Re: [asa] Predictive Power: Astronomy vs. Evolution

From: David Campbell <pleuronaia@gmail.com>
Date: Sat Dec 09 2006 - 14:05:49 EST

> It seems to me that it's more complicated than this. When we look at the fossil
> record we rarely have genetic information to look at (I believe some TRex soft
> tissue was found not too long ago, Otherwise I could have said "never")

Although there are traces of soft tissue associated with the
occasional ancient fossil, the credible genetic information associated
with fossils is pretty much confined to cold and/or dry preserved
Pleistocene (Ice Age) material. I don't know of anything over 100,000
years that is universally accepted as genuine; amber sequences and the
reported dino sequence are contaminants. There is the possibility of
getting protein sequences from some older fossils.

> speciation in the fossil record could be
> occurring where little or no variation in physical characteristics occurs.

One example was detected using stable isotopic data in a planktonic
foram. The isotopic data showed an abrupt shift in habitat for part
of the life cycle, not accompanied by any evident morphological
change.

-- 
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 Sat Dec 9 14:06:01 2006

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