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Re: ABSRD BAND on Sinornithosaurus feathers



In a message dated 3/20/01 11:47:30 AM, Dinogeorge@aol.com writes:

<< << Point mutations is what I think you are referring to here. >>
<Yes, that's what they're called. > >>

But I'm still not buying into it. The origin of feathers definitely did not 
involve just point mutations. There are too many new genes involved. New 
genes come from larger mutations such as gene duplication and divergence. 
That distinction is the one I am focussing on when I say that sulfur 
excretion would never have led to feathers. The ability of the kidney to take 
over by point mutations of the sort you are invoking is thousands of times 
more likely than the wholesale chromosome rearrangements involved in gene 
duplication.
   The concept that feathers evolved as sulfur excreters involves a heck of a 
lot more evolution to happen. Why wouldn't relatively quick-and-easy point 
mutations of the already-sulfur-excreting kidney be overwhelmingly more 
likely? Then, once sulfur is handled (easily, by an organ meant to handle it) 
the selective pressure to evolve an entirely new sulfur excretion system is 
not there.
  I think this discussion hinges on the notion that the protobird diet put a 
significant load on the sulfur-processing machinery of the body. But, from a 
medical biochemist's point of view (mine that is) the notion seems ABSRD. 
Sorry, pun intended. Organisms have incredible adaptability to dietary 
changes already built into them. Eating is, after all, THE most fundamental 
biological process.

Thomas P. Hopp
Author of DINOSAUR WARS, a science fiction novel published by iUniverse
Now Humans are the Endangered Species!  http://members.aol.com/dinosaurwars