Ban the fungi imperfecti.......

Jeremy Hayter jhayter.niab.hr at GTNET.GOV.UK
Mon Feb 5 09:35:01 EST 1996


>Does anyone else feel that the existence of the so-called
>Deuteromycetes is unscientific and many times redundant?
I should think that most of us do, at least occasionally!

>After all, these fungi all have (or have had) sexual states
>and so should be placed where they properly belong to best
>demonstrate their phylogenetic relationship to other fungi.
>I'm at a loss to understand what their placement in a grab-bag
>class teaches us, other than their sexual states are rarely
>observed.
The taxonomic rules say that both perfect and imperfect states may be
treated as species but that the perfect binomial name may be used for either
the perfect or imperfect stage.  The name of the perfect form also takes
precedence.  In theory therefore, it is not that the sexual stages are
rarely observed, but rather that either i) sexual stages do not exist, ii)
sexual stages have never been observed or iii) sexual stages have been
found, but they have not yet been linked with the asexual stages of the same
fungus.

>Big Deal! If the caterpillar state of a certain
>butterfly is rarely observed, we don't place the butterfly
>in a different classification. 
But we might if there was a butterfly that did not have any caterpillars, or
even one that did not have to have caterpillars.

>Help me out here, I'm not
>trying to start a flame-war with the deutero-people, just
>trying to understand why such an unscientific classification
>continues to persist. Can't we just run an analysis on their
>ribosomal DNA and place them where they belong?
This would be OK if the results were unambiguous.  It would certainly be
interesting, but would probably just give us another reference framework in
addition to the taxonomic one.  If we were subsequently able to associate a
perfect stage with an asexual one we would end up having to rename/move the
fungus again.  Eventually we should be able to determine the relationships
between these fungi and "perfect" forms, but I suspect that this will be a
long process whatever methods we use, particularly as more
strains/isolates/species are likely to be discovered whilst we are still
struggling with those that we already know about!

Best wishes
Jeremy


(Dr) Jeremy (Hayter)
Department of Statistics and Information Technology,
National Institute of Agricultural Botany,
Huntingdon Road,
Cambridge
CB3 0LE
tel (01223) 342227 (direct)
fax (01223) 277602




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