwin
Charles Darwin in the 1830's. Wikimedia, public domain.

Tomorrow, February 12, is Darwin Day, and David Masci of the Pew Research Center has very conveniently come out with 6 facts about the evolution debate. You could quibble with his failure to use scare quotes over the term debate, but his facts are to some extent comforting. A sampling of these facts:

Fact 1. Approximately 80 % of US adults say that “humans have evolved over time.” About half of US adults think that God or someone else guided the process, which is frankly not an inherently anti-scientific position. About 20 % of US adults think that humans have always existed their present form; that is, of course, true, because before they evolved to their present form they were not humans.

Fact 3. Approximately 75 % of US adults recognize that biologists think that “humans have evolved over time due to processes such as natural selection.” Those who reject evolution, by contrast, are split roughly 50-50 on whether most biologists actually think that humans have evolved. In fact, 98 % of AAAS biologists agree that humans have evolved over time.

Fact 5. Those who are religiously observant are less likely to find that science and religion are in conflict. Two-thirds think that their own “religious beliefs do not clash with accepted scientific doctrine.”

Behe devolves


Creationist Michael Behe is at it again. (Professor Behe is the originator of the claim that certain structures could not have evolved by random mutation because they are irreducibly complex. We have reviewed his works many times on The Panda’s Thumb; a small sample, here, here, and here.)

Professor Behe’s latest effort is evidently a book entitled Darwin Devolves and subtitled “The New Science about DNA That Challenges Evolution.” I have not read the book and probably will not. I have, however, come across a review by Nathan H. Lents of John Jay College, S. Joshua Swamidass of Washington University in St. Louis, and Richard E. Lenski of Michigan State University. Professor Lenski, in particular, is noted for incubating bacteria for 25 years (as of 2013) and watching them mutate. We described his experiment briefly here. The experiment shows, according to an article by Elizabeth Pennisi in Science magazine, “how multiple small mutations can prepare the ground for a major change,” among other things. Professor Behe essentially denies this conclusion.

The review of Darwin Devolves is highly critical, if not downright scathing. According to the review, Prof. Behe claims (consistently with other creationists) that evolution can progress unaided only by degradation or loss of function. He then discusses Prof. Lenski’s experiment and dismisses it. He “ignores the fact that some of his prior arguments have been dismantled.” In particular, he continues to claim that the blood-clotting complex is irreducible, when it has been shown not to be irreducible. He “doubles down” on his spurious claim that chloroquine resistance by the malaria parasite cannot have evolved by random mutation. And finally he evidently completely ignores exaptation, wherein a structure previously used for one purpose is adapted to another. Instead, he argues

that new functions only arise through “purposeful design” of new genetic information, a claim that cannot be tested. By contrast, modern evolutionary theory 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.

Ultimately, Darwin Devolves fails to challenge modern evolutionary science because, once again, Behe does not fully engage with it. He misrepresents theory and avoids evidence that challenges him.

Speaking of devolving, I can only add that Profs. Lents, Swamidass, and Lenski have made a monkey of Prof. Behe.

Total eclipse of the moon


I think I have waited at least since I was 10 y old (never mind how long ago that was) to see a total eclipse of the moon. I finally saw a good one the other day and did not even have to squander my grandson’s inheritance to see it. Instead, I took my camera and a tripod and went into the back yard. Despite the approximately 1 h of totality, the eclipse was much harder than the solar eclipse, in part because the camera did not autofocus on such a dim image. At any rate, I set the camera to exposure bracketing and F/8, ISO 200 except during totality, and went at it, with the following result.

Lunar eclipse
Total eclipse of the moon, approximately 8:30-12:00 MST, January 20, 2019.

Acknowledgement: Once again Fred Espenak’s exposure guide was invaluable and saved a lot of fiddling.