Re: paraphyly (was: Not Monotremes again!)

[Stan Friesen <swf@ElSegundoCA.ATTGIS.COM>]

 From: jshields@iol.ie (James Shields)
 > >[The main argument between cladists and non-cladists is the validity
 > >of *para*phyletic taxa].
 > 
 > Could you explain this a little, please? I presume polyphyletic means "many
 > parents" or something like that, but I'm lost on paraphyletic.
 > 

monophyletic (sensu Hennig): containing the most recent common ancestor
        and *all* (I repeat *all*) descendents of that ancestor.
        (Peter Ashlock suggested calling this holophyletic, meaning
        "complete branch").

paraphyletic: containing the most recent common ancestor, but NOT
        all of its descendents (aka "partial branch").

polyphyletic: NOT containing the most recent common ancestor.
        (from "many branched").


An alternate definition of monophyletic that is now moribund used
to include both "holophyletic" and paraphyletic.

swf@elsegundoca.attgis.com              sarima@netcom.com

The peace of God be with you.