[Chat] The Guardian: One side can be wrong
charlesvillager2002 at yahoo.com
Thu Sep 1 16:35:53 EDT 2005
One side can be wrong
Accepting 'intelligent design' in science classrooms
would have disastrous consequences, warn Richard
Dawkins and Jerry Coyne
Richard Dawkins and Jerry Coyne
Thursday September 1, 2005
It sounds so reasonable, doesn't it? Such a modest
proposal. Why not teach "both sides" and let the
children decide for themselves? As President Bush
said, "You're asking me whether or not people ought to
be exposed to different ideas, the answer is yes." At
first hearing, everything about the phrase "both
sides" warms the hearts of educators like ourselves.
One of us spent years as an Oxford tutor and it was
his habit to choose controversial topics for the
students' weekly essays. They were required to go to
the library, read about both sides of an argument,
give a fair account of both, and then come to a
balanced judgment in their essay. The call for
balance, by the way, was always tempered by the maxim,
"When two opposite points of view are expressed with
equal intensity, the truth does not necessarily lie
exactly half way between. It is possible for one side
simply to be wrong."
As teachers, both of us have found that asking our
students to analyse controversies is of enormous value
to their education. What is wrong, then, with teaching
both sides of the alleged controversy between
evolution and creationism or "intelligent design"
(ID)? And, by the way, don't be fooled by the
disingenuous euphemism. There is nothing new about ID.
It is simply creationism camouflaged with a new name
to slip (with some success, thanks to loads of
tax-free money and slick public-relations
professionals) under the radar of the US
Constitution's mandate for separation between church
Why, then, would two lifelong educators and passionate
advocates of the "both sides" style of teaching join
with essentially all biologists in making an exception
of the alleged controversy between creation and
evolution? What is wrong with the apparently sweet
reasonableness of "it is only fair to teach both
sides"? The answer is simple. This is not a scientific
controversy at all. And it is a time-wasting
distraction because evolutionary science, perhaps more
than any other major science, is bountifully endowed
with genuine controversy.
Among the controversies that students of evolution
commonly face, these are genuinely challenging and of
great educational value: neutralism versus
selectionism in molecular evolution; adaptationism;
group selection; punctuated equilibrium; cladism;
"evo-devo"; the "Cambrian Explosion"; mass
extinctions; interspecies competition; sympatric
speciation; sexual selection; the evolution of sex
itself; evolutionary psychology; Darwinian medicine
and so on. The point is that all these controversies,
and many more, provide fodder for fascinating and
lively argument, not just in essays but for student
discussions late at night.
Intelligent design is not an argument of the same
character as these controversies. It is not a
scientific argument at all, but a religious one. It
might be worth discussing in a class on the history of
ideas, in a philosophy class on popular logical
fallacies, or in a comparative religion class on
origin myths from around the world. But it no more
belongs in a biology class than alchemy belongs in a
chemistry class, phlogiston in a physics class or the
stork theory in a sex education class. In those cases,
the demand for equal time for "both theories" would be
ludicrous. Similarly, in a class on 20th-century
European history, who would demand equal time for the
theory that the Holocaust never 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 personal opinion? It is
an opinion shared by the vast majority of professional
biologists, but of course science does not proceed by
majority vote among scientists. Why isn't creationism
(or its incarnation as intelligent design) just
another scientific controversy, as worthy of
scientific debate as the dozen essay topics we listed
above? Here's why.
If ID really were a scientific theory, positive
evidence for it, gathered through research, would fill
peer-reviewed scientific journals. This doesn't
happen. It isn't that editors refuse to publish ID
research. There simply isn't any ID research to
publish. Its advocates bypass normal scientific due
process by appealing directly to the non-scientific
public and - with great shrewdness - to the government
officials they elect.
The argument the ID advocates put, such as it is, is
always of the 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, by fiat and without supporting
evidence, to be "irreducibly complex": too complex to
have evolved by natural selection.
In all cases there is a hidden (actually they scarcely
even bother to hide it) "default" assumption that if
Theory A has some difficulty in explaining Phenomenon
X, we must automatically prefer Theory B without even
asking whether Theory B (creationism in this case) is
any better at explaining it. Note how unbalanced this
is, and how it gives the lie to the apparent
reasonableness of "let's teach both sides". One side
is required to produce evidence, every step of the
way. The other side is never required to produce one
iota of evidence, but is deemed to have won
automatically, the moment the first side encounters a
difficulty - the sort of difficulty that all sciences
encounter every day, and go to work to solve, with
What, after all, is a gap in the fossil record? It is
simply the 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
incredibly presumptuous to demand a complete record,
given that only a minuscule proportion of deaths
result in a fossil anyway.
The equivalent evidential demand of creationism would
be a complete cinematic record of God's behaviour on
the day that he went to work on, say, the mammalian
ear bones or the bacterial flagellum - the small,
hair-like organ that propels mobile bacteria. Not even
the most ardent advocate of intelligent design claims
that any such divine videotape will ever become
Biologists, on the other hand, can confidently claim
the equivalent "cinematic" sequence of fossils for a
very large number of evolutionary transitions. Not
all, but very many, including our own descent from the
bipedal ape Australopithecus. And - far more telling -
not a single authentic fossil has ever been found in
the "wrong" place in the evolutionary sequence. Such
an anachronistic fossil, if one were ever unearthed,
would blow evolution out of the water.
As the great biologist J B S Haldane growled, when
asked what might disprove evolution: "Fossil rabbits
in the pre-Cambrian." Evolution, like all good
theories, makes itself vulnerable to disproof.
Needless to say, it has always come through with
Similarly, the claim that something - say the
bacterial flagellum - is too complex to have evolved
by natural selection is alleged, by a lamentably
common but false syllogism, to support the "rival"
intelligent design theory by default. This kind of
default reasoning leaves completely open the
possibility that, if the bacterial flagellum is too
complex to have evolved, it might also be too complex
to have been created. And indeed, a moment's thought
shows that any God capable of creating a bacterial
flagellum (to say nothing of a universe) would have to
be a far more complex, and therefore statistically
improbable, entity than the bacterial flagellum (or
universe) itself - even more in need of an explanation
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 (or the Intelligent
Designer) is simply immune to the normal demands of
scientific explanation. To do so would be to shoot
yourself in the foot. You cannot have it both ways.
Either ID belongs in the science classroom, in 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 classroom and send it back
into the church, where it belongs.
In fact, the bacterial flagellum is certainly not too
complex to have evolved, nor is any other living
structure that has ever been carefully studied.
Biologists have located plausible series of
intermediates, using ingredients to be found elsewhere
in living systems. But even if some particular case
were found for which biologists could offer no ready
explanation, the important point is that the "default"
logic of the creationists remains thoroughly rotten.
There is no evidence in favour of intelligent design:
only alleged gaps in the completeness of the
evolutionary account, coupled with the "default"
fallacy we have identified. And, while it is
inevitably true that there are incompletenesses in
evolutionary science, the positive evidence for the
fact of evolution is truly massive, made up of
hundreds of thousands of mutually corroborating
observations. These come from areas such as geology,
paleontology, comparative anatomy, physiology,
biochemistry, ethology, biogeography, embryology and -
increasingly nowadays - molecular genetics.
The weight of the evidence has become so heavy that
opposition to the fact of evolution is laughable to
all who are acquainted with even a fraction of the
published data. Evolution is a fact: as much a fact as
plate tectonics or the heliocentric solar system.
Why, finally, does it matter whether these issues are
discussed in science classes? There is a case for
saying that it doesn't - that biologists shouldn't get
so hot under the collar. Perhaps we should just accept
the popular demand that we teach ID as well as
evolution in science classes. It would, after all,
take only about 10 minutes to exhaust the case for ID,
then we could get back to teaching real science and
Tempting as this is, a serious worry remains. The
seductive "let's teach the controversy" language still
conveys the false, and highly pernicious, idea that
there really are two sides. This would distract
students from the genuinely important and interesting
controversies that enliven evolutionary discourse.
Worse, it would hand creationism the only victory it
realistically aspires to. Without needing to make a
single good 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
would be the end of science education in America.
Arguments worth having ...
The "Cambrian Explosion"
Although the fossil record shows that the first
multicellular animals lived about 640m years ago, the
diversity of species was low until about 530m years
ago. At that time there was a sudden explosion of many
diverse marine species, including the first appearance
of molluscs, arthropods, echinoderms and vertebrates.
"Sudden" here is used in the geological sense; the
"explosion" occurred over a period of 10m to 30m
years, which is, after all, comparable to the time
taken to evolve most of the great radiations of
mammals. This rapid diversification raises fascinating
questions; explanations include the evolution of
organisms with hard parts (which aid fossilisation),
the evolutionary "discovery" of eyes, and the
development of new genes that allowed parts of
organisms to evolve independently.
The evolutionary basis of human behaviour
The field of evolutionary psychology (once called
"sociobiology") maintains that many universal traits
of human behaviour (especially sexual behaviour), as
well as differences between individuals and between
ethnic groups, have a genetic basis. These traits and
differences are said to have evolved in our ancestors
via natural selection. There is much 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 result from natural selection, there are
many traits, such as the elaborate plumage of male
birds and size differences between the sexes in many
species, that are better explained by "sexual
selection": selection based on members of one sex
(usually females) preferring to mate with members of
the other sex that show certain desirable traits.
Evolutionists debate how many features of animals have
resulted from sexual as opposed to natural selection;
some, like Darwin himself, feel that many physical
features differentiating human "races" resulted from
The target of natural selection
Evolutionists agree that natural selection usually
acts on genes in organisms - individuals carrying
genes that give them a reproductive or survival
advantage over others will leave more descendants,
gradually changing the genetic composition of a
species. This is called "individual selection". But
some evolutionists have proposed that selection can
act at higher levels as well: on populations (group
selection), or even on species themselves (species
selection). The relative importance of individual
versus these higher order forms of selection is a
topic of lively debate.
Natural selection versus genetic drift
Natural selection is a process that leads to the
replacement of one gene by another in a predictable
way. But there is also a "random" evolutionary process
called genetic drift, which is the genetic equivalent
of coin-tossing. Genetic drift leads to unpredictable
changes in the frequencies of genes that don't make
much difference to the adaptation of their carriers,
and can cause evolution by changing the genetic
composition of populations. Many features of DNA are
said to have evolved by genetic drift. Evolutionary
geneticists disagree about the importance of selection
versus drift in explaining features of organisms and
their DNA. All evolutionists agree that genetic drift
can't explain adaptive evolution. But not all
evolution is adaptive.
Website explaining evolution in user-friendly fashion
Climbing Mount Improbable
Richard Dawkin (illustrations by Lalla Ward), Penguin
Evolution versus Creationism
Eugenie C Scott, Greenwood Press, 2004
· Richard Dawkins is Charles Simonyi professor of the
public understanding of science at Oxford University,
and Jerry Coyne is a professor in the department of
ecology and evolution at the University of Chicago
Richard Dawkins book 'The Ancestor's Tale: A
Pilgrimage to the Dawn of Life' is published by
Phoenix in paperback.
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