PZ points out, and the expert agrees, this new paper from PNAS on the evolutionary underpinnings of the bacterial flagellum is a dog.

So, what's the problem? Lots of papers appear in the literature of dubious quality, why should this one be so worrisome?

Well, because it happens to be on the topic of the evolution denialists' favorite example of a "irreducibly complex" biological machine. Now, Matzke, the expert here, has written extensively on why the irreducible complexity argument is absurd, generally and specifically. He also has proposed a model for evolution of the bacterial flagellum.

And it has already occurred with the DI (Behe specifically) quoting Matzke out of context to imply that all understanding of the bacterial flagellum from an evolutionary perspective is somehow flawed.

The PNAS paper reaches conclusions that other workers find very questionable. Nicholas Matzke of the pro-Darwinian National Center for Science Education and Panda's Thumb blog declares the work to be of "canine quality", that is, "a dog." (2) (Although a geographer by training, Matzke has acquired some skills in the area and earlier published his own sequence comparisons of flagellar proteins in Nature Reviews Microbiology.) The bottom line is that Matzke is quite skeptical that the two dozen kinds of proteins in the flagellum core could be derived from a single protein. His point is well taken. Yet neither of the scientists that Science magazine journalist Jennifer Cutraro called for comments expressed any curiosity concerning that startling claim. (3)

Well, Matzke's writings on this are more than adequate to provide an evolutionary explanation for the origin of the flagellum. Notice how Behe also drags out the tired and debunked mousetrap analogy. Not only is argument from analogy an irrelevant contribution to scientific discussion, the analogy isn't even apt. As it has been pointed out again and again, the component parts of a mousetrap are individually useful, and the correct evolutionary analogy (that also applies to the flagellum) is that it could be composed of parts that were already in use in the cell, and simply recombined in a new way. But this is again a distraction. Note how they selectively use Matzke's pre-emptive criticism of a bad paper and the bad paper itself to generate an argument that would seem to cast doubt on an evolutionary mechanism?

This is the problem with science, we are self-correcting our literature, but the literature never goes away, and a denialist selectively quoting Matzke's criticism, this dog of a paper, and ignoring all the other writing on the topic can make it appear we know nothing about the evolution of this mechanism.

So, I give this latest argument a 3/5 on the denialism index. Behe being a bogus expert on anything, the terrible mousetrap analogy serving for our logical fallacy, and the blatant cherry-picking to misrepresent Matzke's writings serves the selectivity category.

By the way, I was sitting in the bar talking to Peter Griesar (who does great work with the One Campaign) about the blog, and he came up with a great suggestion. A visual depiction of each of the criteria of denialism. For instance, for conspiracy theories we would have to have a little gif of a tinfoil hat like this.

For selectivity a cherry would do nicely (for cherry-picking).

For false experts I really want a picture of a chimp in a white coat or maybe a puppet with strings attached. For now this creative commons chimp "thinker" will have to do.


For impossible expectations/moving goalposts, well, goalposts.


And finally for logical fallacy I was thinking a picture of a old-timey robot waving it's arms with sparks flying out of its head (does not compute). This is what I did quickly.


This argument from Behe would therefore garner the following honors.

Labels: Evolution denialism, Michael Behe