Darwinism: Science or Philosophy

MY PRIMARY CRITICISM of Leslie Johnson's interesting paper will, I'm sure, be unexpected, even thought impolite. Her primary focus is irrelevant to the topic of this symposium. But that irrelevance is highly significant. It is clear that I need to justify such an outrageous statement. Dr. Johnson makes an eloquent plea for the adequacy of the fossil record in documenting descent, and that is just the problem. Common descent is not particularly relevant to our theme, the reason for the acceptance of neo-Darwinism. "Evolution" and "Darwinism" are not synonyms, and Darwinism is not a theory that creatures share common ancestors-even structurally very different ancestors-it is rather a theory of how those creatures became different. Darwinism is a theory of mechanism, not a proposed historical scenario.

I realize that words like evolution and Darwinism have been used like the walnut shells in a shell game to obscure distinctions and to persuade the faint in heart. Evolution has at least been used to mean change, mechanism, history, paradigm, and world view, more linguistic freight than any word can meaningfully carry. However, neoDarwinism-the Modern Synthesis-is supposed to be a theory of a mechanism by which genotypes (and the phenotypes they produce) can be transformed. Evidence that links two different forms of life in common descent simply describes a phenomenon that we need to explain.

This probably seems like nit-picking to a 1990s audience, but it would have made perfect sense to one in the 1890s. The Modern Synthesis has been so generally accepted that it has practically become synonymous with all the various meanings carried by the word evolution. To evaluate why this confusion exists, we must disentangle those meanings

A quick trip to pre-Darwinian England can help to clarify the confusion. One hundred and fifty years ago, according to Gillespie (1979), most naturalists accepted the idea of common ancestry, but they differed on how new forms arose. The Establishment at Oxford (Buckland, for instance) evidently thought that God occasionally remodeled an existing form into a perfectly adapted new type (Rupke, 1983). The Radical Materialists such as Grant and Knox followed Lamarck in considering matter itself energized with an intrinsic tendency for unifomm development (Desmond, 1989). The followers of German Naturphilosophie (Richard Owen, for instance) held the theory that autonomous extra-material archetypes shaped lineages progressively into their own images (Desmond, 1982). All the schools (with the exception of Louis Agassis) viewed fossil sequences as demonstrations of common descent. They differed on the nature of the power that shaped biological form, but not on whether things shared common ancestry. One further note: although they differed in their philosophies of nature, each school had both Christian and non-Christian adherents.

According to historian James Moore (1982), however, around 1840 a new movement of young middle-class reformers calling themselves "Naturalists" appeared. This group as young adults typically changed their creed from Christianity (which they felt was morally bankrupt) to one based on "Nature." They were "poets and lawyers, doctors and manufacturers, novelists and naturalists, engineers and politicians." The group included such well-known individuals as George Eliot, Herbert Spencer, Matthew Arnold, Francis Galton, J. A. Froude, G. H. Lewes, Charles Bray, Alfred Lord Tennyson, John Tyndall, F. W. Newman, A. H. Clough, Harriet Martineau, F. P. Cobbe, and, of course, T. H. Huxley. Moore shows that the central feature of this new creed was the redefinition of human nature, society, order, law, evil, progress, purpose, authority, and nature itself in terms of the Naturalists' particular view of Nature, as opposed to the Christian Scriptures. In fact, they tended to attack the Christian Scriptures as the true source of societal evil. God, if he existed, was to be known only through the Nature which he made. Thus, according to Moore (1982) and Young (1980), "positivism" was not primarily a methodology for science, but a religious movement that sought to replace the cultural dominance of the Established Church.

Charles Darwin launched his theory of biological change in this context. He proposed a mechanism for the appearance of new forms that did not depend on any pre-existing or exterior shaping forces. The environment became the only needed constraint. It was a theory of strategic importance for the Naturalists, particularly for the "X" club, Huxley's "Young Guard" party in science.

The significance of a mechanism can be understood only within the world views of its proponents. The "Naturalism" that initially proposed and supported Darwin's mechanism was both a world view and a social movement. These individuals viewed the world as autonomous, and the Darwinian mechanism as autonomous creator. The scientific members of this movement, Huxley's "X" club, were engaged in a successful campaign to wrest the university chairs in the sciences from the clergymen/naturalists of the Established Church. The ability of Darwinism to replace the divine with a natural process was a critical support.

Turner (1978) has proposed that this fabled Victorian conflict was primarily a "professional" struggle for scientific autonomy and authority, a struggle between the "professionally" trained and validated scientists and the Anglican dons. Still, if the professionally validated "scientist" is viewed as the only one who can adequately understand nature, and if Nature has replaced Scripture as the source of moral and teleological truth, ipso facto the scientist has replaced the priest. Thus, the "professional" position at stake was as much the pulpit as the lectern.

Thus, although in reality it is just a simple proposal of natural processes, Darwinism historically was accepted by the Naturalists by philosophical preference. Huxley himself did not accept its scientific inference for the fossil record until after 1864 (Desmond, 1982). Indeed, as a "scientific inference," a description of material cause, other schools of thought also accepted Darwin's mechanism, but they considered it inadequate as an explanation of important biological change. Neo-Lamarckians such as Cope, and Mutationalists like De Vries, held competing theories of mechanism for morphogenesis.

In particular, Christian theists who held the universe to be governed at all points, rather than autonomous at all points, simply took the mechanism to be an aspect of God at work (Livingstone, 1989). This view I want to highlight for a moment, since it directly bears on the "blind watchmaker" question. Such men included the "American Darwin," Harvard botanist Asa Gray, who introduced and defended Darwin's theory to America, and the conservative Princeton theologian, B. B. Warfleld. But Gray said, "If Mr. Darwin believes that the events which he supposes to have occurred . . . were undirected and undesigned . . . no argument is needed to show that such a belief is atheistic." Warfeld (1988) commented:

Mr. Darwin's difficulty arises on one side from his inability to conceive of God as immanent in the universe and his consequent total misapprehension of the nature of divine providence, and on the other from a very crude notion of final cause which posits a single extrinsic end as the sole purpose of the Creator. No one would hold to a doctrine of divine "interpositions" such as appears to him here as the only alternative to divine absence. And no one would hold to a teleology of the raw sort which he has here in mind-a teleology which finds the end for which a thing exists in the misuse or abuse of it by an outside selecting agent.

It is however neither evolution nor natural selection which give Darwinism its peculiar character and importance. It is that Darwin rejects all teleology, or the doctrine of final causes. He denies design in any of the organisms in the vegetable or animal world."

Darwin did not publish his rejection of the design argument until 1868 at the end of Animal and Plants under Domestication. Using the analogy of a building constructed from the stone fragments at the base of a precipice. Darwin stated:

In regard to the use to which the fragments may be put, their shape may be strictly said to be accidental . . . Can It be reasonably maintained that the Creator intentionally ordered, if we use the words in any ordinary sense, that certain fragments of rock should assume certain shapes so that the builder might erect his edifice? . . . we can hardly follow Professor Asa Gray in his belief "that variation has been led along certain beneficial lines" . . . On the other hand, an omnipotent and omniscient Creator ordains everything and foresees everything. Thus we are brought fact to face with a difficulty as insoluble as is that of free will and predestination.

The Naturalists succeeded. The "Young Guard" used the trappings of religion to sacralize their "science." Three centuries of cooperation between science and religion were forgotten and their history was rewritten as "warfare." Hymns to nature were sung at popular lectures before the giving of "lay sermons" by a member of Galton's "Scientific Priesthood." Museums were built to resemble cathedrals, and following frantic string-pulling by Lubbock (a member of the "X" club) Charles Darwin was buried in Westminster Abbey. The new church was established (Moore, 1982).

In her paper Dr. Johnson objects that many scientists are religious, which is of course true. But, the ongoing success of "scientific naturalism" as a religious movement can be judged by the present general acceptance by "Science" and by the "Public" of the pronouncements of those "true believers" of the "church scientific" who still exist and evangelize among us. E. O. Wilson (1978) is clearly acting in a clerical role when he tells us:

This mythopoeic drive [i.e., the tendency toward religious belief] can be harnessed to learning and the rational search for human progress if we finally concede that scientific materialism is itself a mythology defined in the noble sense . . . Make no mistake about the power of scientific materialism. It presents the human mind with an alternate mythology that until now has always, point for point in zones of conflict, defeated traditional religion . . . The final decisive edge enjoyed by scientific naturalism will come from its capacity to explain traditional religion, its chief competitor, as a wholly material phenomena.

The Biblical literalist, the Evangelical revivalist, the political visionary and even the slightly perturbed old priesthood of the established theologies turn to the new priesthood [of science] for reassurances that their beliefs have not been left behind in the wake of the revolutionary revelations of science. The new priesthood has not been found wanting. Sometimes with formulae, sometimes with rhetoric, but always with science, the reassurance is dispensed.

In such a climate, it is a trifle hard to be objective with the data- which are all viewed as support for the dominant paradigm/world view; hence, Dr. Johnson's use of the evidence for descent.

But what do we need from the fossil record if we are to test for the adequacy of Darwinism (defined as mechanism)? Neither proof for descent nor for transformation; they might have other causes. Rather, we need evidence for the action of the environment in selecting that form, evidence that the environment has acted as a pattern-fitting mechanism-that is, evidence of the causes that produce morphological change. And if we want to test the blind watchmaker world view, we need evidence that demonstrates that such changes are unguided. We must explain the cause and pattern of the appearance of biological novelty. In that light, I have a few other comments or questions.

First, a minor point. It is true that new fossils fit the patterns predicted by the evolutionary sequence (but that's not particularly relevant). That pattern, however, was proposed long before the general acceptance of descent with transformation, not to speak of Darwin's theory. Those who proposed it were clearly working from some sort of hypothesis other than complete randomness. No one has ever thought that, and using it to "test" for evolution is testing against a straw-man. How can you know where groups would be placed if they arose independently? Why suppose random placement? Would not an intelligence be the expected source of new groups in such a case? Why would an intelligence use a pseudo-random scatter of appearances? The fact that such groups fit into the accepted patterns is proof only for some sort of shaping pattern-it is not even proof of descent.

Second, the major support adduced by Dr. Johnson for the neoDarwinian hypothesis is the model world created by Thomas Ray (1991) of the University of Delaware. As an old "model builder," I would love to get my hands on Ray's intriguing model. Nevertheless, I don't think that it is an adequate proof of the Darwinian hypothesis. Models never are. Rather, it explores the implications of its instruction set-and that is the equivalent of "raw" fitness values, reproductive information with no tie to a phenotype. The world of Ray's critters, the computer itself must be programmed into the instruction set for it to be a real equivalent. Ray's computer is more than a coherent and limited environment. With "energy" gaining and "replicative" machinery built into the computer, and with those fundamental aspects of the model unable to be mutated, the computer is the equivalent of an infected cell, an electronic host in which viruses live. Maynard Smith (1992) considers it the equivalent of an "RNA" world, with no distinction between phenotype and genotype. But, an RNAzyme has both: nucleotide sequence (genotype) and molecular surface (phenotype). In Ray's world, the reproductive "phenotype" is built into the computer, and the "virus" just gives it instructions.

Also, Ray's critters produce no encoded morphology. The various critters produced vary only in their particular variant of the programmed commands for "reproduction." Although the outcomes are intriguing, all the complexity produced is "economic" rather than "morphological." The model does suggest that parasitism is a logical and necessary implication of a world with reproduction, rather than an ethical issue. But, the model is not truly open ended. If it was, Ray would not have to be planning to add new instructions for sex and multicellularity. The program would write them for itself. It would produce its own Cambrian explosion (Lewin, 1992).

Two final notes: to avoid being swamped by inviable changes, and thus to allow mutants that could survive, Ray specifically limited his instruction-set to 32 possible mutant changes from a possible instruction-set of 1011 But even that full instruction set is equivalent to the probability space of only 37 DNA bases. Thus, this random walk occurs in an unrealistically limited probability space.

In addition, the genomes of flesh-and-plasma organisms contain cybernetically error-checked programs for the production of morphologies. Thus, real genomes constrain encoded instructions of at least two classes, prescriptive and adaptive. Ray's critters have neither. Fascinating they are, significant in some ways, but they are no particular proof of the ability of neo-Darwinian mechanisms to produce novel structures.

Finally, Dr. Johnson defends evolution in terms of its importance for biology, pointing to its unifying, predictive, and productive capabilities. That statement raises intriguing questions about the nature of science. Is it true that biology cannot live without evolution, that (to quote Dobzbansky) "nothing in biology makes sense except in the light of evolution"?

First, is it the unifying theory in modern biology? Why not cell theory? or molecular energetics? or hierarchy theory? or ecosystem dynamics? or cybernetic control theory? The fact that a theory applies to all living things does not mean that it is the essential organizing framework. In reality, what is probably meant by evolution in this "unifying" context is simply philosophical materialism, but that is general philosophy rather than science.

Second is it all that predictive? It is true enough that Sereno and Chenggang's (1992) new birds fall into the right gap, but that is not an effective logic for rejecting a theory that makes the same predictions. For instance, Richard Owen's nineteenth century theory of metaphysical archetypes would have "predicted" the same findings (or at least their probability). As I have already pointed out, the prediction of a designed universe is not the appearance of new morphologies in a random scatter.

Third, is the productivity of the theory evidence for its validity? The evidence of history is that any new and widely accepted paradigm leads to a furious round of research and scientific advance. It was, after all, the "higher anatomy" of the idealists that led to the science of comparative anatomy. Certainly it is not the productivity of the theory of the spontaneous generation of life that has kept that field so busy.

In reality, we all do science caught between our world views and the hard-edged facts of the real world. But that tension is buffered by a hierarchy of progressively more inclusive theoretical lenses through which we view the world. We investigate the real world under the guidance of our recognition frameworks. As Stephen Gould put It (1980):

First, facts do not come to us as objective items seen in the same unambiguous way by all reasonable people. Theory, habit, prejudice and culture all influence the facts we choose to observe and the way in which we perceive them. Second, the construction of theories is not a 'second story operation in science, an activity to be pursued after constructing a factual ground floor. Theory informs any good scientific work from the very beginning; for we ask questions in its light, and science is inquiry, not mindless collection. Moreover, the sources of theory are manifold; new ideas arise more often by the creative juxtaposition of concepts from other disciplines. . . than from the gathering of new information within an accepted framework.

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