July 1, 2007
Inferior Design
By RICHARD DAWKINS
http://preview.tinyurl.com/29yto9
Reviews:
"THE EDGE OF EVOLUTION "
The Search for the Limits of Darwinism.
By Michael J. Behe.
320 pp. Free Press. $28. (Free?!)
"I had expected to be as irritated by Michael Behe's second book as by
his first. I had not expected to feel sorry for him. The first —
"Darwin's Black Box" (1996), which purported to make the scientific
case for "intelligent design" — was enlivened by a spark of
conviction, however misguided. The second is the book of a man who has
given up. Trapped along a false path of his own rather unintelligent
design, Behe has left himself no escape. Poster boy of creationists
everywhere, he has cut himself adrift from the world of real science.
And real science, in the shape of his own department of biological
sciences at Lehigh University, has publicly disowned him, via a
remarkable disclaimer on its Web site: "While we respect Prof. Behe's
right to express his views, they are his alone and are in no way
endorsed by the department. It is our collective position that
intelligent design has no basis in science, has not been tested
experimentally and should not be regarded as scientific." As the
Chicago geneticist Jerry Coyne wrote recently, in a devastating review
of Behe's work in The New Republic, it would be hard to find a
precedent.
For a while, Behe built a nice little career on being a maverick. His
colleagues might have disowned him, but they didn't receive flattering
invitations to speak all over the country and to write for The New
York Times. Behe's name, and not theirs, crackled triumphantly around
the memosphere. But things went wrong, especially at the famous 2005
trial where Judge John E. Jones III immortally summed up as
"breathtaking inanity" the effort to introduce intelligent design into
the school curriculum in Dover, Pa. After his humiliation in court,
Behe — the star witness for the creationist side — might have wished
to re-establish his scientific credentials and start over.
Unfortunately, he had dug himself in too deep. He had to soldier on.
"The Edge of Evolution" is the messy result, and it doesn't make for
attractive reading.
We now hear less about "irreducible complexity," with good reason. In
"Darwin's Black Box," Behe simply asserted without justification that
particular biological structures (like the bacterial flagellum, the
tiny propeller by which bacteria swim) needed all their parts to be in
place before they would work, and therefore could not have evolved
incrementally. This style of argument remains as unconvincing as when
Darwin himself anticipated it. It commits the logical error of arguing
by default. Two rival theories, A and B, are set up. Theory A explains
loads of facts and is supported by mountains of evidence. Theory B has
no supporting evidence, nor is any attempt made to find any. Now a
single little fact is discovered, which A allegedly can't explain.
Without even asking whether B can explain it, the default conclusion
is fallaciously drawn: B must be correct. Incidentally, further
research usually reveals that A can explain the phenomenon after all:
thus the biologist Kenneth R. Miller (a believing Christian who
testified for the other side in the Dover trial) beautifully showed
how the bacterial flagellar motor could evolve via known functional
intermediates.
Behe correctly dissects the Darwinian theory into three parts: descent
with modification, natural selection and mutation. Descent with
modification gives him no problems, nor does natural selection. They
are "trivial" and "modest" notions, respectively. Do his creationist
fans know that Behe accepts as "trivial" the fact that we are African
apes, cousins of monkeys, descended from fish?
The crucial passage in "The Edge of Evolution" is this: "By far the
most critical aspect of Darwin's multifaceted theory is the role of
random mutation. Almost all of what is novel and important in
Darwinian thought is concentrated in this third concept."
What a bizarre thing to say! Leave aside the history: unacquainted
with genetics, Darwin set no store by randomness. New variants might
arise at random, or they might be acquired characteristics induced by
food, for all Darwin knew. Far more important for Darwin was the
nonrandom process whereby some survived but others perished. Natural
selection is arguably the most momentous idea ever to occur to a human
mind, because it — alone as far as we know — explains the elegant
illusion of design that pervades the living kingdoms and explains, in
passing, us. Whatever else it is, natural selection is not a "modest"
idea, nor is descent with modification.
But let's follow Behe down his solitary garden path and see where his
overrating of random mutation leads him. He thinks there are not
enough mutations to allow the full range of evolution we observe.
There is an "edge," beyond which God must step in to help. Selection
of random mutation may explain the malarial parasite's resistance to
chloroquine, but only because such micro-organisms have huge
populations and short life cycles. A fortiori, for Behe, evolution of
large, complex creatures with smaller populations and longer
generations will fail, starved of mutational raw materials.
If mutation, rather than selection, really limited evolutionary
change, this should be true for artificial no less than natural
selection. Domestic breeding relies upon exactly the same pool of
mutational variation as natural selection. Now, if you sought an
experimental test of Behe's theory, what would you do? You'd take a
wild species, say a wolf that hunts caribou by long pursuit, and apply
selection experimentally to see if you could breed, say, a dogged
little wolf that chivies rabbits underground: let's call it a Jack
Russell terrier. Or how about an adorable, fluffy pet wolf called, for
the sake of argument, a Pekingese? Or a heavyset, thick-coated wolf,
strong enough to carry a cask of brandy, that thrives in Alpine passes
and might be named after one of them, the St. Bernard? Behe has to
predict that you'd wait till hell freezes over, but the necessary
mutations would not be forthcoming. Your wolves would stubbornly
remain unchanged. Dogs are a mathematical impossibility.
Don't evade the point by protesting that dog breeding is a form of
intelligent design. It is (kind of), but Behe, having lost the
argument over irreducible complexity, is now in his desperation making
a completely different claim: that mutations are too rare to permit
significant evolutionary change anyway. From Newfies to Yorkies, from
Weimaraners to water spaniels, from Dalmatians to dachshunds, as I
incredulously close this book I seem to hear mocking barks and deep,
baying howls of derision from 500 breeds of dogs — every one descended
from a timber wolf within a time frame so short as to seem, by
geological standards, instantaneous.
If correct, Behe's calculations would at a stroke confound generations
of mathematical geneticists, who have repeatedly shown that
evolutionary rates are not limited by mutation. Single-handedly, Behe
is taking on Ronald Fisher, Sewall Wright, J. B. S. Haldane,
Theodosius Dobzhansky, Richard Lewontin, John Maynard Smith and
hundreds of their talented co-workers and intellectual descendants.
Notwithstanding the inconvenient existence of dogs, cabbages and
pouter pigeons, the entire corpus of mathematical genetics, from 1930
to today, is flat wrong. Michael Behe, the disowned biochemist of
Lehigh University, is the only one who has done his sums right. You
think?
The best way to find out is for Behe to submit a mathematical paper to
The Journal of Theoretical Biology, say, or The American Naturalist,
whose editors would send it to qualified referees. They might liken
Behe's error to the belief that you can't win a game of cards unless
you have a perfect hand. But, not to second-guess the referees, my
point is that Behe, as is normal at the grotesquely ill-named
Discovery Institute (a tax-free charity, would you believe?), where he
is a senior fellow, has bypassed the peer-review procedure altogether,
gone over the heads of the scientists he once aspired to number among
his peers, and appealed directly to a public that — as he and his
publisher know — is not qualified to rumble him."
Richard Dawkins holds the Charles Simonyi chair for the public
understanding of science at Oxford. His most recent book is "The God
Delusion."
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