As I noted in my previous post, creationists have been working hard to spin the recent PNAS paper by Richard Lenski and coworkers on historical contigency in evolution.  And for good reason, as creationists are extremely fond of claiming that mutation cannot produce new, beneficial traits.  First up is intelligent design creationist Michael Behe, who wrote about the Lenski paper on his Amazon.com blog.

He writes:

I think the results fit a lot more easily into the viewpoint of The Edge of Evolution. One of the major points of the book was that if only one mutation is needed to confer some ability, then Darwinian evolution has little problem finding it. But if more than one is needed, the probability of getting all the right ones grows exponentially worse. “If two mutations have to occur before there is a net beneficial effect — if an intermediate state is harmful, or less fit than the starting state — then there is already a big evolutionary problem.” (4) And what if more than two are needed? The task quickly gets out of reach of random mutation. (…)

In The Edge of Evolution I had argued that the extreme rarity of the development of chloroquine resistance in malaria was likely the result of the need for several mutations to occur before the trait appeared. Even though the evolutionary literature contains discussions of multiple mutations (5), Darwinian reviewers drew back in horror, acted as if I had blasphemed, and argued desperately that a series of single beneficial mutations certainly could do the trick. Now here we have Richard Lenski affirming that the evolution of some pretty simple cellular features likely requires multiple mutations.

If the development of many of the features of the cell required multiple mutations during the course of evolution, then the cell is beyond Darwinian explanation. I show in The Edge of Evolution that it is very reasonable to conclude they did.

I’m severely puzzled by this.  Lenski showed that the emergence of the Cit+ phenotype almost certainly required at least three mutations:  One or more mutations to produce the appropriate potentiating genetic background, and then two more to arrive at Cit+.  The paper demonstrates the emergence of Cit+ from multiple mutations, yet Behe argues that such an occurrence is evolutionarily impossible.  He’s literally denying reality.  Not much you can say to that.

Next up we have the terminally ignorant Answers in Genesis.  As AiG is an organization that pushes the idea that the earth is only 6000 years old, their stuff is typically far more stupid than what comes out of the ID camp.  However, given that Michael Behe has simply stuck his head in the sand and said “nuh-uh”, the AiG response is actually more sophisticated (barely).  They begin by objecting that Lenski’s paper does not support “molecules to man” evolution.  Again, AiG seems to demand that every paper written about any aspect of evolution should demonstrate the evolution of human beings from the primordial soup.  This is asinine.  You want evidence for human evolution, read some paleoantropology papers.  Moving on, they say:

So what’s really going on in Lenski’s experiment? Actually, nobody really knows! Lenski’s team is still working to understand “just what that earlier change was, and how it made the . . . mutation possible.” They will likely be analyzing the genome of the original E. coli parent and the genomes of its “evolved” offspring. The citrate-processing ability may be due to the activation of a latent function or a beneficial (but not information-gaining) mutation that allows citrate processing.

Actually, the Cit+ phenotype is not likely to have arisen from a latent, “cryptic” gene.  Lenski writes in his paper:

This explanation seems unlikely to us because the Cit- phenotype is characteristic of the entire species, one that is very diverse and therefore very old.  We would expect a cryptic gene to be degraded beyond recovery after millions of years of disuse.

I’m also amused at their classification of a beneficial, Cit+ producing mutation as “not information-gaining”.  They admit that the exact nature of the mutations are unknown, so how can they claim no increase in information.  Furthermore, how are they defining “information”?  Creationists love to claim that evolution cannot increase genetic information, but they never explain precisely what they mean.  But in any case, their objection is absolutely wrong.  Then comes some good news:

Furthermore, creationists are just as interested in figuring out how the citrate-processing ability came about in this batch of E. coli. AiG’s Dr. Georgia Purdom is studying the research for an upcoming semi-technical article in the journal Answers In Depth.

Hurray!  More crap from Georgia Purdom.  I can’t wait.  Given how completely substance-free the responses to the Lenski paper have been so far, I’m counting on some quality pap from Dr. Purdom.

This entry was posted on Sunday, June 15th, 2008 at 11:47 am and is filed under Creationism, Liars for Jesus. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.