A monthly e-column by Massimo Pigliucci
face it: creationists don’t have an easy time claiming academic superiority
over their opponents. As much as they call themselves “scientific”
creationists (essentially an oxymoron), and despite the existence of the
Institute for Creation Research (whatever that is), and even of creationist
museums, anybody can see that the credentials of most creationists are as good
as those of a car salesman. Yet, there is a group of creationists (who don’t
actually like being labeled as such) that is trying—with some success—to
make headway in the academic world, or at least with the media and some
relatively high ranking politicians. Meet the Intelligent Design (ID) movement,
perhaps the most sophisticated attack on modern science mounted so far.
you, gaining a sympathetic ear within academia does not necessarily imply
intellectual respectability. Post-modernist philosophers and social scientists
have been littering college classrooms and wasting a lot of perfectly good trees
to spread nonsense about the alleged equal access to truth of any “cultural
construction,” putting science and astrology (or, for that matter,
creationism) on equal footing. But some ID exponents have legitimate PhDs in
science disciplines, they don’t make wild claims about a young earth or a
six-day creation, and even manage to get published by major academic presses.
So, who are these neo-creationists, and is there anything of substance to their
claims about evidence for an intelligent creator of the universe?
the first and most important salvo of the modern ID movement was Michael
Behe’s book, Darwin’s Black Box: the Biochemical Challenge to Evolution
(1996). Behe is a biochemist at Lehigh University in Pennsylvania and clearly
says that he accepts a lot of evolution, so much so that he should get in plenty
of trouble with “old-time religion” creationists. However, Behe draws the
line at the molecular level: while evolutionists might be able to explain how
humans descended from other primates, and might even have a good explanation for
the evolution of the eye, they can’t tell us how complex biochemical pathways
came into existence. Take blood clotting, for example. In order for the blood to
coagulate when a cut through the skin is made, several proteins have to act in a
precise sequence. Take any of them out, and you bleed to death. Or consider the
flagellum of a bacterium (the “tail” that allows some bacteria to swim). It
is made of several parts intricately interconnected to each other. Again, take
one of them away, and the bacterial cell will be stuck in place forever. But,
notices Behe, evolution is supposed to work gradually and to assemble structures
that work at every single step (since it cannot predict the future use of
something). This creates an apparent paradox whence a mindless natural force is
supposed to come up with something that smells terribly of intelligent design.
Isn’t this a deathblow to evolution as the explanation of life’s
so fast. There are a few things missing from Behe’s scenario which are worth
considering briefly. First, he has not done his homework. Contrary to what he
repeatedly claims in his book, biologists have done a bit of research on the
evolution of biochemical pathways, and there are several known examples of
bacterial flagella that are simpler than the one Behe conveniently uses. It
doesn’t take a rocket scientist (or a biochemist) to figure out that in fact
these simpler versions could easily represent intermediate steps toward complex
flagella. Second, it is not true—again contra Behe—that biochemical pathways
are assembled in a way that one cannot take any element away without having the
whole system collapsing. In fact, most of genetical research is based on the
ability to produce mutations that knock down certain genes (and therefore
certain components of biochemical pathways) while still yielding a functional
organism to be studied. One of the major discoveries of 20th century
molecular biology (which Behe must have somehow missed) is that organisms are
not irreducibly complex at all; rather, they show redundant complexity:
they are made of several parts that have no unique and irreplaceable function.
As biologist Francois Jacob put it, this is exactly what you would expect if
natural selection worked like a bricoleur rather than a cunning engineer. A
bricoleur is somebody who assembles new things out of old parts that are easily
available. The result is bound to be complex, redundant, suboptimal, and not too
pretty. Exactly like living organisms, and precisely what you would expect from
a natural phenomenon. No intelligent design required.
makes at least two fundamental mistakes in his attack against evolutionary
biology (other than neglecting to check the available literature more
thoroughly). Perhaps the subtler of the two is that he completely ignores the
fact that evolutionary biology deals with historical as well as current events.
If one picks a modern organism, say a bacterium of the species Escherichia
coli, and tries to imagine how it could have evolved, one is up against a
huge problem: what you see today under the microscope is not a “primitive”
organism, but the result of (literally) billions of years of change. As we know
from organisms that actually leave fossils (contrary to most bacteria), more
than 99% of the species that ever existed went extinct. Since most of these
don’t leave fossils (especially bacteria), we are lucky if we see a few
intermediate links at all, alive or in the fossil record. No wonder that
evolution may look like a series of huge jumps that could not possibly have been
the result of natural selection. Yet Behe behaves as if we didn’t know
anything about extinction and evolution, and bases his argument on an extremely
naive picture of biological research and of science in general.
second fatal mistake is common to all versions of Intelligent Design: the whole
approach is essentially based on an argument from ignorance. Let us assume that
biologists really don’t have the foggiest about the way a particular
biochemical pathway (aerobic respiration in mitochondria, for example) came
about. What is that supposed to prove? If Behe were alive at the time of
Aristotle, would he be arguing that lightning is clear proof of Zeus’
existence because we have no idea of how a natural phenomenon could possibly
provoke such a sudden discharge of energy? And yet this is exactly what the core
of Behe’s argument is: since we don’t know how it happened, it must have
been God. Sorry, Michael, but science is about working hard to find the answers.
Bailing out while invoking a Deus-ex-machina is not the name of the game.
Next Month: "Split-brains,
Miller’s web site at Brown University: how to debunk Behe in a few strokes
of the keyboard.
Behe’s own web site.
more debunking of Behe, visit Niall
Shank’s web site at East Tennessee State University.
Skeptic & Humanist Web