The May 1st issue of Science
contains a “News Focus” article entitled “On the Origin of the Immune System
.” While describing some current work in the area the author, John Travis, makes liberal use of myself as an unreasonably-skeptical foil. I wrote a letter to the editor of Science
pointing out inaccuracies in the story but, gee whiz, they didn’t think the letter would be of sufficient interest to their readers to print it. Below I reproduce the unpublished letter for those who might be interested in my reaction to the article.
To the editor:
In his article “On the Origin of the Immune System” (Science, May 1, 2009) John Travis makes the same mistake as did the judge in the 2005 Dover trial — badly confusing the notions of intelligent design, common descent, and evolution. Citing the courtroom theatrics of the lawyers who piled a stack of textbooks and articles in front of me, Travis quotes me as remarking “They’re wonderful articles. … They simply just don’t address the question I pose.” Unfortunately, Travis seems uninterested in what that question might be. Instead he cheers, “Score one for evolution.”
Although some news reporters, lawyers, and parents are confused on the topic, “intelligent design” is not the opposite of “evolution.” As some biologists before Darwin theorized, organisms might have descended with modification and be related by common descent, but the process might have been guided by some form of intelligence or teleological driving force in nature. 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. Those who fail to grasp such distinctions are like people who can’t distinguish between the ideas of Darwin and, say, Lamarck.
In the courtroom scenario Travis recounts, I was testifying that science has not shown that a Darwinian mechanism could account for the immune system. Travis’s article itself confirms that is still true. He cites some biologists who think the adaptive immune system arose in a “big bang”; he quotes other scientists who assert, “There was never a big bang of immunology.” He discusses vertebrate immunologists who think they know what the selective advantage of the system is; he quotes invertebrate immunologists who feel otherwise. So are we to think that its history is uncertain and even its selective advantage is unknown, yet the mechanism by which the adaptive immune system arose is settled?
In my court testimony I cited the then-new article by Klein and Nikolaidis, “The descent of the antibody-based immune system by gradual evolution
” (Proc. Natl. Acad. Sci. USA 102
:169-174, 2005), which first disputed the big bang hypothesis. In it the authors candidly remark, “Here, we sketch out some of the changes that the emergence of the AIS entailed and speculate how they may have come about.” Valuable as it might be to science, however, speculation is not data, let alone an experimental result. Students are poorly served when they are not taught to distinguish among them.
Michael J. Behe