Behe’s B-Cell Bravado, Part 3: Failure to Engage the Evidence
Many non-scientists are unaware of the importance or extent of “the scientific literature.” In the geeky world of science, success doesn’t depend on social prowess or earning power (thankfully!), but on one’s publication record. It’s hard to get published—to do so means making a significant contribution to the field, as judged by a panel of anonymous reviewers. Most people have nightmares about being chased or drowning. Scientists have nightmares about their papers getting rejected.
The main database for accessing the biomedical research papers, called PubMed, contains over 19 million articles. If you search PubMed for irreducible complexity, you’ll get 11 hits, none of which represents a peer-reviewed piece of work showing evidence of an Intelligent Designer. Most of the hits are commentaries on the Intelligent Design (ID) movement itself or attempts to “reduce” irreducible complexity. A couple of them are totally irrelevant.
Could this mysterious absence from the literature be a result of a conspiracy by Big Science to deliberately marginalize the work of people like Michael Behe? Though ID proponents often try to make this case (just watch Ben Stein’s Expelled), I think it’s very, very unlikely. But let’s give them the benefit of the doubt. If ID theory is scientific in nature, we can expect its leaders to engage scrupulously—as all scientists must—with the literature.
Unfortunately, Michael Behe does not have a great track record in this department. Consider his 1996 book Darwin’s Black Box. When reading the chapter on the immune system, for example, I kept expecting him to interact with the evidence for the gradual development of the antibody recombination system. The transposon hypothesis, which we examined in detail in Part 2, is a well-tested model for how this system could have originated. I couldn’t wait to see what Behe would say about it! His response was more than a little disappointing. He does refer to the model, at least indirectly, but only by discounting a two-page commentary—the purported “best efforts” in the field—as mere speculation:
[The authors] make a valiant stab at accounting for the components [of the antibody diversity generation system], but in the end, it is a hop in the box with Calvin and Hobbes. The authors speculate that a gene from a bacterium might have luckily been transferred to an animal. Luckily, the protein coded by the gene could itself rearrange genes; and luckily, in the animal’s DNA there were signals that were near antibody genes; and so on. In the final analysis the authors identify key problems with gradualistic evolution of the immune system, but their proffered solutions are really just a disguised shrug of their shoulders (137).
Seriously, a hop in the box with Calvin and Hobbes? If you search Pubmed for RAG transposon, you’ll get 18 hits, and they’re all relevant to the evolution of the immune system. More papers deal directly with the data for the transposon hypothesis than for the much broader topic of irreducible complexity! The top two hits are recent reviews, each of which cites dozens of papers. And the first paper ever to propose the transposon hypothesis (Sakano et al. Nature 1979, which doesn’t even appear in this narrow search) has been cited hundreds of times in peer-reviewed publications.
Questions certainly remain about the details of the transposon model, but Behe makes it sound like a pie in the sky idea with no supporting data. He writes, “We can look high or we can look low, in books or in journals, but the result is the same. The scientific literature has no answers to the question of the origin of the immune system” (138). This is patently false. Behe may not like the answers, but he misleads the public when he suggests they don’t exist.
Nearly 15 years have passed since Darwin’s Black Box first came out. During that time, scientists have collected some of the most compelling evidence for the transposon hypothesis (see Part 2). What has Behe said about this new data?
In 2005, he testified in a now-famous Dover, Pennsylvania, courtroom in favor of teaching ID alongside evolution in public schools. Behe maintained his previous position: “The scientific literature has no detailed testable answers on how the immune system could have arisen by random mutation and natural selection.”
The judge, John E. Jones, wrote in his decision that Behe “was presented with 58 peer-reviewed publications, nine books, and several immunology textbook chapters about the evolution of the immune system; however, he simply insisted that this was still not sufficient evidence of evolution…” Jones ultimately ruled against teaching ID in classrooms, in part because of the impossibly high burden of proof Behe demanded. In 2006, the 10th anniversary edition of Darwin’s Black Box appeared, featuring a new afterword. While Behe cleared up a few apparent misconceptions about irreducible complexity, he stood by the original text as a whole:
Despite the enormous progress of biochemistry in the intervening years, despite hundreds of probing commentaries…,despite implacable opposition from some scientists at the highest levels, the book’s argument for design stands. Other than updating the list of my children in the Acknowledgements…there is very little of the original text I would change if I wrote it today (255).
Specifically about the immune system, Behe mentioned one new paper from 2005, but only to reemphasize that nothing in his thinking had changed:
Whatever interesting things [the 2005 paper] speculated about gradual evolution, however, it had nothing to say about Darwinian evolution. In fact neither Darwin’s name nor any derivative word appeared in the paper. Nor did the phrase “natural selection” appear; “selection” is used once.” “Mutation” appears twice, but the envisioned mutations are not specified (269).
This sort of defense is peculiar. Behe counts words when he should be grappling with the data. Interestingly, he implicitly admits that a gradual evolutionary process may be sufficient to explain the origin of the irreducibly complex immune system, but he contrasts such a process with Darwinian evolution, by which he means mutation and natural selection.
Recall the quote I referenced in my last post, in which Behe lays out the criteria for detecting design:
The laws of nature can organize matter…The most relevant laws are those of biological reproduction, mutation, and natural selection. If a biological structure can be explained in terms of those natural laws, then we cannot conclude that it was designed. Throughout this book, however, I have shown why many biochemical systems cannot be built up by natural selection working on mutations: no direct, gradual route exists to these irreducibly complex systems… (203).
The transposon hypothesis outlines a possible gradual route to an irreducibly complex system, and it relies entirely on the laws of reproduction, mutation, and natural selection. Nevertheless, Behe remains unconvinced. In his mind, to explain the origin of an irreducibly complex system entirely in terms of natural laws, one would have to show that the steps were in fact unguided.
Such a requirement can be seen more clearly in his 2009 letter to the editor at Science, written in response to a news focus article about the origins of the immune system. Science chose not to publish the letter, so Behe posted it on the ID blog Uncommon Descent. He wrote:
Darwin’s chief contribution was not the simple idea of common descent, but the hypothesis that evolution is driven completely by ateleological mechanisms, prominently including random variation and natural selection. Intelligent design has no proper argument with the bare idea of common descent; rather, it disputes the sufficiency of ateleological mechanisms to explain all facets of biology…
Many scientists agree with Behe that evolution may have been guided in some mysterious way by a Mind. But whether or not the methods of science could ever rigorously detect teleology—mindful purpose—by studying the physical world is hotly debated. Most working scientists I know do not believe science is equipped for such a task.
Questions about teleology are fascinating, but today I’m concerned with just one thing: whether or not Behe has sufficiently engaged with the scientific literature. If I had read his book without any prior knowledge of immunology (or the other topics he covers), I’m pretty sure I would be left with a deep distrust of scientists and the scientific process. I think that’s a pity.
Kathryn Applegate is Program Director at The BioLogos Foundation. She received her PhD in computational cell biology at The Scripps Research Institute in La Jolla, Calif. At Scripps, she developed computer vision software tools for analyzing the cell's infrastructure, the cytoskeleton.