I was asked today for a comment about a paper regarding irreducible complexity – Eliminating the Requirement of an Essential Gene Product in an Already Very Small Virus: Scaffolding Protein B-free øX174, B-free by Min Chen, Asako Uchiyama, and Bentley A. Fane, 2007.
I noted that despite this having been written in 2007, no one at all seemed to comment on it one way or the other. So, here is my short commentary on their criticism of Behe’s Irreducible Complexity. It is late, so I didn’t spend a lot of time reading in-depth, so please correct me where I am wrong.
In short the criticism Chen et al offers of Irreducible Complexity is that, for a specific bacterial virus, it has two structural proteins, B and D. D is sensitive to mutations, but B works even if heavily mutated. However, the lack of B is devastating to the organism. Chen et al therefore declare this system is irreducibly complex. They then are able to evolve a system which lacks B. Doing this, they claim, shows that the irreducibly complex system is evolvable, contra Behe.
So, first, I should point out that they never cite Behe for Irreducible Complexity. This seems to border on academic misconduct. The entire point of their experiment, according to the abstract, is to show that such a system is evolvable. Therefore, to not cite Behe is a pretty pathetic indicator of how the academy is handling their own business. Anyway, on to the actual critique:
- This is a much smaller system than the ones Behe used. Behe’s definition was for multiple interacting genes. In this case there are only two. If you think about it from the perspective of what Behe was getting at, the purpose behind “multiple” was that the difficulty increases exponentially if the intermediate results are unselectable. By using only a two-gene system, this is one of the few points where an exponential and a polynomial are of the same relative difficulty.
- Behe’s definition was based on proteins that *interact* with each other. In this case, as they are structural genes, there is little interaction between them. This is important, because interaction is what causes a system to behave chaotically in transitions between functional states.
- The experiment showed how to remove a gene, not how to create one. Behe is not arguing against the idea of organisms reducing genetic information, but of their gaining it.
- The individual steps were not selectable. That is, the experimenters did the selection, not nature. In fact, they pointed out that the wild-type outcompeted it when it was reintroduced. Thus, this proves Behe’s point, that the organism would have to pass through unselectable steps to achieve the goal. These steps were indeed unselectable if it were not for the experimenter’s designs.
- There was no study as to how the mutations were generated. I.e., they did not rule out any organismal teleonomy (either by the host or the virus) that might have helped the organism out. Behe’s IC, as I mentioned earlier, is only against random mutation, not teleonomic mutations. The experimenters did not test to see what the causal factors were in the mutations.
- Additionally, and I may be reading this incorrectly, but it seems that B was not actually absolutely necessary for function, only for function in certain conditions (i.e. based on certain temperatures).
- Also, and, again, I may be reading this wrong, but it seems that the experimenters actually reconstructed the gene, because the overlapping nature of the gene made the deletions that they wanted to make catastrophic. So, therefore, the experimenters actually created the gene for the purpose of having it evolve!
Due to the presence of genomic overlapping reading frames, constructing the deletions directly in the genome would have disrupted three gene products. Hence, the cloned gene approach was taken.
Anyway, if anyone has anything else to add or comment, please do so. I just wanted to make sure that there was a place on the web that had a discussion about this paper should other people want to know more.
It is interesting that Behe wrote Darwin’s Black Box before the explosion of gene sequencing that happened in the 2000’s. Nonetheless, as we can see by this example, even with genetic sequencing exploding by exponential levels, biologists have the hardest time even providing the simplest system to contradict his case.
But the thing that is not allowed to be said is that Behe might be correct. In fact, they couldn’t even bring themselves to be professional enough to even cite his work that they were trying to criticize.