5 Kingdoms

[Ken Kinman]

Yes Bill,
     Your discomfort with Kingdom Protista is shared by many, for the strict
cladists have been very successful in making us feel guilty if we dare
recognize the naturalness and utility of paraphyletic groups.  Everyone
should read the book by Mayr and Ashlock where they discuss paraphyletic
groups.
      I have gone even further.  In my classification of Kingdom Protista, I
placed a marker {{Metaphyta}} after Phylum Chlorophyta, and a marker
{{Metazoa}} after Phylum Choanozoa.  I also place the marker {{Metaphyta}}
at class level (after Charophycea), and at ordinal level (as sister group to
Order Coleochaetales).   Placing these markers for "exgroups" to show their
cladistic placement transforms paraphyletic groups (e.g., protists,
prokaryotes, reptiles) into what I call semi-paraphyletic groups
(nomenclatorially paraphyletic, but informationally holophyletic).  Although
this is just one part of the Kinman System, this simple cross-referencing
technique should make even the strict cladists less antagonistic toward
paraphyetlic groups, and the rest of us can feel less guilty about
recognizing the utility of such taxa.
     The 30-year war between cladists and traditional eclecticists has gone
on far too long, and a fertile middle ground needs to be explored.  That was
the reason I developed the Kinman System.  The philosopher of science, David
Hull, no longer needs to be pessimistic that "no methods have been set out
thus far which permit the inclusion of both sorts of information [genealogy
and divergence] in a single classification in such a way that both are
retrievable" (Hull 1979; "The Limits of Cladism", Syst. Zool., 28:437).
Such methods do now exist, if only the cladists and eclecticists would stop
fighting long enough to realize that their bickering has become both
pointless and counter-productive.
                   ------Ken Kinman
P.S.  With all due respect to Lynn Margulis, I always found the term
Protoctista unnecessary.  I see no major problem with the continued use of
Protista, and we have more important things to worry about than this.

>From: Bill Shear <BILLS at HSC.EDU>
>Reply-To: Bill Shear <BILLS at HSC.EDU>
>To: TAXACOM at USOBI.ORG
>Subject: Re: 5 Kingdoms
>Date: Tue, 14 Sep 1999 09:41:15 -0400
>
>I've always been bothered by the "Kingdom" Protoctista (or Protista, pace
>Margulis).  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.  For example, if
>animals evolved from choanoflagellates and we consider Animalia a Kingdom,
>that makes both Protoctista and Mastigophora (if there is such a group now)
>paraphyletic.
>
>If we recognize Fungi, Plantae and Animalia, then Protoctista has to be
>broken up into gosh knows how many kingdoms.
>
>Personally, I think that we should stop at phyla--there are few enough so
>that one can be familiar with all, or almost all of them.  So long as we
>insist on shoehorning all phyla into just 5 kingdoms, the category has no
>practical use.
>
>Bill Shear
>Department of Biology
>Hampden-Sydney College
>Hampden-Sydney VA 23943
>(804)223-6172
>FAX (804)223-6374
>email<bills at hsc.edu

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