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Re: Archaeopteryx



In a message dated 6/16/03 1:18:33 AM EST, mightyodinn@yahoo.com writes:

<< Invalid argument. Because something happens in one lineage doesn't mean it 
MUST
 have happened in others. For example, just because no other vertebrates have
 rostral bones does not mean that ceratopsians could not have had them.
 At any rate, other types of homeotic shift have been observed. And it's been
 shown that digit identity and number are developmentally independent. >>

If a "frame-shift" can be shown to happen from time to time in other 
lineages, then you have a much stronger case for its occurrence in the 
dinosaur-avian 
lineage. If, however, a "frame-shift" is an artifactual construct dreamed up 
to account for an annoying discrepancy in a cladogram, unknown anywhere else, 
then it is just another junk hypothesis, something cladists dredge up to 
explain why their cladograms don't seem to accord with reality.