kinman at HOTMAIL.COM
Sun Mar 18 22:25:23 CST 2001
I'm afraid I do have a big problem with "Animalia". It is an archaic
and confusing term which I do not use. Kingdom Metazoa is precise and
hopefully noone would mistakenly include Giardia or Parmecium as metazoans.
The same goes for "Plantae", and I see little advantage in using it when
Kingdom Metaphyta is unambiguous.
Kingdom Protista is a paraphyletic (but natural group) which includes
all eukaryotes except for Metazoa and Metaphyta (and Eumycota if you want to
recognize it as a fourth eukaryotic kingdom). Strict cladists may try to
characterise Protista as a polyphyletic "wastebasket", but it is
paraphyletic and just as real as the holophyletic Kingdoms Metazoa and
Metaphyta that it gave rise to. Where we make major cuts in the tree of
life may be somewhat arbitrary, but the paraphyletic and holophyletic groups
created by such cuts are real nevertheless (assuming the tree you are
cutting is accurate).
As for Order Dictyosteliida, they may appear to be quite different
from other mycetozoans, but the primitive Order Protosteliida probably gave
rise independently to Order Dictyosteliida and the orders that make up
Subclass "Myxogastrea" (Stemonitida, Echinosteliida, Trichiida, Liceida, and
Physarida). However all these mycetozoan orders apparently form a good
clade (see Spiegel, in Handbook of Protoctista, 1990)----BTW, that is
another name I dislike--- Protoctista strikes many people as unnecessary
Ivory Tower snobbery, and I see no reason to abandon the term Protista.
I was rechecking my notes and the cellular slime molds arose
independently in at least four different lineages. Besides Dictyosteliida
and Acrasida, there are also the Copromyxids (Class Lobosea) and Fonticulids
(Class Filosea). Cellular slime molds are all superficially similar as
aggregative amoebae, but this is simply convergence.
Contrary to popular belief, protistology has made great strides in
sorting through much of the confusing homoplasy and discovering more
fundamental and reliable synapomorphies. On the other hand, Bacteriology
and Zoology have some very serious misconceptions to work through in the
years to come.
Time for bed, Ken Kinman
>From: Curtis Clark <jcclark at csupomona.edu>
>To: Ken Kinman <kinman at HOTMAIL.COM>, TAXACOM at USOBI.ORG
>Subject: Re: saprophytes/molds
>Date: Sun, 18 Mar 2001 16:30:36 -0800
>At 03:44 PM 3/18/01, Ken Kinman wrote:
>> Likewise, the vernacular "fungi" can be used, but "Fungi" as a taxon
>>causes too many problems (and always has).
>And yet we have no problem with "Animalia", despite the fact that some
>people would include Paramecium and Giardia in it.
>>P.S. Order Dictyosteliida (filopodian cellular slime molds) are still
>>considered part of Mycetozoa.
>Then I guess I misunderstand what you mean; Physarum and Dictyostelium are
>not that similar.
>Curtis Clark http://www.csupomona.edu/~jcclark/
>Biological Sciences Department Voice: (909) 869-4062
>California State Polytechnic University FAX: (909) 869-4078
>Pomona CA 91768-4032 USA jcclark at csupomona.edu
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