Evolution Unscathed: A Review of Darwin Devolves


(S. Joshua Swamidass) #1


Evolution unscathed: Darwin Devolves argues on weak reasoning that unguided evolution is a destructive force, incapable of innovation

Authored by two of Behe’s colleagues at Lehigh University’s Department of Biological Sciences,

Academic buildings can be quirky places. Like proteins they evolve, adapting to new functions while holding on to traces of their past, occasionally performing tasks that are in conflict with one another. Iacocca Hall is no exception. Once home to the research and development division of Bethlehem Steel, the mountaintop building now houses Lehigh University’s Department of Biological Sciences. The most infamous (among scientists) and celebrated (among creationists) of our 22 faculty is Michael Behe, a well‐known proponent of intelligent design and a tenured member of our department who recently released his third book, Darwin Devolves: The New Science About DNA That Challenges Evolution (HarperOne, 2019, 352 pp.).

This is a phenomenal article. The best of the reviews that have come out, echoing, expanding, and adding too much of what the rest of us have said. Some greate quotes:

About Real Time Evolution

Proteins are promiscuous (Hammer et al. 2017). They moonlight, by chance interacting with other cellular components to effect phenotype outside their traditionally ascribed roles (Copley 2014). These adventitious functions can be strengthened by selection, allowing a protein to assume a new or a dual role. This topic was raised in a recent review of Darwin Devolves in Science (Lents et al. 2019), where the authors highlight a study that employed experimental evolution to strengthen the weak nascent ability of a protein in the histidine biosynthesis pathway to act on a similar substrate in tryptophan biosynthesis (Näsvall et al. 2012). For multifunctional proteins, gene duplication and divergence can parse specific functions into separate proteins, each now free to specialize to its own task (Hittinger and Carroll 2007).

About Misleading Metaphors

The planthopper’s hind legs are a “large, in‐your‐face, interacting gear system (p45).” As for the “supremely complex molecular machine called the spliceosome,” simple scissors will not do. Behe opts for “an automated machine that could make fancy paper cut‐out dolls (p61).” Most of the analogies in Darwin Devolves are not Behe’s creation—he has done well to scour press coverage (Yong 2013) and the scientific literature (Burrows and Sutton 2013; Franze et al. 2007) for relatable metaphors; and he is generous with their use. But reality remains: proteins are not machines, a flagellum is not an outboard motor, and no one is claiming that mousetraps evolved gradually by natural selection.

Behe nearly catches his own error. He notes: “Metaphors, of course, do not denote the thing they are applied to. They are vague analogies… [I]f metaphors are taken too seriously in science, they can be confusing at best; and they can often be actively misleading (p201).”

Much more to dig into here.

The most comprehensive review of Darwin Devolves yet
(S. Joshua Swamidass) #2

I would very much agree with this:

Largely funded by federal grants, scientists have a moral responsibility (if not a financial obligation) to ensure that the core concepts of our respective fields are communicated effectively and accurately to the public and to our trainees.


As an aside, and in the name of finding agreement, the review linked in the OP noted the following:


Citing sections I find important as I go:

If Behe is trying to claim that gene loss will result in all genes being lost, then good ol’ brewers yeast (whose hard work I will be enjoying this evening) demonstrates otherwise. Gene loss matches gene gain.

One aspect many of us have not focused on is the importance of regulatory elements in evolution.

Great example of proteins being IC in some populations but not in others. This demonstrates how IC systems evolve.

Example of an IC system evolving.

The reviewers had the same view of Behe’s definitions of IC and the presence of IC in the evolution of lambda phage.

All of these could be the start of a thread all on their own. The review article is what the military would call a “target rich environment”.

(S. Joshua Swamidass) #5

That is exactly right, and I have been planning to make this clear. By steps that each on their own are “devolution,” we can evolve irreducible complexity. We can “devolve” into irreducible complexity.

(Nathan H. Lents) #6

But please don’t keep using the words “devolve” and “devolution.” If these terms sneak into our language, this will only breed confusion and serve to undercut the hard work we’re doing to clarify evolutionary theory for the public.

(S. Joshua Swamidass) #7

Hence forth, the term “devolve” will be comfortably cushioned within quotes, as an indicator we are using an idiosyncratic term outside established science.

(Nathan H. Lents) #8

and in spoken form, air/finger quotes must be used each and every time. It is so ordered.


I think this is why so many Christians gravitate toward ID. These terms need to be defined. If random is defined as every outcome being equally likely, this is not true. Behe should use “external intelligence” rather then “unguided.”

When responded to, this review makes it sound like “Behe is wrong. Evolution IS purposeless and an atheistic process.” Off goes the Christian to ID.

What if they said “IC is produced through several natural processes without external intelligent input through changes that are highly constrained due to physics and chemistry.”

Sounds a lot less threatening to me than “random and unguided processes.”

I don’t want to go into a discussion of the definition of random, but…yeah. Behe AND the reviewers need to precisely define their terms.


In this case, mutations are random with respect to fitness. It’s a bit like the game of craps. Not all outcomes are equal. 2 and 12 are relatively rare while 7 is the most common outcome. The important part is that the dice aren’t influenced by the chips on the table. Putting your bet on a hard 8 doesn’t increase the probability of rolling a hard 8. The dice are blind to the chips. In the same way, the processes that cause mutations are blind to what the organism needs in a given environment, or at least they appear to be blind by all of the statistical tests that have been used.

This gets us to the other important bit. Science uses statistics to define randomness. Science doesn’t make any claims about God’s involvement, or more specifically, about God’s involvement in mutations. Could God be guiding everything from the roll of the dice to mutations in a way that we can’t perceive using our statistical tools? Sure, I guess so. However, science is silent on that topic.

What if they just said, “IC is produced through several natural processes”. I think that is all that needs to be said. At the same time, ID proponents seem to dislike the idea of natural processes being capable of producing what we see in biology. They seem to require supernatural input outside of the natural processes we observe.

The reviewers are going to be using the standard definition of random that I described above. I may have violated your wishes, but hopefully it can supply some insight into how scientists define randomness.

(S. Joshua Swamidass) #11

Please stop saying this. We discussed several times this is not precisely true :slight_smile:

Gauger: Answering Art Hunt on Real Time Evolution

There are very few, if any, concepts in biology that don’t have exceptions.