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Re: Genetics and Morphology Collide



In a message dated 96-02-12 12:32:07 EST, you write:

>>Let me get this straight:  apomorphies are observations--the physical 
>>characteristics we think we see.  They are used to construct cladograms.  
>>The cladogram branches at certain points, and the characters possessed in 
>>common by the members of a branch are called synapomorphies--still an 
>>observation.  
>
>This is right on. Technically, an apomorphy is simply a derived character or
>character state.
>
>>But wouldn't it be an _interpretation_ that the observed synapomorphies 
>>have phylogenetic significance?
>
>Naturally. Other observers, with different cladograms, would arrive at
>different lists of synapomorphies. Making an apomorphy a synapomorphy places
>a phyletic interpretation on the character that is based on one's analysis.
>When lots of observers come up with more or less the same lists of
>synapomorphies via different analyses, then, maybe, we can speak with some
>assurance about the _real_ synapomorphies in the phylogeny.
>
>
>

It would then seem to me, IMHO, that the designation of an apomorphy is too
subjective to be of real use if an apomorphy to one is a plesiomorphy to
another etc. The thought comes to mind of creating a code of "Apomorphic
States" . Of course there would have to be gobs of conferences and a
concesnus would have to be worked out for each and every bone type and the
character states for them. Otherwise to have so many cladograms strewn about
the literary landscape would seem to diminish the significance of cladistic
theory as applied to fossil taxa.    

Regards,
Thomas R. Lipka
Paleontological/Geological Studies