Edge: ONE SIDE CAN BE WRONG by Richard Dawkins & Jerry Coyne

The seductive "let's teach the controversy" language still

false, and highly pernicious, idea that there really are two

This
would distract students from the genuinely important and

controversies that enliven evolutionary discourse. Worse, it

hand
creationism the only victory it realistically aspires to.

needing
to make a single good point in any argument, it would have won

right
for a form of supernaturalism to be recognised as an authentic

science. And that would be the end of science education in

ONE SIDE CAN BE WRONG [9.1.05]
by Richard Dawkins & Jerry Coyne

RICHARD DAWKINS is Charles Simonyi professor of the public
understanding
of science at Oxford University. His latest book is The

Tale: A
Pilgrimage to the Dawn of Life.

JERRY COYNE is a professor in the department of ecology and

at
the University of Chicago, and the author (with H. Allen Orr)

Speciation.

ONE SIDE CAN BE WRONG
(RICHARD DAWKINS & JERRY COYNE:) It sounds so reasonable,

Such
a modest proposal. Why not teach "both sides" and let the

decide
for themselves? As President Bush said, "You're asking me

not
people ought to be exposed to different ideas, the answer is

first hearing, everything about the phrase "both sides" warms

hearts
of educators like ourselves.
One of us spent years as an Oxford tutor and it was his habit

choose
controversial topics for the students' weekly essays. They

required
to go to the library, read about both sides of an argument,

fair
account of both, and then come to a balanced judgment in their

The
call for balance, by the way, was always tempered by the

two
opposite points of view are expressed with equal intensity,

does
not necessarily lie exactly half way between. It is possible

side
simply to be wrong."
As teachers, both of us have found that asking our students to

controversies is of enormous value to their education. What is

then, with teaching both sides of the alleged controversy

evolution and creationism or "intelligent design" (ID)? And,

way,
don't be fooled by the disingenuous euphemism. There is

about
ID. It is simply creationism camouflaged with a new name to

some success, thanks to loads of tax-free money and slick
public-relations
professionals) under the radar of the US Constitution's

separation between church and state.
Why, then, would two lifelong educators and passionate

the
"both sides" style of teaching join with essentially all

making an exception of the alleged controversy between

evolution? What is wrong with the apparently sweet

"it
is only fair to teach both sides"? The answer is simple. This

scientific controversy at all. And it is a time-wasting

because evolutionary science, perhaps more than any other

science,
is bountifully endowed with genuine controversy.
Among the controversies that students of evolution commonly

these
are genuinely challenging and of great educational value:

versus selectionism in molecular evolution; adaptationism;

selection; punctuated equilibrium; cladism; "evo-devo"; the

Explosion"; mass extinctions; interspecies competition;

speciation; sexual selection; the evolution of sex itself;
evolutionary
psychology; Darwinian medicine and so on. The point is that

controversies, and many more, provide fodder for fascinating

lively
argument, not just in essays but for student discussions late

night.
Intelligent design is not an argument of the same character as

controversies. It is not a scientific argument at all, but a

one. It might be worth discussing in a class on the history of

in a
philosophy class on popular logical fallacies, or in a

religion class on origin myths from around the world. But it

belongs in a biology class than alchemy belongs in a chemistry

phlogiston in a physics class or the stork theory in a sex

class. In those cases, the demand for equal time for "both

would
be ludicrous. Similarly, in a class on 20th-century European

who
would demand equal time for the theory that the Holocaust

happened?
So, why are we so sure that intelligent design is not a real
scientific
theory, worthy of "both sides" treatment? Isn't that just our

opinion? It is an opinion shared by the vast majority of

biologists, but of course science does not proceed by majority

among
scientists. Why isn't creationism (or its incarnation as

design) just another scientific controversy, as worthy of

debate as the dozen essay topics we listed above? Here's why.
If ID really were a scientific theory, positive evidence for

gathered
through research, would fill peer-reviewed scientific

doesn't happen. It isn't that editors refuse to publish ID

There
simply isn't any ID research to publish. Its advocates bypass

scientific due process by appealing directly to the

public
and - with great shrewdness - to the government officials they

The argument the ID advocates put, such as it is, is always of

same
character. Never do they offer positive evidence in favour of
intelligent
design. All we ever get is a list of alleged deficiencies in
evolution. We
are told of "gaps" in the fossil record. Or organs are stated,

and
without supporting evidence, to be "irreducibly complex": too

to
have evolved by natural selection.
In all cases there is a hidden (actually they scarcely even

hide
it) "default" assumption that if Theory A has some difficulty

explaining Phenomenon X, we must automatically prefer Theory B

even asking whether Theory B (creationism in this case) is any

at
explaining it. Note how unbalanced this is, and how it gives

to
the apparent reasonableness of "let's teach both sides". One

required to produce evidence, every step of the way. The other

never required to produce one iota of evidence, but is deemed

won
automatically, the moment the first side encounters a

sort of difficulty that all sciences encounter every day, and

work
to solve, with relish.
What, after all, is a gap in the fossil record? It is simply

absence
of a fossil which would otherwise have documented a particular
evolutionary transition. The gap means that we lack a complete
cinematic
record of every step in the evolutionary process. But how

presumptuous to demand a complete record, given that only a

proportion of deaths result in a fossil anyway.
The equivalent evidential demand of creationism would be a

cinematic record of God's behaviour on the day that he went to

on,
say, the mammalian ear bones or the bacterial flagellum - the

hair-like organ that propels mobile bacteria. Not even the

advocate of intelligent design claims that any such divine

will
ever become available.
Biologists, on the other hand, can confidently claim the

"cinematic" sequence of fossils for a very large number of
evolutionary
transitions. Not all, but very many, including our own descent

the
bipedal ape Australopithecus. And - far more telling - not a

authentic fossil has ever been found in the "wrong" place in

evolutionary sequence. Such an anachronistic fossil, if one

unearthed, would blow evolution out of the water.
As the great biologist J B S Haldane growled, when asked what

disprove evolution: "Fossil rabbits in the pre-Cambrian."

like
all good theories, makes itself vulnerable to disproof.

say,
it has always come through with flying colours.
Similarly, the claim that something - say the bacterial

too
complex to have evolved by natural selection is alleged, by a
lamentably
common but false syllogism, to support the "rival" intelligent

theory by default. This kind of default reasoning leaves

open
the possibility that, if the bacterial flagellum is too

have
evolved, it might also be too complex to have been created.

indeed, a
moment's thought shows that any God capable of creating a

flagellum (to say nothing of a universe) would have to be a

complex, and therefore statistically improbable, entity than

bacterial
flagellum (or universe) itself - even more in need of an

than
the object he is alleged to have created.
If complex organisms demand an explanation, so does a complex
designer.
And it's no solution to raise the theologian's plea that God

Intelligent Designer) is simply immune to the normal demands

scientific
explanation. To do so would be to shoot yourself in the foot.

cannot
have it both ways. Either ID belongs in the science classroom,

which
case it must submit to the discipline required of a scientific
hypothesis.
Or it does not, in which case get it out of the science

send
it back into the church, where it belongs.
In fact, the bacterial flagellum is certainly not too complex

evolved, nor is any other living structure that has ever been
carefully
studied. Biologists have located plausible series of

using
ingredients to be found elsewhere in living systems. But even

particular case were found for which biologists could offer no

explanation, the important point is that the "default" logic

creationists remains thoroughly rotten.
There is no evidence in favour of intelligent design: only

gaps in
the completeness of the evolutionary account, coupled with the
"default"
fallacy we have identified. And, while it is inevitably true

there
are incompletenesses in evolutionary science, the positive

for
the fact of evolution is truly massive, made up of hundreds of
thousands
of mutually corroborating observations. These come from areas

geology, paleontology, comparative anatomy, physiology,

ethology, biogeography, embryology and - increasingly

molecular
genetics.
The weight of the evidence has become so heavy that opposition

fact
of evolution is laughable to all who are acquainted with even

fraction
of the published data. Evolution is a fact: as much a fact as

tectonics or the heliocentric solar system.
Why, finally, does it matter whether these issues are

science
classes? There is a case for saying that it doesn't - that

shouldn't get so hot under the collar. Perhaps we should just

the
popular demand that we teach ID as well as evolution in

classes.
It would, after all, take only about 10 minutes to exhaust the

for
ID, then we could get back to teaching real science and

controversy.
Tempting as this is, a serious worry remains. The seductive

teach
the controversy" language still conveys the false, and highly
pernicious,
idea that there really are two sides. This would distract

from
the genuinely important and interesting controversies that

evolutionary discourse. Worse, it would hand creationism the

victory
it realistically aspires to. Without needing to make a single

point
in any argument, it would have won the right for a form of
supernaturalism
to be recognised as an authentic part of science. And that

the
end of science education in America.
Arguments worth having ...
The "Cambrian Explosion"
Although the fossil record shows that the first multicellular

lived about 640m years ago, the diversity of species was low

about
530m years ago. At that time there was a sudden explosion of

diverse
marine species, including the first appearance of molluscs,
arthropods,
echinoderms and vertebrates. "Sudden" here is used in the

sense; the "explosion" occurred over a period of 10m to 30m

which
is, after all, comparable to the time taken to evolve most of

great
radiations of mammals. This rapid diversification raises

questions; explanations include the evolution of organisms

parts
(which aid fossilisation), the evolutionary "discovery" of

the
development of new genes that allowed parts of organisms to

independently.
The evolutionary basis of human behaviour
The field of evolutionary psychology (once called

maintains that many universal traits of human behaviour

sexual
behaviour), as well as differences between individuals and

ethnic
groups, have a genetic basis. These traits and differences are

have evolved in our ancestors via natural selection. There is

controversy about these claims, largely because it is hard to
reconstruct
the evolutionary forces that acted on our ancestors, and it is
unethical
to do genetic experiments on modern humans.
Sexual versus natural selection
Although evolutionists agree that adaptations invariably

natural selection, there are many traits, such as the

plumage of
male birds and size differences between the sexes in many

that
are better explained by "sexual selection": selection based on

of
one sex (usually females) preferring to mate with members of

sex
that show certain desirable traits. Evolutionists debate how

features
of animals have resulted from sexual as opposed to natural

some, like Darwin himself, feel that many physical features
differentiating human "races" resulted from sexual selection.
The target of natural selection
Evolutionists agree that natural selection usually acts on

organisms - individuals carrying genes that give them a

or
survival advantage over others will leave more descendants,

changing the genetic composition of a species. This is called
"individual
selection". But some evolutionists have proposed that

act at
higher levels as well: on populations (group selection), or

species themselves (species selection). The relative

individual versus these higher order forms of selection is a

lively debate.
Natural selection versus genetic drift
Natural selection is a process that leads to the replacement

gene
by another in a predictable way. But there is also a "random"

nary
process called genetic drift, which is the genetic equivalent

coin-tossing. Genetic drift leads to unpredictable changes in

frequencies of genes that don't make much difference to the

of
their carriers, and can cause evolution by changing the

composition of populations. Many features of DNA are said to

evolved
by genetic drift. Evolutionary geneticists disagree about the
importance
of selection versus drift in explaining features of organisms

their
DNA. All evolutionists agree that genetic drift can't explain

evolution. But not all evolution is adaptive.