[Taxacom] Pteridophyta

[Kenneth Kinman]

Hi Jim,
      Phylogenetically the taxon Phylum Pteridophyta is indeed not a
single clade, but to call it "meaningless" just because it is
paraphyletic is frankly just another case of strictly cladistic hogwash
and propaganda.  You call people wrong to consider Pteridophyta a good
taxon in which to express their interest.  But those "heaps of people"
would consider you equally wrong in criticizing them for studying a
paraphyletic taxon just because it happens to exclude that taxon's
spermatophyte descendants.         
       Consider the fact that before spermatophytes evolved,
pteridophytes were the only tracheophytes in existence.  In other words,
pteridophytes were a clade before one of them happened to give rise to
spermatophytes.  Therefore it is hardly a meaningless taxon.  It is
really no different than criticizing people who specialize in studying
reptiles just because Reptilia happens to be paraphyletic.
        --------Ken Kinman
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Jim Croft wrote:  
There are heaps of people around the world who profess an interest in
'pteridophytes', even 'Pteridophyta'.  Even though based on compelling
evidence, it seems to be phylogenetically quite meaningless, dare I say
'wrong', to do so.  But, as a concept it is meaningful to them in their
context.