Evolution is Still Not a Theory in Crisis, but Neo-Darwinism Might Be

Michael Denton, Evolution: Still a Theory in Crisis (Seattle: Discovery Institute Press, 2016).

This book is a update to Denton’s 1985 book of the same title (minus the word “still”), but it is an important departure from the earlier work.  

We are well aware that book reviewers bring their own biases and beliefs with them as they read. So, because we are convinced this is an important book that needs to be discussed fairly, we will start by owning up to our own worldviews related to the issues covered. We are adherents of Darwinian evolution, and we think that Charles Darwin’s insights underlie all of biological science. By this we mean acceptance of the principle of descent with modification of all life from a common ancestor, through the mechanisms of genetic variation and natural selection. We are also evolutionary creationists, and believe as a matter of faith that life ultimately derives from the divine Creator. We are unconvinced by arguments against Darwinian evolution, including those from young earth creationists and intelligent design advocates. Our worldview did not initially dispose us favorably to a book with this title written by a well-known proponent of ID and published by the Discovery Institute.

Denton describes his own worldview throughout the book as “structuralism”, which is all about the form that matter (including biological matter) takes. This contrasts with “functionalism” (the basis of Darwinism), which is about how things work, including adaptation. His hero is Richard Owen, a pre-Darwin naturalist who wrote extensively on the concept of natural law as the basis for biological forms. Denton takes the pre-Darwinian 19th-century concept of Types—clades, such as vertebrates and mammals—as his central theme. According to Denton (and Owen), Types are the manifestation of built-in biological laws; and what distinguishes them are structural homologs that cannot be explained by either slow, progressive steps (the gradualism of classical Darwinism) or purely adaptationist natural selection. This philosophical view fits well with the standard anti-evolution paradigm of Intelligent Design.

On almost every page, Denton claims that Darwinism is refuted, contradicted, or “stands on sand.” According to Denton, the key hallmarks of Darwinism are a strict adherence to adaptationist functionalism and an insistence on gradualism. Gradualism has long been a focal point of attacks on Darwinism by ID advocates, and is the basis for the irreducible complexity argument. 

But at this point, things get interesting, because Denton does not go there. He never mentions irreducible complexity in the entire book. His attack on what he calls Darwinism is presented almost entirely in the words and research of current evolutionary biologists. He devotes a whole chapter to Evo-Devo, and quotes Sean B. Carroll extensively. When he argues (using examples like vertebrate limbs, feathers, flowers, insect legs, or human language) that there is no evidence for stepwise selective mechanisms for major innovative changes that define clades, he quotes Gould, Koonin, A. and G. Wagner, and Pigliucci—not Johnson, Behe, or Dembski.

Denton agrees (as does everyone else) that natural selection is the best explanation for microevolution. Denton expands microevolution to a process that occurs in clades (such as mammals or even vertebrates). But, like the creationists, he argues that macroevolution is a different story and requires an entirely different mechanism to explain the jumps from fins to limbs, or scales to feathers.

And here is where we fully expected to see the phrase “evidence for design” fill in the blank of how such innovations come about, if not by Darwinian natural selection. But that is not what Denton says in this book. Not at all. In fact, the word “design” rarely occurs in the book, and never in the context of any kind of explanation for the origin of a biological form or mechanism. What Denton does say is this:

There is a tree of life. There is no doubt that all extant life forms are related, and descended from a primeval ancestral form at the base of the tree. (p. 112)

And this:

Descent with modification implies a pattern of descent through time, where extant forms have descended with modification from common ancestral forms, right back to the last common ancestor of all extant life. But the fact of descent with modification cannot be taken as…. support for any sort of gradualism. [emph. added] (p. 195)

And:

However, my claim that life is an integral part of nature is not an argument for design or a defense of Plato’s cosmology, but an ontological verdict on the fabric of reality…[emph. added] (p 281)

So is Michael Denton saying that evolution (which he calls descent with modification) has occurred from the start of life until the present, and that the complex and innovative structures that mark the major phylogenic branches of the tree of life took place by natural means rather than by special creation or intelligent design? Yes, that is what he is saying. So, you might be asking (as we were), why exactly is evolution “still a theory in crisis”? The answer is that the crisis is all about what so many evolutionary biologists have been saying: neo-Darwinism is not correct. Slow accumulation of random mutations in structural genes just doesn’t cut it when we are talking about innovative variations that give rise to new clades.

Gould said this with punctuated equilibrium. Kimura toppled the adaptationist exclusivity with the neutral theory. James Shapiro (who is strangely absent from the book) has been talking about the very same thing for years, as has Pigliucci, Wagner, Muller, Jablonka, Laland, Newman, and all the others of the Third Way and the Altenburg 16. Simon Conway Morris (another strange omission in Denton’s list of scientific allies) has turned evolutionary biology around with his demonstration of convergence and constraints on evolutionary possibilities.

So what Denton is proposing here is closer to the Extended Evolutionary Synthesis, which is struggling with neo-Darwinism to be the standard model for evolutionary biology, than to the vaguely crafted, creationist-flavored non-hypothesis of the original ID movement. Denton presents epigenetics, transposition, the emergence of new properties from complex precursors, and (we were happy to see) includes a strong emphasis on the role of gene regulatory networks in the production of innovative structural phenotypes. So, importantly, Denton is not appealing to a creative intelligence in lieu of biological mechanisms, but weighing—as many evolutionary biologists are also doing—the relative importance of natural selection as a driver of evolutionary change.

In this book we find what has been lacking in many ID arguments: the threads of a coherent scientific hypothesis to explain the great question of emergent novelties during evolutionary history. There is no mention of the impossibility of explaining complex and novel biological structures and systems by natural causes or the red herring of statistical improbability. In contrast, Denton constantly stresses that biology is based as much on natural law as is physics. His arguments against gradualism and panadaptationism are biological rather than metaphysical, and are very much in line with those of the Extended Synthesis.

While this is very welcome and we think a great step forward, we admit that the continuous trumpet call of “anti-Darwinism” in the book is grating and gratuitous, and (like the title) could limit the book’s contribution to conversations among Christians on the reality of evolution. Some of the rhetoric comes across as protesting too much. Origin of Species should not be treated as an inerrant text. Of course Darwin made errors, as did Newton, Einstein, and all real scientists in the past and present.

While Darwin did stress the importance of incremental gradual changes, and he did hold that natural selection should be invoked as an adaptationist explanation for all new features, these ideas are not so much errors as overstatements. If we define extreme-Darwinism as the dogma of Darwinian inerrancy, then we can substitute “extreme-Darwinism” for “Darwinism” in almost every instance of its use in Denton’s book. By that small “insertion mutation”, we almost render the entire book fully in line with one mainstream current of evolutionary biology.

Denton’s Evolution (the sequel) is an important book, because it might represent an intriguing and fascinating opportunity for real progress in the sometimes bitter debate about evolution among Christians. That might be an optimistic view, but we are not alone in this idea. Darrel Falk, past president of BioLogos, has written a review of the book for Amazon that reflects our own thoughts quite closely.

In his review, Darrel says:

…Denton’s work is highly embedded in the well-established fact of common descent of all living organisms… Hence if this work does become central to the future of the Intelligent Design Movement it would be great if they would focus in on a coherent theory like that which Denton espouses…

We can only agree that it would be great indeed. We think that Darrel’s enthusiasm stems from the same source as our own optimism that this book represents a potential for a real breakthrough in discussions between evolutionary creationists (EC) and the ID movement. There is nothing that forces EC to adhere to an extreme Darwinian or neo- Darwinian stance, and one of us (SG) has written about the new Extended Synthesis as being the best framework for EC to follow (Perspectives in Science and Christian Faith, in Press; God and Nature, In Press).

Denton’s new book may very well be a catalyst in the eventual reconciliation of two Christian scientific philosophies of the nature of life. If that does happen, we believe it will be a joyful day in Heaven, and we can only say: The Lord be praised!