Are the sources of genetic variation uniformly random or not? That is
the central issue, and the point of entry for defenders of ID. In his recent
book, The Edge of Evolution, Michael Behe examines a body of currently
available evidence about the normal frequency and biochemical charac-
ter of random mutations in the genetic material of several organisms: the
malaria parasite, the human immunodeficiency virus (HIV), the bacte-
rium E. coli, and humans. He argues that those widely cited examples
of evolutionary adaptation, including the development of immunity
to antibiotics, when properly understood, cannot be extrapolated to
explain the formation of complex new biological systems. These, he
claims, would require mutations of a completely different order, muta-
tions whose random probability, either as simultaneous multiple muta-
tions or as sequences of separately adaptive individual mutations, is
vanishingly small. He concludes that
alterations to DNA over the course of the history of life on earth
must have included many changes that we have no statistical right
to expect, ones that were beneficial beyond the wildest reach
of probability.5
Like Kauffman, he believes that random mutation is not sufficient to
explain the range of variation on which natural selection must have
acted to yield the history of life: some of the variation was not due to
chance. This seems on the face of it to be a scientific claim, about what
the evidence suggests, and one that is not self-evidently absurd. I cannot
evaluate it; I merely want to stress its importance for the current debate.
Skepticism about the standard evolutionary model is not limited to
defenders of ID. The skeptics may be right or they may be wrong. But
even if one merely regards the randomness of the sources of variation as
an open question, it seems to call for the consideration of alternatives.
http://philosophy.fas.nyu.edu/docs/IO/1172/papa_132.pdf