Answering the creationists: where they go wrong - and what they're afraid of.
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.
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.
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.
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.
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.
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|Date:||Mar 22, 1998|
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