Understanding Mutation Rates and Evolution
The Edge of Evolution
Evolution in Action and Michael Behe's Reaction
Mutations and Complex Adaptations
Blown Out of the Water
Joe Thornton vs Michael Behe
Irreducible Compexity
Defining Irreducible Complexity
Another Bad Review of The Edge of Evolution
19 comments :
Thanks for providing an easy reference for your postings on Behe's arguments. I'll put it up at my own blog, so I and others can find it faster.
By the way, Larry, it seems to me that your strongest argument (your other arguments are rather weak) against Behe's edge depends upon the work of Michael Lynch. Is Lynch's work beyond dispute?
Seems to me it's most of Behe's arguments that are rather weak, since they do in fact rest on a strawman version of evolution.
Everything could be shown false, otherwise it wouldn't be science. Does this fact render Lynch's work false, doubtful or ineffective?
Only in I-believe-in-magic-land are answers taken to be absolutely true and beyond dispute.
@ Bilbo - Lynches work on non-adaptive evolution is an important point, but not the only problem with Behe's thinking. Arlin Stoltzfus and Joe Thorton also have a lot to contribute in this.
But the main flaw as I see it is Behe's assertion that all AA's in a protein sequence are a defined string that must be perfect for function. He also extends this to say all protein-protein interactions must be perfect defines sequences. These assertions are simply not true. It is routine to knock out a gene (and therefore the protein) from one organism and replace it with that from another organism. This is even done to rescue yeast knockouts with human gene sequences. So other protein sequences also work.
His assertion that all mutations are harmful is incorrect. Many are nearly neutral (Ohta 1973. And because this part of the premise is incorrect, the whole argument falls.
Editing error in the middle...
"He also extends this to say all protein-protein interactions must be perfectly defined sequences.
Apology (?) accepted.
Bilbo says,
By the way, Larry, it seems to me that your strongest argument (your other arguments are rather weak) against Behe's edge depends upon the work of Michael Lynch.
Not true. The strongest argument against Behe is simply modern evolutionary theory and population genetics. That can be found in any evolutionary biology textbook.
Michael Lynch just happens to be one person who has described the flaws in Behe's argument in an effective manner.
Michale Lynch has also proposed that complex adaptive systems don't require natural selection. This is quite controversial and I doubt that most biologists would accept it. However, it's a viable scientific alternative to what Behe claims is impossible. Therefore, he is obliged to mention it if he intends to be taken seriously as a critical thinker.
Apology for what?
The Other Jim: "But the main flaw as I see it is Behe's assertion that all AA's in a protein sequence are a defined string that must be perfect for function. He also extends this to say all protein-protein interactions must be perfect defines sequences. "
I'm not aware of any place that Behe says that. Please give a reference.
Larry,
I understand you to be making two points: First, that most evolutionary biologists would say that the edge or limit on the number of mutations is much higher than the the six to eight mutations that Behe says is the maximum. Second, that Lynch has offered an hypothesis explaining how IC systems arose, and that Behe is at fault for not mentioning or addressing it. Is that correct?
It's covered here;
http://sandwalk.blogspot.de/2012/01/understanding-mutation-rates-and.html
First, that most evolutionary biologists would say that the edge or limit on the number of mutations is much higher than the the six to eight mutations that Behe says is the maximum.
Most evolutionary biologists would not agree with Behe when he says that when multiple mutations are required they all have to be beneficial and they all have to occur simultaneously.
Second, that Lynch has offered an hypothesis explaining how IC systems arose, and that Behe is at fault for not mentioning or addressing it.
That's mostly correct except that most evolutionary biologists don't accept Behe's definition of irreducibly complex. According to Behe's latest definition, an irreducible complex system is one that can't have evolved from scratch while still having the same function that the final system exhibits. In other words, an irreducible complex system is one that, by definition, can't have evolved. (Can you says "circular"?)
Apology for saying
Well, Larry, you have a blog on which you can "stand up and tell the audience that Behe is full of crap and lying about evolution." What's more you can take the time to explain in detail why you think that is the case. Why don't you? Or are you afraid that Behe would respond and make you look bad?
Regarding the first point, I'm unfamiliar with where Behe makes a requirement. Regarding the second, Behe's point is that IC systems are ones that don't evolve from simpler systems that have the same function. They can evolve indirectly from other systems, but the more complex the IC system, the less likely it is that they do so. It's in Darwin's Black Box, I think on pp.39-40.
Hi Other Jim (is OJ okay?),
I read the referenced post. Behe didn't make the claim you say he did, nor does Larry claim that he did. The question discussed was whether deleterious mutations can become fixed in a population.
I don't see where you have shown that Behe is lying about evolution in any of your postings.
You're just missing it. It is the claim that all nearly all aa substitutions are deleterious and quickly eliminated. They are not. Many variation of the protein sequence are possible which lead to a completely functional protein. Larry's extension to this point is to used nearly neutral theory of molecular evolution to explain how a lot of variation can persist in the population.
Maybe this post is more clear on the point...
http://www.pandasthumb.org/archives/2008/04/behe-versus-rib.html
Of course you don't.
They can evolve indirectly from other systems, but the more complex the IC system, the less likely it is that they do so.
Which simply means that this kind if "irreducible" complexity is evolvable, so IC is a misnomer.
Why "indirectly", by the way? What's indirect about change of function? There are no physical laws conserving function, so it's always free to change.
Post a Comment