A Book Review from Books At a Glance
By Robert C. Newman
With the continuing advance of modern biological technology, the evidence that unguided evolution can account for all the diversity of living things is unraveling. With his third book in just over 20 years, Lehigh University biochemist Michael Behe continues the discussion he began with Darwin’s Black Box (1996) and The Edge of Evolution (2007). In this new book, entitled Darwin Devolves: The New Science About DNA That Challenges Evolution, the author discusses the problems that “blind watchmaker” evolution faces, the various theories that are being proposed to rescue Darwinian evolution, the data we can now get from the DNA, and a proposed solution.
A major theme of this book—which I have never before seen expressed—is that “Darwinian evolution proceeds mainly by damaging or breaking genes, which counterintuitively, sometimes helps survival. In other words, the mechanism is powerfully devolutionary. It promotes the rapid loss of genetic information. Laboratory experiments, field research, and theoretical studies all forcefully indicate that, as a result, random mutation and natural selection make evolution self-limiting. That is, the very same factors that promote diversity at the simplest levels of biology [also] actively prevent it at more complex [levels]. Darwin’s mechanism works chiefly by squandering genetic information for short-term gain” (37-38).
In this book of ten chapters and about 300 pages, the author begins with the problems facing Darwinian evolution. He reminds us that the theory pretends to knowledge that we do not have: namely, that its mechanism (random mutation and natural selection) is adequate to be able to generate the complexity, functionality and diversity that we see in present-day living things, all starting from one or a few initial life forms. Behe concedes that this Darwinian mechanism is capable of generating low levels of diversity, such as characterize the bottom levels of the biological classification scheme—the diversity found within genera and species. But since we are now able to unpack and study the DNA of living organisms, we can finally tell something of what is happening when mutation and natural selection do their work, thus testing the Darwinian mechanism.
For instance, the polar bear, closely related to the large brown bear, differs in ways that make it especially viable in the Arctic—its white coat, its greater resistance to cold weather, and its ability to handle the sorts of fatty foods available in such regions. But it now appears that the genetic changes that produced these variations seem to be “damaging … likely to degrade or destroy the functions of the protein that the gene codes for” (15-17). This will be a major theme of the book.
In chapter two, Behe reminds us of the “fathomless elegance” that we find again and again in living things. Among other examples, he mentions the interacting gear system which allows the planthopper to make phenomenal leaps hundreds of times longer than its body (44-47). He responds to the claim that the vertebrate eye is wired backwards (the wiring interfering with the light by being placed in front of the retina) by noting that some of the cells in front of the retina function as fiber-optic cables to channel light directly to the sensitive cells in the retina (48-50).
In chapter three, page 82, Behe gives a chart of the five major concepts of Darwin’s theory of evolution: (1) the nonconstancy of species; (2) the descent of all organisms from constant ancestors; (3) the gradualness of evolution; (4) the multiplication of species; and (5) natural selection. He next (83) labels these “Darwin’s middle theories” and suggests two more premises, which he calls “Darwin’s first and last theories.” Darwin’s first theory is “the utter randomness of variation” which is much more essential to his view than the five components listed above (84). Darwin’s last theory is “the truly audacious, profoundly nonintuitive, completely unsupported part of Darwinian theory … that such a process repeated over time would lead to coherent, integrated, sophisticated, seemingly purposeful systems such as the eye” (89).
Chapters four and five sketch a number of attempts that have been made to solve problems that are admitted by many evolutionists to face Darwinian evolution. But Behe notes that none of these explain how “any fundamentally blind mechanism can account for the elegance of life” (91).
Part Three (chapters six through nine) discusses the data that is now available to us as a result of the work that has been done in deciphering DNA. Looking at family lines in chapter 6, Behe notes:
Yet in order to stringently test Darwin’s crucial first theory (the completely unguided randomness of variation) and last theory (repeated rounds of mutation and selection somehow form coherent complex functional features), it is still not enough just to track changes in DNA and their effects on a few plants and animals. One also has to examine huge numbers of organisms over many generations—or at the very least to examine the straightforward effects of mutations in modern populations whose history is well known. Only in the past twenty years have such detailed, rigorous evolutionary studies even begun to be conducted (142).
Behe then goes on to examine “Darwin’s” finches of the Galapagos Islands (143ff) and the cichlid fishes of Africa (161ff). In some two million years of evolution of the former, these finches have diverged from their ancestor only at the level of genus and species (see his chart on page 154). A similar chart (page 164) is given for the cichlids of the African Great Lakes. Behe comments:
The huge number of brand-new cichlid species [about 500] in Lake Victoria has been widely hailed as the most spectacular example of evolution in (relatively) modern times and spoken of in breathless terms everywhere from popular articles, to student textbooks, to professional publications. Yet just as with Darwin’s finches, if classification categories were represented as the eight digits of a sum of money totaling hundreds of thousands of dollars, cichlid evolution in the African Great Lakes would be confined to the pennies and dimes columns on the right. Compared to the vast sweep of life, that’s just evolutionary change. Even the IRS tells taxpayers to round off the cents columns in their tax returns. If that were applied to evolutionary biology, all the touted variation of cichlids would be disregarded (164).
In chapter 7, titled “Poison-Pill Mutations,” Behe discusses “The Most Definitive Evolution Experiment Ever” (172ff). At Michigan State University, microbiologist Richard Lenski has been growing cultures of the common bacterium E. coli for over 25 years, studying their lineages for more than 65 thousand generations. For large animals, this would be equivalent to about a million years. And the experiments represent large numbers of organisms, too. Behe notes that recently, Lenski’s team has been able to study the results at the DNA level. He comments:
The bottom line is this. After fifty thousand generations of the most detailed, definitive evolution experiment ever conducted, after so much improvement of the growth rate that descendant cells leave revived ancestors in the dust, after relentless mutation and selection, it’s very likely that all of the identified beneficial mutations worked by degrading or outright breaking the respective ancestor genes. And the havoc wreaked by random mutation has been frozen in place by natural selection (179).
Later in the chapter, Behe mentions a study of people who are immune to type II diabetes. This beneficial situation apparently comes from a mutation that destroys a gene the pancreas uses. A similar result was found for people with a mutant gene that lowers cholesterol levels (192).
The large number and variety of dog breeds have been frequently mentioned as showing the power of selection, though in this case it is artificial, not natural, selection. But when the DNA is examined, these mutations are mainly those involving degrading various genes. Behe gives some details on pages 193-95.
Chapter 8 begins with this remark:
Even as it helps a species to adapt to its present environment in strict conformity with Darwin’s theory, random mutation is much more likely to damage genetic information than to build it. Over time that relentless tendency fences life in, making it less and less flexible. In retrospect, the easy production of new species and genera by widely diverse organisms—plants, insects, reptiles, fish, birds, as discussed in Chapter 6—coupled with the failure to generate any new higher classification categories [family, order, etc.] are exactly what we should have expected from a blind process that can trade genetic inheritance for short-term gain (199).
In a section called “The Blind Metaphor,” Behe notes:
The primary way by which natural selection makes evolution self-limiting is by promoting poison-pill mutations. Whatever genetic alterations that help an organism survive and reproduce better than its competitors will be fodder for natural selection—even if the alterations make a species less able to adapt in the future (200).
In hindsight, that is what we should have expected. Despite the boost in plausibility it receives from its metaphorical name, over multiple rounds natural selection is clearly nothing like the opposite of chance, no more than, say, gravity is the opposite of chance. Both of those phenomena are certainly directional, but only for one step …
The same for natural selection. It will favor the increase in the number of organisms that do better in their environment for any reason, regardless of the basis for the variation (203).
The upshot of all this is that changes requiring specific multiple mutations are badly out-performed by simple, destructive mutations that increase viability. As Behe points out:
When responding to David Snoke and myself, Michael Lynch wrote that, using the assumptions of his optimistic model, “adaptive multiresidue functions can evolve on time scales of a million years (or much less).” Okay, much less—let’s say a hundred thousand years. But as Richard Lenski’s experimental work (described in Chapter 7) shows so clearly, beneficial damaging mutations evolve on a time scale of weeks. That’s at least a million times faster than the simplest [mini-irreducible complexity] features evolving by the fastest route imagined (248).
In part four, entitled “The Solution,” Behe suggests (as you may already have guessed) all this points strongly to intelligent design. The features in the upper part of the biological classification scheme (kingdom, phylum, class, order, family) indicate that there is a Mind behind all this.
A distinguished book! If you are at all interested in the claims and evidence of evolution, this is a must read.
Robert C. Newman is Emeritus Professor of New Testament and Christian Evidences at Biblical (now Missio) Seminary, Director Emeritus of the Interdisciplinary Biblical Research Institute, and a Fellow of the American Scientific Affiliation.