Reviewing Behe's "Darwin Devolves"

[swamidass (S. Joshua Swamidass)]

The Question of T-urf13

So, back in August, @Art pointed out the formation of a novel complex protein, T-urf13 (On the evolution of Irreducible Complexity).

@Art

The caution is exploring whether this small protein improved or hurt the organism. I appears that it hurt the organism and had a detrimental impact on fitness.

IMO this totally avoids the obvious fact that a complex fully functional, gated ion channel formed by essentially shuffling the maize mitochondrial genome. By any measure, this is an increase in what an ID advocate would call functional information.

But as far as the biology, there are a few things to consider. One is that Turf13 is a gated ion channel, they key to which is a toxin produced by a fungus. From the perspective of the fungus, it is very beneficial.

But there is more to consider. Recall that plants have many ways to,approach the matter of sexual reproduction. Some plants (Cannabis) are monoecious - individuals may be male or female. Others are diecious - their flowers are both male and female. Diecious plants may tend to outcross or self-pollinate. Some plants incorporate male sterility into the mix, as a way to further promote outcrossing. (Of course in such populations there will be normal and male sterile individuals.)

Turf13 makes maize plants male sterile. Contrary to what some may claim, this actually increases the reproductive strategies for the plant, and is not a detriment to the plant. Also, male sterility is not an arcane and contrived creation of plant breeders. It happens in the wild as well. Put it all together, then what we have here is an increase, not only in functional information when it comes to proteins, but in reproductive options and interactions with microbes.

All coming about by piecing together some non-coding sequences. Randomly, via unguided processes.

The IC Argument is a Strawman Argument

This was also in response to my explanation of how IC has been an inconsistent and ultimately incoherent argument: Which Irreducible Complexity?. I won’t reproduce it here, but the summary is that Behe relies on a strawman in this argument, and also shifts his argument.

A Response from Behe Requested

A ID supporter here forwarded this on to Behe…

@colewd

I will start with your first comment on irreducibly complexity. I have looked at what you have and emailed my understanding to Mike and expect a response in the next couple of days.

@swamidass

I will look forward to hearing from Behe. He is a nice guy, and I have no ill will to him. Remember also that @art had been wanting him to engage on T-urf13 too, which appears to be a very complex enzyme arising out of non-coding DNA.

Behe’s Response on The IC Strawman

This the responses we got from him.

@colewd

Mike got back to me on both cases. Regarding irreducible complexity he agrees that the definition that I lifted from your reference from Bio Logos is correct.

He said to me he is not attempting to prove a negative “so evolution cannot work” is not his claim. Quoting him:

One should never say “can’t” in science because, as you observe, that’s equivalent to having to prove a negative. Rather, it’s better to say that we see plenty of problems for a Darwinian pathway, no reason why a Darwinian process would work, and no evidence that it does.

He also said he is going to expand his claims of IC in his next book that I think is due in February of next year.

Behe’s Response on T-Urf13

@colewd

@colewd why is he arguing against a Darwinian pathway when we think non-Darwinian pathways are important too?

This argument is 23 years old and it sounds like he is soon to update it. Regarding Hunts paper he read Rhodes et al 1995 and Mackenzie et all 1994 confirming @Art’s claim that a new gene can be created by genetic recombination of existing genetic information. Here is his direct response.

Hi, Bill. Well, I read the Rhoads et al 1995 review describing the system. I will make a few points:

— No Darwinian evolution of the supposedly new gene was shown. It was only discovered in that strain of maize.

— The ability of a random sequence of DNA to form a 4-helix bundle when transcribed beggars belief. It would not be expected to happen in many, many tries. That alone makes it seem very likely that the sequence was not random.

— The authors of the review write: “Although novel when discovered, it is now apparent that many other CMS genes have arisen by recombinational events involving other mitochondrial-encoded genes. In fact, mitochondrial DNA rearrangements are a significant force in changing the genome organization and in causing mutations in the mitochondrial genomes of higher plants (Mackenzie et al., 1994).” A distinct possibility implied by this, it seems to me, is that plant mitochondrial DNA is in fact built to provide easily accessible functional variability. In other words, intelligently provided, pre-existing information was tapped for this protein.

@Art and @Swamidass’s Response

To which @Art responded (Behe and Hunt: Irreducible Complexity and Numerology - #16 by Argon),

@Art

As you said, Bill, Behe grants that T-urf13 is pretty remarkable.

— The authors of the review write: “Although novel when discovered, it is now apparent that many other CMS genes have arisen by recombinational events involving other mitochondrial-encoded genes. In fact, mitochondrial DNA rearrangements are a significant force in changing the genome organization and in causing mutations in the mitochondrial genomes of higher plants (Mackenzie et al., 1994).” A distinct possibility implied by this, it seems to me, is that plant mitochondrial DNA is in fact built to provide easily accessible functional variability. In other words, intelligently provided, pre-existing information was tapped for this protein.

Doesn’t this sound sort of circular? Anyways, how would one determine this, without assuming the conclusion Behe wishes to draw?

Hopefully, Behe can take a bit more time and offer some more commentary about my essay.

And I wrote…

@swamidass

Raises a really interesting point. Consider @colewd’s falsification study…

colewd:

If a flagellum was produced in the lab with lots of bacterial replication and knockout of the DNA repair mechanisms then his claim is toast if you can show a mutational path to the functional flagellum.

Let’s imagine this happened. I’m pretty sure Behe would respond the same way…

colewd:

— The ability of a random sequence of DNA to form a [flagellum] when transcribed beggars belief. It would not be expected to happen in many, many tries. That alone makes it seem very likely that the sequence was not random.

After all, why not just suppose that God directly reached into the experiment to make a flagellum? Why suppose that the non-coding DNA was designed to evolve into a flagellum?

It seems that the argument is merely from incredulity, based on a strong assumption that complex proteins can’t evolve. If they do, it “beggars belief.” Honestly, it really seems to beg the question instead.