kinman at HOTMAIL.COM
Thu Sep 16 06:32:32 CDT 1999
>Bill Shear wrote:
> > I've always been bothered by the "Kingdom" Protoctista
> > It seems clear that the three multicellular kingdoms arose from
>protoctistan ancestors, so some protoctist phyla are more closely related
>to multicell organisms than to other protoctistans.
> > If we recognize Fungi, Plantae and Animalia, then Protoctista has to be
>broken up into gosh knows how many kingdoms.
>Fred Schueler responded:
>* what one might call 'extreme paraphyly.' The only solution would seem to
>be to recognize kingdoms as in some sense ecological/trophic
>classifications, but that would formally re-introduce the idea of phenetic
>difference, and who knows what consequences might flow from that...
I am wondering if you would consider the four kingdom system to be
"extreme" paraphyly as well. Having Metazoa and Metaphyta arising from
Protista would be no more paraphyletic than mammals and birds arising from
reptiles. I don't use this kind of double paraphyly very often, but a few
eclecticists don't like anything beyond single paraphyly (and of course,
strict cladists don't like any at all).
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