Re: [asa] How big a deal is homology?

I think creationists tend to think of macroevolution as being big changes -- e.g. dinosaur to bird. But macroevolution is any evolutionary change that creates two populations that can't interbreed and have fertile offspring, so macroevolution could be virtually undetectable from the phenotype. However, if some members of the two populations become separated and microevolution takes place in both to better make use of their environments, then you could see significant differences.
 
Bill Hamilton
William E. Hamilton, Jr., Ph.D.
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"...If God is for us, who is against us?" Rom 8:31

----- Original Message ----
From: Brent Foster <bdffoster@charter.net>
To: AmericanScientificAffiliation <asa@calvin.edu>
Sent: Tuesday, March 27, 2007 5:08:51 PM
Subject: Re: [asa] How big a deal is homology?

Yes that was my point actually. I accept the argument that a common designer would use common designs. But I was thinking more along the lines of your examples Terry. We know that DNA sequences can be inherrited. And genetic markers are used to establish identity, family lines etc. I don't think too many YECs had a problem with the DNA evidence against O.J. If the same genetic markers are used to establish phylogenetic relationships between related species, I don't see how one can except one and not the other. To bring in the Micro- vs. Macro-evolution contrast, there seems to be a continuum between family groupings, racial groupings, species groupings, genus groupings etc. The divisions between them are arbitrary. If one accepts micro-evolution, then how does a micro-evolving population know when to stop evolving so it doesn't cross the arbitrary line into macro-evolution?

Brent

---- "Terry M. Gray" <grayt@lamar.colostate.edu> wrote:

=============
Brent,

How big of a deal is homology in paternity testing? Or DNA
fingerprinting? Or establishing the human family tree? Or the dog
family tree?

What is the explanation for homology if it's not common descent? Why
isn't it 100%? Why does the degree of homology seem to be less as the
putative evolutionary divergence increases?

I will grant that using homology to detect evolutionary relationships
presupposes common ancestry (just as it does in paternity testing,
DNA fingerprinting, pedigree analysis (and manuscript transmission)).
But the mechanisms of transmission and change of genetic material are
known. It's not unreasonable (unless you have some philosophical or
theological or other reason not to accept it). However, the trees
generated by analysis of homologies are not presupposed and the
results are remarkably consistent with an evolutionary interpretation.

If evolution didn't happen, then God went through a lot of effort to
make it look like it did.

TG

 
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Received on Wed Mar 28 08:39:15 2007