Answering the creationists: where they go
wrong - and what they're afraid of.
Ruse, Michael. Free
Inquiry03/22/98
v18:n2. p28(5)
To the working scientist, and not just the biologist, it
is simply ludicrous to think that there is any question
about the natural origin of organisms from forms very
different - ultimately, from inorganic materials. This is
as much a fact of nature as that the earth goes around
the sun or that water is made from oxygen and hydrogen.
But it is certainly not a fact to many nonscientists,
especially not to those influenced by North American
evangelical Christianity. Again and again, one hears:
"Evolution is a theory and not a fact," or some
such thing. People tend not to unpack this wise-sounding
statement, but of one thing you can be sure:
"theory" is a euphemism for "false."
Recently, the naysayers have
gained more authority as their ranks have been swelled by
people of distinction and position - not biologists
working on the problems that concern evolutionists, but
from other areas of science as well as branches of the
humanities including philosophy. I shall examine
proposals that these critics have made as an alternative
to evolution through selection, in particular, the
pretensions of the supposedly new hypothesis about
"irreducible complexity," a phenomenon that
demands the invocation of a Supreme Being of some sort.
This is a very old argument indeed. Far from being a
genuine alternative to evolutionism, it is neither needed
nor plausible. On its own terms, it is riddled with
problems.
DARWIN'S CRITICS
Creationism is the
belief that the Bible is literally true. One must
conclude that the earth and its denizens were created
miraculously some 6,000 years ago, in six days of 24-hour
duration, that humans appeared last, and that at some
later point the earth was totally submerged by water. It
is an American invention of the past century. Scorned by
mainline churches as well as by scientists, it has
nevertheless shown considerable staying power. In the
1960s, thanks to the efforts of a Bible scholar John C.
Whitcomb and hydraulic again engineer Henry M. Morris,
authors of Genesis Flood, creationism took on a whole new
life, leading eventually to court trials as certain
states of the American South tried to insist that the
children in their public schools be taught creationism as
a viable alternative alongside evolution. Beaten back in
this attempt, it seemed that perhaps creationism was at
last defeated, but phoenix-like it has arisen again, and
as the century comes to an end is perhaps showing more
life - certainly more respectability - than at any time
previously.
The new creationists are
wary of indiscriminate labeling. Most of them do admit to
religious beliefs, but they are much aware of the
ridicule that has been heaped on those who deny physics
to the extent of claiming the falsity of an earth of more
than a few thousand years of age. I suspect that most of
these people are not in fact "young earthers";
but whatever the minutiae of their beliefs, one finds
that inasmuch as these new arrivals accept the name of
"creationist," it is usually defined in such a
broad way as to be compatible with a great deal of
science, even a little bit of evolution if one is so
inclined. These new arrivals, whether from conviction or
expediency, have tended - at least, until recently - to
stay very carefully away from explications of their own
positions.
My main concern is with
the case made by Berkeley Professor of Law Phillip
Johnson, author of Darwin on Trial (1991). This has been
an immensely popular book. The most striking thing about
Johnson's work and the others following in its trail is
that its attack is curiously shallow. One would never
guess that there is at stake on the evolution side a
whole discipline, with departments and students and
journals and conferences and much much more. What one
would infer rather is that there are three or four
writers in the popular domain and these - principally
Stephen Jay Gould with one or two uncertain allies like
Richard Dawkins - are basically the beginning and end of
evolutionary biology today. So straight off, the case is
slanted against evolutionism: the level tends to that of
pop science rather than professional science. One
searches in vain in the writings of Johnson and his
fellow new creationists for any of the exciting
discoveries and theories of today that make evolution
such a vibrant area of research: the findings of
molecular evolutionists thanks to brilliant work on gel
electrophoresis by Richard Lewontin, for instance, or the
work of the sociobiologists following up the ideas of
William Hamilton or John Maynard Smith. There is nothing
on the ways in which, using modern thinking about natural
selection, students of the social insects have been able
to tease apart the relationships between workers and
queens and drones. As Thomas Kuhn and other students of
the theory. of science have rightly stressed repeatedly,
in judging a theory or paradigm or new area of science,
one must ask as much about the new directions it uncovers
as about problems one might have with foundations.
What of the science that
is actually discussed? There is a constant confusing of
the fact of evolution, and with the path or paths of
evolution, and then with the cause or mechanisms of
evolution. Making Gould today's leading evolutionist
makes the job much easier than it might otherwise be. His
theory of punctuated equilibria is paraded out; its
postulation of rapid change between periods of
nonactivity is taken as evidence of evolutionists'
problems with the paths of evolution; and then all is
wrapped up as a supposedly devastating critique of the
very fact of evolution.
We must not be bullied
by the creationists' strategy. They may ignore it but let
us continue to be guided by the threefold division of
fact, path, and cause. What has Johnson (and his fellows)
to say about the fact of evolution? The key to
understanding the evolutionist's conviction of the fact
of evolution lies in the total evidence-appealing
consilience at its heart - the very, same kind of
consilience that is at the heart of legal practice, as
prosecutors try to pin guilt on defendants through
circumstantial evidence. There is nothing on this method
of argumentation: a curious omission, especially given
that Johnson is an academic lawyer specializing in
criminal law. One consequence of this omission is that
Johnson and others can avoid talking about all of the
evidence, quite ignoring such crucial planks in the
evolutionist's case as biogeography.
Move next to questions
of path, an area that has always been a happy hunting
ground for creationists - failure to find early life
forms, the Cambrian explosion, the gaps in the fossil
record thereafter, and so forth. To quote another of the
new creationists:
Before the Cambrian era,
a brief 600 million years ago, very little is inscribed
in the fossil record; but then, signaled by what I
imagine is a spectral puff of smoke and a deafening
ta-da!, an astonishing number of novel biological
structures come into creation, and they come into
creation at once.
Thereafter, the major
transitional sequences are incomplete?
What can one say in
response, except: "Go and look at the evidence, go
and look at the explanations that evolutionists are
offering, and then if you still disagree, let us discuss
and argue. But not before. Until you do this, you have
not the authority to make such claims as this." Take
that truly remarkable explosion of life half a billion
years ago, in the Cambrian. Leading American
paleontologist John Sepkoski has put forward a theory
showing how this increase is a direct function of
population growth - it is precisely the exponential rise
one expects when a group is colonizing a new ecological
space. He argues also that this explains why the rise
comes to an end, why the early forms then declined in
numbers, why we later get another rise, and much more. He
may be right. He may be wrong. But he is worthy of
attention. Which he does not get. Tripping through Gould
and Dawkins is no substitute for real work.
Most remarkable of all
is Johnson's treatment of that old chestnut, the gaps in
the record. Expectedly, archaeopteryx - the reptile-bird
- gets short shrift. None of the intermediate features
gets an airing.
It is of course just not
true that archaeopteryx is the only bridging fossil known
to evolutionists. Take a favorite argument of the
creationists: there is a lack of transitional fossils
between the land animals and the marine animals, like
whales. Now these gaps are being filled. Proto-whales
have been discovered. We really do have fossil marine
mammals with rudimentary limbs, on the way to the
organisms of today but not yet there. Do not, however,
expect an apology and a retraction.
Even the vestigial limbs
[of supposed whale ancestors] present problems. By what
Darwinian process did useful hind limbs wither away' to
vestigial proportions, and at what stage in the
transformation from rodent to sea monster did this occur?
Did rodent forelimbs transform themselves by gradual
adaptive stages into whale flippers? We hear nothing of
the difficulties because to Darwinists unsolvable
problems are not important."(2)
In any case, can we be
sure that these supposed limbs really were connected with
the proto-whales? Perhaps they were just lying nearby.
I will treat this kind
of argumentation with the silent contempt that it merits
- although I would love to know where Johnson got the
idea that whales are descended from rodents. (Truly,
their ancestors were closest to the ancestors of the
herbivores like cows. Rodents belong to another branch,
along with rabbits.)
I will move on to the
question of causes or mechanisms. Here we find the new
creationists trembling with critical ecstasy. Once again
natural selection is brought out, paraded, and found
wanting. Either it is a tautology, necessarily true and
thus immune to the evidence, or it is open to checking
and has been found wanting. Supposedly, even
evolutionists recognize this, as they rush to alternative
mechanisms like Gouldian punctuated equilibria. Either
way, selection doesn't amount to much. But indeed, apart
from all of the problems with mutations, apart from the
false analogy with artificial selection, apart from the
fact that no one has ever seen it do more than the bare
minimum, in the opinion of the critics, natural selection
is conceptually flawed - through and through. It simply
cannot produce the designlike features that characterize
the world: the adaptations so necessary for life and
limb.
As so often in
discussions of this kind, we encounter the analogy of
monkeys typing Shakespeare - or rather of monkeys not
typing Shakespeare. Random hitting on a typewriter is not
going to produce Hamlet, nor is natural selection working
on random mutation going to produce organisms.
This is a false analogy.
Natural selection is not like monkeys simply hitting the
keys and, if wrong, starting again from the beginning.
Selection is cumulative. Once one has made some progress,
that stays on as backing for all subsequent tries. And
selection does not demand one particular predetermined
play, and that the best ever written. In evolution, there
is no already-decided end point. Any play will do - an
appalling farce, for instance - and all it has to be is
better than any rival. To think otherwise is to show,
truly, that you do not know what you are talking about.
Worse, it is to show that you do not know what
evolutionists are talking about.
IRREDUCIBLE COMPLEXITY
Perhaps encouraged by
their self-awarded success, the new creationists have
recently started to break from their strategy of
unrelenting attack. Thanks to biochemist Michael J. Behe,
author of Darwin's Black Box: The Biochemical Challenge
to Evolution (1996), they have started to lift the veil
from their own beliefs about origins qua science. (See
the book review in this issue.) Indeed, one might say
they have ripped the veil in twain with trumpets
accompanying: "The result is so unambiguous and so
significant that it must be ranked as one of the greatest
achievements in the history of science. The discovery
rivals those of Newton and Einstein, Lavoisier and
Schrodinger, Pasteur and Darwin' (pp. 232-233).
It is Behe's claim that
there are facts of organic nature whose origin cannot be
evolutionary. Cannot in fact be natural at all, meaning
the consequence of regular unguided law. These facts,
marked by irreducible complexity, have to be the product
of a designer, however construed.
By irreducibly complex I
mean a single system composed of several well-matched,
interacting parts that contribute to the basic function,
wherein the removal of any one of the parts causes the
system to effectively cease functioning. An irreducibly
complex system cannot be produced directly (that is, by
continuously improving the initial function, which
continues to work by the same mechanism) by slight,
successive modifications of a precursor system, because
any precursor to an irreducibly complex system that is
missing a part is by definition nonfunctional. An
irreducibly complex biological system, if there is such a
thing, would be a powerful challenge to Darwinian
evolution. Since natural selection can only choose
systems that are already working, then if a biological
system cannot be produced gradually it would have to
arise as an integrated unit, in one fell swoop, for
natural selection to having anything to act on. [p. 39]
Behe does not want to
rule out a natural origin for all irreducible
complexities, but we learn that, as the complexity rises,
the likelihood of getting things by any indirect natural
route "drops precipitously' (p. 40). As a physical
example of an irreducibly complex system, Behe instances
a mousetrap - something with five parts (base, spring,
hammer, and so forth), any one of which is individually
necessary for the mousetrap's functioning. It could not
have come into being naturally in one step and it could
not have come gradually - any piece would not function
properly and any part missing would mean failure of the
whole. It had to be designed and made by a conscious
being: a fact that is true also of organisms. Behe
instances the phenomenon of blood clotting as an organic
example of such intelligent design. "The purposeful
arrangement of parts" is the name of the game (p.
193).
As it happens, Behe's
choice of a mousetrap as an exemplar of intelligent
design has been somewhat unfortunate. All sorts of parts
can be eliminated or twisted and adapted to other ends.
There is no need to use a base, for example. You can just
attach the units directly' to the floor: a move that at
once reduces the trap's components from five to four. But
even if the mousetrap were a terrific example, it would
hardly make Behe's point. No evolutionist ever claimed
that all of the parts of a functioning organic feature
had to be in place at once, nor did any evolutionist ever
claim that a part used now for one end had always to have
that function. Ends get changed, and something introduced
for one purpose might well take on another purpose: only
later might it get fixed in as essential.
Against the mousetrap,
let me take the example of an arched bridge, with stones
meeting in the middle and with no supporting cement. If
you tried to build it from scratch, the two sides would
keep collapsing as you started to move the higher stones
into the middle. What you must do first is build an
understructure, placing the stones on it: then, when the
stones are pressing against one another in the middle,
you can remove the understructure. It is now no longer
needed; although, if you were not aware that it had once
been there you might think that it is a miracle that the
bridge ever was built. Likewise in evolution: some
pathway (say) exists; a set of parts sit idle on the
pathway; then these parts link up; and finally the old
pathway is declared redundant and removed by selection.
Only the new pathway exists, although without the old one
the new one would have been impossible.
Behe is a real
scientist, but his case for the impossibility of a
small-step natural origin of biological complexity has
been trampled upon contemptuously by the scientists
working in the field. They think his grasp of the
pertinent science is weak and his knowledge of the
literature curiously (although conveniently) outdated.
For example, far from
the evolution of clotting being a mystery, the past three
decades of work by Russell Doolittle and others has
thrown significant light on the ways in which clotting
came into being. More than this, it can be shown that the
clotting mechanism does not have to be a one-step
phenomenon with everything already in place and
functioning. One step in the cascade involves fibrinogen,
required for clotting, and another, plaminogen, required
for clearing clots away. Doolittle writes:
It has become possible
during the last decade to "knock out" genes in
experimental organisms. "Knock out mice" are
now a common (but expensive) tool in the armamentarium of
those scientists anxious to cure the world's ills.
Recently the gene for plaminogen was knocked out of mice
and, predictably, those mice had thrumboric complications
because fibrin clots could not be cleared away. Not long
after that, the same workers knocked out: the gene for
fibrinogen in another line of mice. Again, predictably,
those mice were ailing, although in this case hemorrhage
was the problem. And what do you think happened when
these two lines of mice were crossed? For all practical
purposes the mice lacking both genes were normal.
Contrary to claims about irreducible complexity, the
entire ensemble of proteins is not needed. Music and
harmony can arise from a smaller orchestra.[3]
Suppose you accept
Behe's conclusion about the existence of a Designer. What
precisely is the role of this Designer? Behe is careful
not to identify. it with the Christian God. But let us
suppose such a Designer does exist and is at work
producing irreducibly complex organisms. Who then is
responsible when things go wrong? What about
mal-mutations causing such awful things as Tay-Sachs
disease and sickle-cell anemia? Behe says that raising
this problem is raising the problem of evil, which is so.
But labeling the problem does not make it go away.
DARWINISM AS RELIGION
The new creationism is
no more effective than any of the earlier versions. But I
doubt that my counter-arguments will have much effect,
and not simply because these critics are blind or biased.
There is more at stake than has hitherto been
acknowledged. The real problem with Darwinism for the new
creationists lies not in its status as science. The real
objection is to Darwinism as religion.
To the new creationists,
Darwinism is a wolf in sheep's clothing. Secular religion
in the clothing of empirical science. Darwinism is based
on a philosophy - the philosophy of
"naturalism." "Darwinian evolution is an
imaginative story about who we are and where we came
from, which is to say a creation myth. As such it is an
obvious starting point for speculation about how we ought
to live and what we ought to value."(4) From here it
is but a short step to sex, drugs, and contempt for
capitalism.
If there is a connection
between fact and value, between Darwinism and people's
systems of value, it is far from obvious that this has to
be one of freedom and permissiveness, of sexual laxity,
and of personal autonomy. There have been Darwinians of
the political and moral and religious right of a kind to
make Johnson and his fellows look like escapees from the
1960s. Sir Ronald Fisher, for example, is certainly the
most distinguished theoretical biologist in the history
of evolutionary thought. He was also a Christian, a
member of the Church of England, a conservative, a member
of the British Establishment, and one whose social views
were somewhere to the right of Louis XIV.
Johnson draws a
distinction between "methodological
naturalism," the attitude by the scientist that one
should explain as far as is possible in terms of natural
unbroken laws, and "metaphysical naturalism,"
the belief that unbroken-law-governed material is all
there is to existence. Unfortunately, argues Johnson, the
scientist starts off down the path of methodological
naturalism and ends up with metaphysical naturalism. And
this spells atheism, which in turn leads to complete
moral license.
There are people who are
fully committed to methodological naturalism, believing
that evolution is true, and who yet are theists in as
meaningful a sense as one could ever wish. The present
pope - a man, incidentally, who is notoriously tough on
such things as sexuality - is precisely such a person.
Recently, Pope John Paul II has come out four-square in
favor of evolution and yet he reserves to God His
traditional full power of action.
Finishing the argument
against Johnson, the evolutionist notes that his moral
worries are no more well taken than his fears for theism.
Even if Darwinism were to imply atheism, there is no
logical reason to think that such a person would thereby
be committed to moral nihilism. In the last century,
although people like Thomas Henry Huxley described
themselves as agnostics, they were certainly atheistic
with respect to Johnson's kind of God. Yet they were
moral-boringly and obsessively moral - in a very
conventional manner. Huxley met and admired George Eliot;
but, given that she lived openly with a man to whom she
was not married, he would not invite her to his own house
to meet his wife and children.
The new creationists are
fight in seeing evolutionary ideas as a threat, although
they are hardly right in laying at the evolutionists'
door all of the moral moves of modern society. I suspect
that, like most of us, evolutionists reflect their place
in this society as much as they create it.
The new creationism is a
slicker product than the old creationism. Exploring the
fears of its exponents leads us to think more carefully
about Darwinism and its nature and limits. But,
ultimately, there is nothing to challenge Darwin's work.
It is time, as the title of my book suggests, for Taking
Darwin Seriously.
Notes
1. D. Berlinski,
"The deniable Darwin," Commentary June 1996:
19-29.
2. P. E. Johnson, Darwin
on Trial, 1991. (Washington, D.C.: Regnery Gateway) p.
87.
3. Russell F. Doolittle,
"A delicate balance," Boston Review 22 (1997):
no. 1: 28-29.
4. Darwin on Trial, p.
133.
Michael Ruse is
Professor of Philosophy and Zoology at the University of
Guelph, and the author of Taking Darwin Seriously (B.
Blackwell, 1996) and But Is It Science? The Philosophical
Question in the Creation/Evolution Controversy
(Prometheus, 1996). He participated in a debate on
creationism and evolution on "Firing Line" in
December 1997.