Re: [asa] flagella

From: David Campbell <pleuronaia@gmail.com>
Date: Wed May 23 2007 - 11:47:56 EDT

> And whether there is a single ur-gene really doesn't say anything about
> irreducible complexity one way or the other, does it? I never understood
> Behe to be saying that multiple genes were poofed into existence.

The duplication and modification of existing genes to create an
"irreducible" system poses two problems for the claim of
irreducibility. First, it provides a mechanism whereby the system can
be built. Secondly, it implies that an ancestral form got along just
fine without the full system in place.

An example sometimes invoked in ID is the system of DNA translation.
It uses a set of tRNAs (among other parts). However, some of the tRNA
genes seem to derive ultimately from a common ancestral gene. This
implies that something ancetral to all known modern organisms had a
simpler system with fewer tRNAs (and correspondingly fewer types of
amino acids).

-- 
Dr. David Campbell
425 Scientific Collections
University of Alabama
"I think of my happy condition, surrounded by acres of clams"
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Received on Wed May 23 11:48:30 2007

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