Fungi and Four Kingdoms

[Elizabeth Frieders]

Dear all:
I am a fungal phylogeneticist, and it has been difficult to read messages
about the taxonomic and phylogenetic position of fungi written by
non-mycologists. We don't tell you where to put insects and fish and higher
plants. Please don't tell us where Fungi ought to be placed. (And yes, many
mycologist actually still use Kingdom Fungi, and somehow manage to never get
confused about its usage and distinction from "fungi". -- It's really not
that foreign of a concept. "Animals" used to include all non-photosynthetic
motile organisms while "Plants" used to include all photosynthetic ones plus
bacteria and fungi. Scientists have not dropped or emended these terms as
the definitions were restricted.)

>>From: Curtis Clark <jcclark at CSUPOMONA.EDU>
> Microsporidia are intracellular parasites without
>>mitochondria. 18s rDNA put them on a long branch at the base of the
>>Eukaryotes, and their lack of mitochondria seemed to confirm that. I heard
>>a talk at IBC, though, that placed them on the basis of other genes firmly
>>in the Fung... uh, sorry, Eumycota. Thus making an unemended Protista
>>*poly*phyletic.

What is left out here is the fact that in this particular talk,
Microsporidia was on a very long branch, and not highly supported,
suggesting that perhaps it really does not belong within the Fungi. And that
there were several other talks given, using other gene sequences, in which
Microsporidia clearly did not fall within the Fungi, but elsewhere within
the Protista.

And whether or not Fungi is placed within the Protista will not change the
fact that Protista, as currently defined, *IS* polyphyletic. Whittaker new
it when he created the group. But it served a purpose at the time, namely
"things that don't fit in the other 4 kingdoms".

> Curtis,
>     That's great news.  Another reason for returning Eumycota to the
> Protista (emending it back to its pre- Whitaker-Margulis status.   That's
> what I love about the 4 Kingdom system.  It's so stable and useful.
>                      ----Ken Kinman

I do not understand the desire to take away the Kingdom status of Fungi.
Yes, they have roots in members of the polyphyletic Protista, but so do
Plantae and Animalia. All recent evidence (molecular, biochemical, and
morphological) place Fungi as the sister taxon to Animalia (+
choanoflagellates). So if Fungi should be relegated back to Protista, why
not Animalia or Plantae?  Or why not include Fungi as members of the
Animalia? They certainly would be better placed there than with Plantae, or
Protista.

And I do not understand why the 4 Kingdom system is more stable or useful
than the 5 (or 12 or 50). Yes, it is simple, but not useful in terms of
reflecting natural groupings. And it is only stable because some refuse to
quit using it. The 2 Kingdom system was useful and stable too, until it was
changed. Maybe we should just go back to that, merely because it is so
simple.

Recently someone posted that Linnaean ranks have served their purpose for
250+ years so why get rid of them. I think the recent discussions on numbers
of kingdoms, and the position and rank of this or that group scream the
answer. BECAUSE they have been used for 250+ years, it is time to reevaluate
their effectiveness in reflecting the phylogeny of life. There are VERY FEW
concepts in biology that have rmained in use for this long without change.
The foundation of biology is that it does change as new evidence is brought
forward. The new evidence is here. Let's do something about it rather than
clinging to ancient, creationist-based views of the classification of life
on earth.

Sorry if I have stepped on toes, but I am not alone in my views. Things
change, and biologists ought to be the first to realize that.
Beth Frieders
Assistant Professor
Department of Biology
University of Wisconsin-Platteville
Platteville, WI  53818