On the Origin of Stasis (Part IV)

Philosophical naturalism requires that nature be fully continuous. The history of life must be represented as a tree. All life must have descended from a common ancestor. All genetic change must ultimately be the result of purely unguided, materialistic processes. Theism, on the other hand, has fewer restraints. Life may be either continuous or discontinuous. It follows that life may be modeled as either a tree or a forest. (It should be noted that a forest of life accommodates continuity among the lower taxa and discontinuity among the higher taxa: Taxa, plural of taxon–a biological category. Lower to higher taxa: species, genus, family, order, class, phylum, kingdom.)

Under a theistic or agnostic worldview it is incumbent upon the scientist to actually do more science. It is not sufficient to simply assume common ancestry. Scientific tests must be developed which may reject the hypothesis of common ancestry for the higher taxa and instead reveal the presence of natural discontinuities. The hypothesis of a random origin of genetic information must also be put to the test. The origin of 40-50 phyla within the five to ten million-year window of the Cambrian explosion, for example, must be shown to be mathematically and biologically plausible if the designer is chance. If nature is discontinuous then there may even be natural processes which inhibit major evolutionary change from occurring and which explain the pervasive patterns of natural history and higher taxon-level stasis.

Although Michael Denton believes nature to be continuous, his account of the transformation of the scientific community from postulating a discontinuous model of nature to a continuous one after 1859 is well worth reviewing. Whether nature turns out to be continuous or discontinuous is not the point. The point is that a discontinuous model is no less scientific than a continuous one. The ultimate question is which model most accurately represents the data?

Biology in the early decades of the nineteenth century was dominated by the idea that the organic world was a fundamentally discontinuous system in which all the major groups of organisms were unique and isolated and unlinked by transitional forms. ... Where there was variation, it was only trivial variation within the clearly defined limits of the species or type. Thus to the naturalists of the nineteenth century the basic order of nature was static and discontinuous, very different from the dynamic continuous model which was later to become axiomatic for most biologists after 1859. [Denton]

Before 1859 it was fashionable and intellectually respectable to view the organic world as a discontinuous system–the result of successive creation interventions in the history of the world. After 1859 it became intellectually respectable to view life as the natural product of purely natural processes operating over long periods of time. Changing one's interpretation of the world is not, however, the same as establishing a new fact. The facts were the same in 1850 as they were in 1870, only the perception of them had changed. (Ref. , p. 74)

The so-called typological model of nature adhered to by biologists early in the (19th) century had a considerable degree of empirical support.... [T]he work of the great nineteenth century comparative anatomists such as Cuvier and, later, Owen had shown that the living world could be considered divided into distinct types or phyla and that organisms clearly intermediate between different classes were virtually unknown.

Comparative anatomy had also revealed that organisms were integrated wholes in which all the components were coadapted to function together; and this seemed to many to preclude any sort of major evolutionary transformation. As William Coleman, an authority on Georges Cuvier, points out:

The organism, being a functionally integrated whole each part of which stood in close relation to every other part, could not, under pain of almost immediate extinction, depart significantly from the norms established for the species by the first anatomical rule.

A major change, for example, a sharp increase in the heart beat or the diminution by half of the kidney and thus a reduction in renal secretion, would by itself have wrought havoc with the general constitution of the animal. In order that an animal might persist after a change of this magnitude it would be necessary that the other organs of the body be also proportionally modified. In other words, an organism must change en bloc or not at all. Only saltatory modification could occur, and this idea was to Cuvier, as it is to most modern zoologists, but for very different reasons, unverified and basically absurd. Transmutation by the accumulation of alterations, great or small, would thus be impossible. [Coleman, W. (1964) Georges Cuvier: Zoologist, Harvard University Press, Cambridge, Mass, pp. 172-73 a quoted in Ref. , p. 18]

When the appeal of the scientific paradigm and the natural desire of the scientific community to extend the range of scientific explanation are taken in conjunction with all the various intellectual trends and fashions of the later Victorian era, it is in retrospect perfectly easy to understand how Darwin's theory proved irresistible even though, as Darwin himself admitted, the actual empirical evidence was insufficient, and there was absolutely no evidence that any of the major divisions of nature had been crossed in a gradual manner. If nature was to be explained by natural processes, she had to be continuous. (Ref. , p. 73)

As the years passed after the Darwinian revolution, and as evolution became more and more consolidated into dogma, the gestalt of continuity imposed itself on every facet of biology. The discontinuities of nature could no longer be perceived." (Ref. , p. 74)

Given the morphological discontinuities among the higher taxa, the discontinuous appearance of the phyla in the Cambrian explosion, the reverse order of geological succession, the examples of irreducible complexity found at the molecular level of life, [[Beh] and the problem of homoplasy (functional or developmental homologies, i.e., structures having similarities, that cannot easily be explained by common descent) scientists must revise the pre-Darwinian model of nature, incorporating neo-Darwinian microevolution, speciation, punctuated equilibria, and other mechanisms which can account for the continuity and diversity of the lower taxa.

Beyond that, scientists will need to gain a much greater understanding of the processes underlying stasis. Species stasis commonly continues for millions of years, periods of time for which environmental constancy does not seem possible. Indeed, species stasis often appears to persist despite evidence for environmental change. Natural selection is obviously only a part of the whole picture. Internal genetic and developmental mechanisms may play an even greater role in maintaining higher taxon-level stasis by inhibiting transitional forms from developing in the first place.

If Mivart was correct in concluding that natural selection is incompetent to account for the incipient stages of useful structures, we can only criticize him for not taking his idea far enough. He could have developed a theory of "macrostasis" and established natural selection as a key mechanism underlying the phenomenon of morphological stability and the mechanism which explains the lack of transitional forms in the fossil record. Had he done so, we might have emerged from the nineteenth century with two major theories of biological change: one accounting for minor evolutionary change and the common ancestry of the lower taxa and another accounting for the stability of the higher taxa. More importantly, we would have entered the twentieth century with theories that more accurately reflected the empirical data.

As we enter the twenty-first century we should pause and re-examine our presuppositions as well as our data. We must be careful not to slip into scientism and must constantly strive to most accurately describe nature even if it means discarding some of our most cherished beliefs. As Pierre-Paul Grassé, past President of the French Academie des Sciences and editor of the 35 volume Traité de Zoologie, expressed it:

Today our duty is to destroy the myth of evolution, considered as a simple, understood, and explained phenomenon which keeps rapidly unfolding before us. Biologists must be encouraged to think about the weaknesses and extrapolations that theoreticians put forward or lay down as established truths. The deceit is sometimes unconscious, but not always, since some people, owing to their sectarianism, purposely overlook reality and refuse to acknowledge the inadequacies and falsity of their beliefs. [Grassé]

We must bear in mind that just because neo-Darwinian evolution is presently the most accepted naturalistic explanation of origins, we should not assume that it is necessarily true. Likewise, just because creation involves non-natural processes, we should not assume that creation events–whether sudden or gradual–have not occurred. It would be unreasonable to assume so. Nature may turn out to be discontinuous after all. Creation events may not be subject to scientific investigation, but stasis most definitely is. Recall that Gould said, "Stasis is data," [Gould] meaning "no evolution."

In retrospect, it seems as though Darwinists have been more concerned with the religious or philosophical question of explaining the design found in nature without a designer than the empirical data of natural history. Darwin's general theory of evolution may, in the final analysis, be little more than an unwarranted extrapolation from microevolution based more upon philosophy than fact. The problem is that Darwinism continues to distort natural science.

If it turns out that natural selection plays a more dominant role in the phenomenon of higher taxon-level stasis than it does in major evolutionary change, the irony will be that Darwin himself predicted this possibility over 130 years ago.

I am well aware that there is scarcely a single point discussed in this volume on which facts cannot be adduced, often apparently leading to conclusions directly opposite to those at which I have arrived. A fair result could be obtained only by fully stating and balancing the facts on both sides of each question, and this cannot possibly be done here. [Darwin]

Because creation events are historical possibilities, it is entirely possible that natural processes alone are insufficient to account for the origin of life and all genetic information. Although philosophical naturalism requires a cosmos without a creator, science does not. Scientists working within the confines of methodological naturalism could, in fact, discover natural processes that prevent major evolutionary change from occurring, processes that explain the pervasive patterns of higher taxon-level stasis and discontinuity.

References
Behe, Michael (1996) Darwin's Black Box: the biochemical challenge to evolution, The Free Press, New York.