This is the fourth and final installment in my book review series on Darwin’s Doubt.
Part III: After Darwin, What?
In chapters 15 and 16, Meyer explores the various “post-Darwinian” models that have been proposed to account for the massive amount of biological information required to give rise to new body structures and ultimately, new body plans.
First, Meyer evaluates Dr. Stuart Kauffman’s theory of “self-organization,” the idea that new biological structures arise according to natural “laws of form” and then are preserved by the action of natural selection. Kauffman proposes that animal cells have certain self-ordering tendencies that serve to explain the emergence of new body plans (such as those that appear in the Cambrian) and the information for constructing them. This thesis fails, according to Meyer, because the chemical reactions thought to be responsible for the organizing of new forms lack the specificity necessary for orchestrating the precise arrangement of the billions (or trillions) of cells in an adult animal. Furthermore, Kauffman’s theory cannot explain the origin of the genetic regulatory networks he claims are needed for cell differentiation. Meyer explains, “…the self-organizational process that Kauffman cites cannot explain the origin of genetic information, because it derives from it.” Essentially, Kauffman’s theory presupposes quite a lot of preexisting (and unexplained) biological information. Meyer goes on to describe how Kauffman applies his ideas to the Cambrian problem. It is interesting to note here that Kauffman recognizes the top-down pattern in the fossil record as a true reflection of natural history, and his model accounts for this by proposing (highly implausible) “long-jump” mutations that lead to new body plans.
Stuart Newman’s theory of self-organization is briefly examined, but suffers the same problem: the need for preexisting genetic and epigenetic information. Meyer sums up the difficulty this way:
…advocates of self-organization fail to offer examples of either biological information or complex anatomical structures arising from physics and chemistry alone. They either point, as Newman and Kauffman do, to embryological development unfolding predictably as the result of preexisting information-rich gene products, cell membranes, and other cell structures. Or they offer examples of purely physical and chemical processes generating a kind of order that has little relevance to the features of living systems that most need explanation.
Meyer then turns to the three currently prominent non-Darwinian theories, beginning with so-called “evo-devo,” which proposes early developmental mutations that cause significant changes in an animal body plan. He points out that this model “contradicts the results of one hundred years of mutagenesis experiments,” which have shown how deleterious such developmental mutations actually are. “Neutral evolution” is the second model discussed. It suggests that over time, genomes expand as non-coding DNA and gene duplications accumulate, eventually producing positive adaptations on which natural selection can then operate. The problem with this model is that it doesn’t show that neutral processes can account for the enormous amount of genetic and epigenetic information actually required for new biological systems. Meyer goes into some detail on the weaknesses of neural evolution as a potential producer of new body plans. The third model, natural genetic engineering, as formulated by James Shapiro, says that mutations can be induced in a directed way by environmental signals. (This runs counter to the Darwinian idea of random mutations.) What’s missing, though, is an explanation for the informational programming that would be necessary for an organism to have the capability to respond to its environment in an appropriate, fitness-enhancing way.
That brings us to chapter 17, where Meyer proposes intelligent design (ID) as a viable explanation for the information problem inherent to the Cambrian event. Crucially, he explains and corrects the main misconceptions about ID theory. Specifically:
The theory of intelligent design does not reject “evolution” defined as “change over time” or even universal common ancestry, but it does dispute Darwin’s idea that the cause of major biological change and the appearance of design are wholly blind and undirected. Nor does the theory seek to insert into biology an extraneous religious concept. Intelligent design addresses a key scientific question that has long been part of evolutionary biology: Is design real or illusory?
Meyer explains the nature of abductive reasoning and how it is used to infer intelligent design when the artificial restriction to material processes is lifted. When ID is included among the multiple competing hypotheses, we can then ask whether or not there are indeed “Signs of Design in the Cambrian Explosion” (chapter 18). In this chapter, Meyer lists the criteria that must be met by any proposed cause of the Cambrian explosion and how intelligent design meets each one far better than any strictly materialist theory could.
So, the answer to the aforementioned question is a resounding YES: The Cambrian event exhibits strong indicators of design. At this juncture, I must offer my unrestrained praise for the eloquent, thorough, well-organized and compelling nature of Meyer’s argument. He deftly pulls together all the strands running through the book into a coherent case for ID. He exceeded my (already high) expectations for a strong, credible contribution to discussions of biological origins.
The final two chapters of the text deal with “The Rules of Science” and “What’s at Stake” in the case of materialism versus ID. These are valuable addenda to the overall argument being made in Darwin’s Doubt, as they explain the demarcation problem (the still unresolved question of what separates science from non-science) and the features of ID theory (predictive, testable, capable of problem-solving) that lend it scientific legitimacy. Furthermore, Meyer demonstrates that, ironically, “There is no specific (non-question-begging) demarcation criterion that succeeds in disqualifying the theory of intelligent design from consideration as a scientific theory without also doing the same to its materialistic rivals.”
Lest any critic accuse Meyer of using a “gaps” argument, he specifies that:
Advocates of intelligent design do not propose intelligent causes because they cannot think of a possible mechanistic explanation for the origin of form or information. They propose intelligetn design because they think it provides a better, more causally adequate explanation for these realities. Given what we know from experience about the origin of information, materialistic explanations are the deficient ones. (Emphasis, mine.)
The bottom line is, ID offers a positive case for design, not just criticism of materialistic theories.
Meyer ends the book with some lucid, candid commentary on the interaction of science and faith. I have a deep appreciation for his philosophy:
To gain a true picture of the world and our place in it we need facts–empirical data. But we also need perspective, sometimes called wisdom, the reference points that a coherent view of the world provides…The theory of intelligent design generates both excitement and loathing because, in addition to providing a compelling explanation of the scientific facts, it holds out the promise of help in integrating two things of supreme importance–science and faith–that have long been seen as at odds.
Well done, Dr. Meyer, well done.