This is the first of a series of posts reviewing Michael Denton’s new book Evolution: Still a Theory in Crisis.
The fossil record has always been a problem for Darwinism, as Darwin himself was the first to note. In Origin of Species he asserted that if his theory of gradual transformation of organisms through the accumulation of micro-adaptions over eons of time were true, “then the number of intermediate varieties, which have formerly existed, [must] be truly enormous.” And in the very same paragraph he admitted that: “Geology assuredly does not reveal any such finely graduated organic chain; and this, perhaps, is the most obvious and serious objection which can be urged against my theory.” Darwin tried to save his theory by suggesting the fault was not in his theory but in an extremely “imperfect record.” But he was candid enough to admit that, “[he] who rejects these views on the [imperfect] nature of the geological record, will rightly reject my whole theory. For he may ask in vain where are the numberless transitional links which must formerly have connected the closely allied or representative species . . .”
Here we are over 150 years later and as far as the fossil record goes, things have gotten no better for Darwinism.
“What is missing [in the record] are the many intermediate forms hypothesized by Darwin, and the continual divergence of major lineages into the morphospace between distinct adaptive types.” Robert L. Carroll, “Towards a New Evolutionary Synthesis,” Trends in Ecology and Evolution 15 (2000): 27
“I wish only to point out that [gradualism] was never ‘seen’ in the rocks.” Stephen Jay Gould, “Evolution’s Erratic Pace,” Natural History 86 (May 1977), 14
“Stasis is now abundantly well documented as the preeminent paleontological pattern in the evolutionary history of species.” Niles Eldredge, Reinventing Darwin: The Great Evolutionary Debate (New York: John Wiley, 1995), 77
Enter biochemist Michael Denton, who helped touch off the ID movement over 30 years ago with his seminal Evolution: A Theory in Crisis. Dr. Denton is perhaps uniquely qualified to speak to this issue. As a religious agnostic, he has no doubt that evolution occurred and that the process though which it occurred was entirely natural. Moreover, he is firmly convinced that the diversity of life can be accounted for based on “descent with modification” from a common ancestor.
So what sets Denton apart from your run of the mill materialist Darwinian such as Richard Dawkins? Just this: From the days of Darwin himself to this present moment, the Darwinist has said that if the fossil data do not conform to the theory, so much the worse for the data. In contrast to this approach, Denton subscribes to the crazy notion that one should try to conform his theory to the observations instead of the other way around. Denton’s approach has profound implications for evolutionary theory. At a fundamental level it means that a theory of evolution that synchs with the observations must account for the discontinuities that are all but ubiquitous in the fossil record, instead of always struggling to write such discontinuities off as an artifact of an imperfect record. In Evolution: Still a Theory in Crisis Denton sets out to do just that.
In his Introduction, Denton begins by defining two key schools of thought – structuralism and functionalism – that will be contrasted throughout the book.
According to the structuralist paradigm, a significant fraction of the order of life and of every organism is the result of basic internal constraints or causal factors arising out of the fundamental physical properties of biological systems and biomatter. In other words, these constraints do not arise as adaptations to satisfy particular functional ends . . . These internal constraints, or ‘laws of biological form’ as they were referred to in the 19th century, were believed by many biologists before Darwin to limit the way organisms are built to a few basic designs or Types, just as the laws of chemical form or crystal form limit chemicals and crystals to finite sets of lawful forms. This view implies that many of life’s basic forms arise in the same way as do other natural forms — ultimately from the self-organization of matter — and are genuine universals.
In contrast to structuralism Darwinists hold a “functionalist” view of evolution:
According to the opposing paradigm, often referred to as functionalism, the main fundamental organizing principle of biology is adaptation to serve various functional ends. On this view, the main type-defining homologs (pentadactyl limb, etc.) are not the result of physical law. Instead, functionalists see homologs as a result of adaptations built by cumulative selection during the course of evolution to meet particular environmental constraints. Adaptations built in this way are contingent in the sense that they are undetermined by natural law. . . . This is, of course, the currently prevailing and mainstream view. All Darwinists, and hence the great majority of evolutionary biologists, are functionalist by definition, as all evolution according to classical Darwinism comes about from cumulative selection to meet functional ends.
I found Denton’s reference to laws of biological form very interesting in light of my recent post entitled ID for Materialists. In that post I argued that materialists should stop running from the overwhelming teleology that even the most cursory glance at the data reveals and instead join the search for “natural telic laws” that Thomas Nagel described in Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False. And indeed Denton cites Nagel in his book.
In this regard, the first important thing I learned from Denton is that the idea of natural telic laws long predates Nagel. Denton notes that as early as 1866, Richard Owen, the father of Anglo-Saxon structuralism, argued that life on earth is the result of a lawful natural process. In his Anatomy of Vertebrates, Owen claimed that the path of evolution was “preordained . . . due to innate capacity or power of change, by which nomogenously-created [generated by law] protozoa have risen to the higher forms of plants and animals.”
This does not mean that structuralists believe Darwinism is completely wrong. They give Darwin his due. But they argue that Darwinian adaptations (such as the famous finch beak) are merely an “adaptive mask” on the basic Types. For example, all tetrapods exhibit the basic taxon-defining character of the pentadactyl limb (five fingers and five toes). This is one of the “Types” to which Denton referred in the above-quotation. Structuralists acknowledge, however, that the differences in the morphology of the pentadactyl limbs of the various tetrapod species likely came about through Darwiniam mechanisms.
This means that while the functionalist asserts that organisms are infinitely malleable and arose through a fundamentally stochastic and contingent process, structuralists assert that the development of organisms is constrained by natural telic laws. The Types arose spontaneously and abruptly as a result of the innate properties of biomatter acting in accordance with natural telic law, and only relatively minor adaptations of the Types can be attributed to Darwinian processes.
The structuralist view, of course, has the advantage of being consistent with the fossil record. That record does not show, as Darwin suggested, a finely graduated organic chain between major Types. Instead, it shows abrupt appearance of various Types followed by stasis. Again, using the pentadactyl limb as an example, Denton has no doubt that the limb evolved from the fins of fish. Yet the fossil record simply does not support the view that the evolution of the limb from the fin occurred gradually over eons of time. The fossil record is instead conspicuous for the absence of transitional forms from fish fin to pentadactyl limb. This means one of two things if a purely naturalist account of evolution is true: (1) all of the evidence for the gradual evolution from fish fin to pentadactyl limb has been swallowed up by time, and we have to take the Darwinian account on faith in the teeth of the evidence; or (2) the Darwinian (i.e., functionalist) account is false and something like the structuralist account is true.
There is, of course, a third alternative, and that is the Types arose as a result of the conscious choices of a designer. Interestingly, though Denton is considered a leading luminary of the ID movement, he never argues for that alternative. As I suggested in my recent post, certain forms of ID are compatible with a materialist paradigm IF there is such a thing as a “natural telic law.” Denton argues for this kind of ID, and as we shall see as we explore his book in future posts, he makes a powerful case.