A positive case against Darwinism by a co-belligerent
Reviewed by David Snoke
The Discovery Institute has a long history of sponsoring and collaborating with a large number of highly intelligent, fascinating scientists who stand outside traditional Christian belief as well as outside the mainstream of evolutionary science. In keeping with this tradition, they have recently published Evolution: A Theory Still in Crisis, by Michael Denton, a followup to his famous book thirty years ago, Evolution: A Theory in Crisis, which influenced a whole generation of scientists to question the standard paradigm of evolution. In this book, Denton is not mainly just updating his previous arguments with data from the past three decades in the rapidly advancing fields of evolutionary and developmental biology (“evo-devo”) and genetic paleontology. His main purpose in the book is to present a comprehensive, positive case for his own view of how the diversity of life came about. His view is not the same as the intelligent design view promoted by the Discovery Institute, but many of his points could be equally seen as supportive of intelligent design.
In short, his view is that there are pan-phylogenic Types, or Forms, which exist in nature, to which life spontaneously conforms. This view sounds a lot like neo-Platonism, which, following Plato, posits a spiritual world of Ideals which then instantiate themselves in nature. But Denton explicitly avoids spiritual implications and insists on this view as a purely physical and materialist theory. His hero is Richard Owen, an early pre-Darwinian evolutionist, who posited the same view.
We are all so programmed by the current evolutionary debate to see Darwinian evolution as the only viable materialist theory that it is hard to understand at first what Denton is proposing, if not intervention from a spirit world, and it is hard to grasp that there were evolutionists who preceded Darwin, with strong arguments against Darwin’s ideas. To understand Denton’s view (and Owen’s) it is crucial to realize that it is first and foremost an empirical theory. Science has a long tradition of empirical theories which simply state the facts in unifying language without proposing any mechanism at all to explain them. Thus, for example, Newton famously proposed that gravity force could act at a distance, without proposing any explanation why. We are all so used to Newton’s laws now that we forget how empirically driven it was. The same empirical approach was used to build the Periodic Table of chemistry, long before quantum mechanics explained why it has the form it does. In the same way, Denton, following Owen, draws us to look at a glaring and obvious fact of nature: that living organisms do not exist in a continuum of small differences with gradual transitions between them; rather, they exist in highly distinct types and forms, with specific identities and unique features for each type. Thus, for example, mammals all have four limbs, five digits per limb, two eyes, mammary glands in pairs, etc. These patterns persist over hundreds of millions of years despite all manner of selective pressure in different directions.
Darwinian evolutionists are familiar with these properties, of course, and have a standard explanation that they are leftover vestiges from archetypal ancestors. Against this, Denton has two main arguments. First, the record strongly supports the view that new Forms appear suddenly, without precursors. This is known as “saltation”—the sudden appearance of a fully formed new structure. In all of the cases we know, the “transitional forms” between one type of organism and another do not consist of creatures with half-novelties, but rather, creatures with whole and complete novelties. Their transitional nature is identified because they have a subset of a larger set of several wholly novel features belonging to later descendents. But in each step that we see along the way, that which is new is whole and complete. The problem this creates for Darwinian evolution is similar to what is called a “topological argument” in physics. There are some things that can be continuously transformed into other things, while some things cannot. In the canonical example, a coffee cup can be transformed continuously into a doughnut, but not into a saucer. In the same way, all feathers are tubular, which requires a follicle with circular form, while reptile scales are flat sheets. Topologically, a flat sheet cannot be continuously transformed into a tube. (It was fascinating to me to hear that the dinosaurs-acquiring-feathers story actually creates new problems for Darwinism.) There are also more generalized topological arguments. Some molecular cycles in the cell are circular—the so-called “chicken-and-egg problems” in which element A is required to create element B, and B is required to create C, but C is required to create A. These loops therefore have the same toplogical problem of lack of continuous generation from a prior process.
The transitional forms which indicate common descent also therefore create huge problems for gradual change via Darwinian selection as a mechanism. The most plain reading of the data is “descent with saltation.” This occurs at every level. New organs occur suddenly, new processes occur suddenly (such as human language), and new genes occur: in every form of life there are whole genes (known as ORFans) that appear to be utterly unique to that form, with no homolog in any other type of creature. In some cases, even when genes from an ancestor are used, they are pressed into service to perform utterly new functions via the sudden appearance of a completely new set of switches and timers.
Denton’s second argument against the Darwinist understanding of the Forms is the “robustness” of these Forms—after their sudden appearance, they endure for tens to hundreds of millions of years with little or no change. This is the case even though these Forms in many cases seem to have very little adaptive value—for example, does having five fingers or toes really make a person more fit than having six, or four? From a Darwinian perspective, the less a feature is pressured by natural selection, the more variable it should be.
Another type of of robustness of the Forms is in their origin: when radically different processes give rise to the same forms. This is called “convergent evolution” in standard Darwinian evolution, but giving it a name doesn’t solve the problem it creates. One might allow that adaptation to similar conditions could give features with similar functions, but it is not just the function, but the overall forms which are the same, down to striking detail. For example, all insects have similar form, with head, body, and thorax and six legs, but in the embryo, these forms are reached by radically different paths (sometimes all appearing together, sometimes in different orders) by processes involving completely different genes. If radical differences can occur in embryonic development, why do they not lead to changes in the overall form, such as eight or ten legs? Similarly, wholly different species can converge on the same forms down to small detail. Mammals and birds both have four-chamber hearts, even though their most recent common ancestor did not. One must posit in many, many cases that radically different evolutionary paths led to the same forms, and in somes cases, even the same gene codings being re-invented from scratch. Robustness is also seen in the size scaling of all kinds of species, such as very big beetles and very small beetles. It is not so simple as issuing a command “make the beetle bigger.” All the parts must be separately triggered to get bigger, and the relative size changes must be commensurate with each other, lest one have a small beetle with huge legs, etc. We’ve also all seen the way people grow from tiny humans in the womb, with all the parts growing at the same proportionate rate—this requires enormous coordination of signaling.
Stephen Jay Gould recognized the stability of forms discussed by Denton, and promoted the notion of “punctuated equilibrium.” In this view, the jumps to new forms are continuous transitions, the products of accelerated Darwinian evolution on geologically short time scales. Denton, while having much in common with Gould, argues that the jumps could not have been continuous. Gould appears to have recognized this in some cases, but never departed fully from Darwinian orthodoxy. Denton argues for radical saltation, perhaps hundreds of thousands of times in the history of life.
How could such radical saltation of new forms come about? For those adhering to intelligent design, the saltation events could be miraculous interventions. Is 100,000 too many? Why so? What is the maximum number of interventions we may impose on God?
Denton does not invoke intelligent miraculous intervention. He favors a physical, materialist mechanism. As discussed above, his argument does not rest on having actually found such a mechanism. His argument is entirely empirical—the novelties of new Forms cannot have been acquired gradually via natural selection, so we must look for something else. Denton favors some version of “self-organization” along the lines promoted by Ilya Prigogene and Stuart Kaufmann. Somehow, internal physical forces conspire to create something completely new. The analogy often used is the formation of ice from water when the temperature drops below a critical threshold.
Here is where I as a condensed matter physicist must throw cold water on Denton’s proposal. I am familiar with the physics of self-organization and pattern formation, and can say that despite the grand claims made for it, that line of research is nearly dead, and hopeless as a way of generating life. The easiest way to see this is to think about the information involved. The information in a crystal of ice, or in a self-organized pattern of clouds, or a fractal, etc., is quite small—in terms of Kolmogorov information, it would take a very short computer program to specify these regular patterns. But life is incredibly information-rich—as Denton says, it is a “third infinity,” not the infinitely large or the infinitesimal, but unbounded complexity. Every complex mechanism we figure out unlocks more to discover. Spontaneous pattern formation works for regular patterns like crystals and waves, but simply can’t carry the freight of generating the vast amounts of specified information in living organisms. Denton doesn’t address this problem, but suggests in a hand-waving way that an adequate theory of self-organization of life could require extreme fine-tuning of the physical laws in some way.
A third possible cause of the prolific saltation, which Denton alludes to but does not seem to favor, is that all of the dramatic changes were pre-programmed in the very first living organism. In this view, the saltation events are like the unfolding of a Transformer toy into a new state. The Transformer toys were well designed to allow radical changes into new forms—similary, the unfolding of the story of lifemay come from front-loaded information. There is actually genetic evidence that this has happened, with elements that exist in ancestor life forms and are triggered into operation only in the descendents. The amount of design needed to pre-program this, not just for one transformation but for the whole tree of life, is staggering, but it would not be beyond the powers of an omniscient God.
The idea of robust Forms is worth examining for the Christian. As Denton notes, much Christian thinking has been as utilitarian as Darwinist thinking. We tend to assume that everything in living systems must have a useful function. Perhaps some things, especially overall architectures, have their particular form not for function but for beauty or diversity. This leads to, for example, a helpful way of looking at the the problem of male nipples. If we ask “what are male nipples for?” we are assuming a fully utilitarian view of living forms, and can get into knots trying to decide what they are good for, or if God has made a mistake. If we adopt a view of Forms, we can say that male nipples exist because the proper form for human bodies is to have nipples there.
The idea of Forms also makes a difference when think about race and racism. Darwinism has always had an ugly flirtation and sometimes open marriage with racism. If all of life is a continuum of gradual changes, then it makes sense that various subgroups of humans would be at different stages in evolutionary development, some closer to apes and others closer to the next upward step. Darwin argued in The Descent of Man that “lower” versions of humans such as Hottentots were proof of his theory of evolution. But Denton makes the case that, like other creatures, humans have had a stable single Form since they first existed, with all the basic gifts of language and culture in all geographical locations from the very beginning.
Denton’s book deserves a serious reading by everyone involved in the debate over evolution. It is a new contribution to the discussion with a new perspective, not just a rehash of old arguments. What is surprising is that this book had to be published by the Discovery Institute. Denton is advocating a fully materialist account of evolution, drawing on a thread that has had many adherents for the past two centuries. He is, in many ways, no more radical than Stephen Jay Gould was, although Gould seemed to backtrack in later years. Denton also draws heavily on mainstream concepts of emergence and self-organization. It is a sad statement that the biological world has become so calcified in insisting on its single unchanging paradigm that this heavily empirical and materialist book could not be widely promoted by those who loved Gould, whose books this volume by Denton deserves to sit next to.
