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“Darwin Devolves” – Behe’s Rewriting of Evolution: A Critique from a Christian

Michale Behe’s latest book, Darwin Devolves, purports to demonstrate that a major challenge to evolution is that rather than producing new functions, the demonstrable changes that we can see in experimental science is due to “devolution” or loss-of-function in genes. Behe bases this, in part, on his “First Rule”: “The First Rule of Adaptive Evolution… Break or blunt any functional coded element whose loss would yield a net fitness gain” (185). (It’s stated somewhat differently on the first page of the book: “The First Rule of Adaptive Evolution: Break or blunt any functional gene whose loss would increase the number of a species offspring” – emphasis his.)

I am sympathetic to Behe’s project. As a Christian, I would prefer there to be testable, obvious proof that God exists, and Intelligent Design theory purports to be that for at least some kind of cosmic “intelligence.” On the flip side, I am also wary, because I recall Dietrich Bonhoeffer’s words that “a god who could be proved by us would be an idol” (DBWE 11, 260). I’m not convinced that God works in such a way as to leave tantalizing fingerprints all over everything for us to find. God is personal and we relate to God in a personal way, not in an abstract way that can remain impersonal or without challenge. For most of my life, I was a young earth creationist, and then spent several years studying apologetics and advocating ID theory. Since then, I’ve become much more skeptical of ID theories, and Behe’s book illustrates several of the reasons why.

Selection Effect

One of the biggest difficulties I have with Behe’s book here, as well as with ID in general, is that there is, of necessity, a selection effect happening in the examples used. That is, the human author making the argument must be selecting examples rather than showing the whole range of life and applying their theory to it (to do the latter would be prohibitively time-consuming and likely impossible). But because there is such human agency in selecting the examples, the tendency towards selecting those examples which most easily support one’s theory is at least possibly in play.

In Darwin Devolves, selections of which evidence is discussed appears to be a large part of the weight of the argument. Evidence is mustered from polar bears and the deleterious way they acquired (perhaps not the term Behe would use) “white” fur, from laboratory experiments with bacteria and fruit flies, and from the (in)famous Darwin’s Finches. In each case, it is shown (I believe demonstrated–though I admit I’m not an expert so it is possible that this is wrong) that the “evolution” of certain features (eg. different forms of beak, see p. 143ff) is not new information or beneficial mutations but rather mutations or deletions genetically that are acting on existing DNA in ways that Behe calls “devolutions” rather than evolution.

Though it seems contentious to change the terminology of genetic reshuffling/deleting on existing information to “devolution” when it seems most assuredly an example of evolution (if not, necessarily, fitting within Behe’s specific definition(s)–more on that below), assuming Behe is right here, it would be a fascinating argument if it carried the day. But Behe must demonstrate, for his argument to work and for evolution (again, his usage) to fail, that such deletions/reshuffling is the case in every single instance of purported evolution. That would be a monumental task (and likely impossible), but one way to approach it would be to broaden the selection of data and to take on some of the most powerful evidences of evolution. But here we see the selection of Behe appears to be quite artificial. In addition to the selection effect, Behe fails to note that the very thing he’s arguing shows the failure of evolution as a theory (loss-of-function, etc.) in a lab experiment for E. Coli are, in fact, an expected outcome for such a lab experiment, and the evidence for genuinely new information is dismissed.

Additionally, given Behe’s language about loss-of-function and his “first rule,” readers would be right to expect that the data would support loss-of-function as the predominant, if not the only, means by which scientists have been able to mention what they call evolution. But that is demonstrably not the case. Rice and Lang note:

In humans only ∼3.5% of exonic and splice site variants (57,137 out of 1,639,223) are putatively loss‐of‐function (Saleheen et al. 2017), and a survey of 42 yeast strains found that only 242 of the nearly 6000 genes contain putative loss‐of‐function variants (Bergström et al. 2014). 

Gregory Lang and Amber Rice ” Evolution unscathed: Darwin Devolves argues on weak reasoning that unguided evolution is a destructive force, incapable of innovation” https://onlinelibrary.wiley.com/doi/full/10.1111/evo.13710

Behe’s challenge to evolution doesn’t mention these and other related facts. The selection effect is operating strongly here, and it is selecting out those aspects of the data that do not match the theory.

Misrepresentations and Language

Throughout the book, there were difficulties with Behe’s use of terminology and misrepresentations of arguments. The definition of “evolution,” for example, seems malleable to fit Behe’s needs. He begins by noting that Darwin’s own theory couldn’t account for genetic data (Darwin didn’t know about it) and so had to be modified. But as more modifications to the theory happen, Behe seems to take that as evidence that evolution is, minimally, in crisis. Chapter 4 is dedicated to the various ways scientists have modified the theory of evolution, according to Behe–in order to “shoehorn” various discoveries into it. But one would hardly discredit the theory of gravity due to the fact that it has been modified to account for more modern discoveries. Would Behe use the same charged language that we have “shoehorned” in modern science to the theory of gravity in order to discred it? Doubtful.

Additionally, Behe is quick to dismiss evolution and evidence for it as useless or baseless. For example, across pages 22-24 he notes various examples that have been said to have evolved and then asserts that deleting the word “evolved” doesn’t change the information in the sentence. For example, “Birds like the silky flycatcher… that are mistletoe specialists have evolved a ‘wiggle dance.'” Behe then asserts that no information is lost if one just says the birds “have a wiggle dance.” But this seems to be clearly untrue, for the claim that the birds “evolved” a wiggle dance would include in it inherited traits, genes, and behaviors, where as merely “having” a dance does not. Even if one is anti-evolution, the claim that deleting the word “evolved” from sentences like that doesn’t delete information seems puzzling.

Behe is also keen to discredit natural selection. On 99-100 he offers an example that he alleges proves that increased DNA is not due to selection but rather entirely to the amorphous term called “luck.” But renaming selection “luck” doesn’t really undermine the fact that Behe doesn’t seem to have an answer for how DNA increases within his “First Rule” system. Indeed, across these pages, he actually attributes the formation of DNA increase to environmental factors and having the increased DNA continue due to isolation. But that is exactly what evolutionary theory suggests–when populations are isolated, there is the chance for selection to operate differently one one group than on another. Behe saying this is “serendipity” or “luck” seems clear obfuscation on his part–avoidance of the fact that it is exactly due to factors alleged by evolution to drive natural selection that has led to increase in DNA.

Perhaps the part of the book is Behe’s charge that evolution must produce entirely new lifeforms, including new phyla, given enough time. In looking at Darwin’s finches, he argues that the changes among them is incredibly tiny, given the amount of time they’ve had as an isolated population. he asserts that it is “very unlikely” that an environmental factor is limiting their evolution (155) and goes on to ask whether 2 million years in isolation is too little time for evolution to make major changes. After noting that “profoundly different animal phyla… arose during the Cambrian explosion… in only about ten million years” (ibid), along with some other swift evolution, he incredibly states: “Surely we should expect at least one crummy new phylum, class, or order to be conjured by Darwin’s vaunted mechanism in the time the finches have been on the Galapagos. But no, nothing” (ibid). Behe’s claim is, frankly, absurd. I don’t know of any evolutionary biologist who suggests that entirely new phyla are a necessary outcome of long-term isolation. Additionally, to compare the emergence of phyla during the Cambrian–before life had even begun to walk the land–to the state of the islands is disingenuous to the highest degree. Remarkably, Behe does nothing to acknowledge the extreme differences between the examples he cited and the state of the islands; instead, he writes, “A surprising but compelling conclusion is that Darwin’s mechanism has been wildly overrated–it is incapable of producing much biological change at all” (ibid). There is can be no doubt that this strong conclusion is in no way demonstrated by the fact that finches didn’t transform into new phyla, but Behe draws these kind of strong conclusions from minimal data throughout the book.

Conclusion

Darwin Devolves is tantalizing in theory, but in practice it does not prove what it sets out to prove. It would be nice, as the dust jacket states, to come to the point where “It’s time to acknowledge the conclusion that only an intelligent mind could have designed life.” But with all those weighted terms comes a burden of proof that is not met in the text. I have no doubt that an intelligent mind–God–brought forth life, but I remain unconvinced that God did so in a way that required direct intervention throughout the process.

Links

What options are there in the origins debate? – A Taxonomy of Christian Origins Positions– I clarify the breadth of options available for Christians who want to interact on various levels with models of origins. I think this post is extremely important because it gives readers a chance to see the various positions explained briefly.

What is the relationship between Christianity and science?- An Overview of 4 Views– How should the Christian faith interact with science? Do they interact at all? I survey 4 major views on these and other questions.

Be sure to check out the page for this site on Facebook and Twitter for discussion of posts, links to other pages of interest, random talk about theology/philosophy/apologetics/movies and more!

Origins Debate– Read a whole bunch more on different views within Christianity of the “origins debate.” Here I have posts on young and old earth creationism, intelligent design, theistic evolutionism, and more!

SDG.

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