Autapomorphy

[Vernie Sagun]

Dear Taxacomers,
I would like to ask about the term "autapomorphy", as I
understand this is a character state present in a taxon that
is not present in other taxa and is therefore
phylogenetically uniformative.  Autapomorphies are very
useful in creating keys and not useful in resolving
phylogeny.  But I have heard other views that say this is a
relative term, that clades could have a character state that
is "autapomorphic" for that clade, in the case of broader
(highly speciose or in ordinal level) phylogenies.  I believe
this is a misuse of the term since that "autapomorphic"
character state for that clade, is more appropriate to be
called a "synapomorphy".  The term autapomorphy can never be
realtive.  Can you help me clarify this?

Many thanks,
Vernie Sagun

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VERNIE G. SAGUN
Center for Biodiversity
Illinois Natural History Survey
607 E. Peabody Dr.,
Champaign, IL 61820-6970
U.S.A.
Tel: (217)244 9220
Fax: (217)244 0729
email: sagun at uiuc.edu
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