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Fwd: Progress in evolution



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Forwarded message:
Subj:    Re: Progress in evolution
Date:    95-10-27 12:01:30 EDT
>From:    Dinogeorge
To:      Moody@mail.oucom.ohiou.edu

In a message dated 95-10-27 11:20:53 EDT, you write:

>The english equivalent to a plesiomorphic character state is ANCESTRAL 
>character state.   There should be little confusion using this term unlike 
>using names like primitive or beginning or generalized or original.
>
>

I'm looking for something a bit more specific than a plesiomorphy: the state
of a character at or just after its initial appearance in a clade. For
example, say Archosauria is diagnosed by the antorbital fenestra.
Plesiomorphically (or ancestrally), the character is absent. Derived
apomophically, the character is wide open (and even later, secondarily
reduced or closed in some lineages). But primitively apomorphically, the
character is (probably) a narrow slit between the lacrimal and the maxilla.