Darwin’s Black Box: The Biochemical Challenge to Evolution by Michael J. Behe (review)

BOOK REVIEWS 493 Libraries at research universities and liberal arts colleges, particularly Catholic ones, should obtain these books for reference purposes. And graduate students, particularly theology students in Catholic universities, would do well to purchase them for their personal libraries, both for reference .and for intellectual exercise. Marquette University Milwaukee, Wisconsin MARKJOHNSON Darwin's Black Box: The Biochemical Challenge to Evolution. By MICHAEL). BEHE. New York: The Free Press, 1996. Pp. 307. $25.00 (cloth). ISBN 0-684-82754-9. Michael Behe has a gift for explaining things, be they complex biochemical processes or key philosophical terms. His clarity along with his scientific competence account for why he succeeded in capturing the attention of major scientific journals such as Nature and the American Scientist despite his opposition to neo-Darwinian orthodoxy. Behe presents a biochemical remake of Paley's argument from design. He maintains that the present inability of neo-Darwinism to explain the origin of complex biochemical systems is due to the very nature of these systems. The failure of neo-Darwinism coupled with the irreducibly complex nature of these systems leads Behe to conclude that the only adequate explanation for them is an intelligent designer. Behe begins by explaining why Paley's argument needs to be reformulated, that is, why the proper way to determine the adequacy of the neo-Darwinian explanation of evolution is by examining things at a biochemical level. Contrary to Paley, who thought that there was a need to invoke design at the level of gross anatomy to explain organs of extreme perfection, Behe maintains that at that level neo-Darwinism offers a plausible step-by-step account of the origin of such organs. The problem Behe has with neo-Darwinian explanations is that they fail to take in account the underlying biochemistry (37). He reasons that if the inner workings of something are not understood, if something is a 'black box,' there is no way one can render judgment as to whether the origin of that thing can be fully explained by random changes which accumulated gradually (8, 15). He proceeds to explain the biochemistry upon which the functioning of one complex organ depends (namely, the eye), making it amply clear that the complexity of the interactions makes it difficult to see how any adequate explanation of their origin could be be provided by Darwinian 494 BOOK REVIEWS principles. This leads him to conclude: "Now that the black box of vision has been opened, it is no longer enough for an evolutionary explanation of that power to consider only the anatomical structure of whole eyes.... Each of the anatomical steps and structures that Darwin thought were so simple actually involvesstaggeringlycomplicated biochemical processes that cannot be papered over with rhetoric" (22). Behe devotes a large part of chapter 2 (22-30) to citing respected biologists who also have difficulties with the versions of neo-Darwinism that insist on the slow accrual of mutations. He then goes on to expose what he finds problematic, by first asking: "What type of biological system could not be formed by "numerous, successive, slight modifications"?" His response is "a system that is irreducibly complex" (39). The definition of this key concept follows: "By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning" (39). He uses the simple example of a mousetrap to illustrate what he means (42, 43): for a mousetrap to function at all the hammer, string, catch, holding bar, and platform have to all be present and assembled in the appropriate way out of appropriate materials. An irreducibly complex system cannot be produced by continuously improving the initial function (which continues to work by the same mechanism), by slight, successive modifications of a precursor system, because any precursor to an irreducibly complex system that is missing a part is by definition non-functional. Behe further maintains that a system has to be working for it to be retained by natural selection, and thus that "if a biological system cannot be produced gradually it would have to arise as an integrated...