Science - On the Origin of The Immune System

사이언스 2009년 5월1일자에 면역계의 기원에 관한 기사가 실렸다. 사이언스지는 지적설계 이론을 폄하하는데 오랜 역사를 가지고 있고, 그러한 전통(?)을 여전히 계승하고 있음을 보여준다. 도버 재판에서 있었던 공방에 대해서도 사실관계를 왜곡하는데, 이는 짚고 넘어가야할 것 같다.

사이언스지에서 Michael Behe의 면역계의 진화와 관련된 증언에 대해 이렇게 기술하고 있다.

When Behe reiterated that belief, Rothschild was ready. He began piling in front of the witness a large stack of recent journal articles, books, and book chapters, all relating research on the evolutionary origins of immunity, and asking Behe several times what he thought about the various publications. The biochemist admitted that he hadn't read much of the material, but he wouldn't budge from his position.

"So these are not good enough?" Rothschild asked at one point.

"They're wonderful articles. ... They simply just don't address the question that I pose," Behe responded.

The judge, John E. Jones, found Behe's responses revealing. 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," the judge wrote in his decision. Jones concluded that ID proponents set "a scientifically unreasonable burden of proof for the theory of evolution." Score one for evolution, which is now taught without competition from ID in Dover schools.

법정에 제출된 면역계 진화에 관한 자료들

 

마치, 수많은 면역계의 진화에 관련된 자료를 제시했음에도 Dr. Behe가 제대로 읽어오지 않았고, 오히려 이정도로는 충분치 않다고 했다는 식의 설명은 사실관계를 왜곡하는 것이다. 이러한 왜곡은 심판대의 지적설계(Judgment Day)라는 다큐멘터리에서도 똑같이 방영된 바 있어서 놀랄만한 일은 아니다. 이에 대해서는 이전 포스트를 참조하기 바란다.

Dr. Behe는 공통조상을 의심없이 받아들이는 지적설계 지지자이다. 그를 포함한 대다수의 지적설계 지지자들의 제기하는 질문은 과연 무작위적 변이와 자연선택이라는 메커니즘이 현존하는 생명계가 공통조상에서 기원했음을 보여주는 메커니즘으로 충분한가라는 질문을 제기하는 것이다. 아마도 이 기사를 쓴 사람은 Dr. Behe가 제기하는 질문이 무엇인지 조차 모르고 있음이 분명하다. Dr. Behe는 그 모든 자료들이 자기가 제기하는 질문에 충분한 답을 제시하는 것이 없다고 이야기하는 것이다.

 그들의 주된 rhetoric은 common descent 즉 공통조상의 근거로 사용되는 species간에 공유되는 homology에 대한 것을 보여주며 이것이 곧 진화의 증거라는 것이다. 공통조상이 진화의 핵심이라는 주장은 다윈과 라마르크의 주장의 차이를 이해하지 못하는 것과 다를 바 없다. 다윈의 핵심적인 기여는 공통조상에 관한 것이 아니다. 그의 주 업적은 진화의 메커니즘으로 무작위적 변이(random variations)와 자연선택(natural selection)을 제시했기 때문이며, 그것을 다윈주의식 메커니즘(Darwinian mechanism)이라 부르는 이유이기도 하다. 지적설계에서 의문을 제기하는 것은 바로 Darwinian mechanism이 충분한가라는 데에 있다.

Dr. Behe는 그의 블로그를 통해 자신이 Science지의 편집자에게 보낸 편지를 공개했다. 물론 사이언스지는 이를 게재하는 것을 거절했지만 말이다.
아래는 Behe의 편지 전문이다.

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