[Taxacom] APG taxa

Kenneth Kinman kennethkinman at webtv.net
Sat Sep 3 21:48:49 CDT 2011


Hi Philip, 
        Actually embracting the molecular results for
the most part is probably a very good idea for angiosperms. Especially
since there are also newly discovered morphological data to back up much

of it. So I find the APG system very useful, although I still find a few

of their Orders excessively lumped (Poales, Malpighiales, etc.), perhaps

so much so that they are inadvertently creating some paraphyetlic taxa
which they purport to find "unnatural" and so bloated that they are not
particularly useful either. In other words, some of their lumping
overshot the mark and created more problems than it solved in the long
run. From their perspective (that paraphyly must be eliminated), they
will thus have to backtrack in the future (which will create some
additional instability).     
         But what has bothered me most about the APG
classifications is a lack of formal supraordinal taxa (especially
classes and subclasses), opting instead for informal clade names like
"core eudicots", "rosids", "asterids", "monocots", etc., and lots of
unassigned taxa floating in limbo. Easy way to side-step the paraphyly
problem at supraordinal levels, but it really just kicks the can down
the road (and their successors will be the ones who finally have to
admit that some paraphyly in natural classifications is inevitable). 
        Anyway, when it comes to supraordinal taxa for
angiosperms, I very highly recommend three Classes: (1) Magnoliopsida
(paraphyletic; ancestral to monocots and eudicots), (2) Liliopsida
(monocots), and (3) Rosopsida (eudicots).  It is a clearcut and stable
classification that will almost certainly stand the test of time.  The
only problem is that strict cladists will continue to attack it for a
certain period of time because Magnoliopsida is paraphyletic.  But
strict cladism cannot "kick the can" down the road forever, and
clade-only classifications ("cladifications") will increasingly be seen
as destabilizing in the long run.          
       The oversplitting or overlumping to avoid paraphyly cannot
continue indefinitely, and eventually more and more taxonomists will
finally realize that strict cladism was an illusion (much like the
illusion that housing prices in the USA would continue to rise forever,
until reality finally slapped them in the face in 2008).  So if you want

a stable classification of angiosperms at Class and Subclass level, a
few paraphyletic taxa are inevitable.  The same is no doubt true of a
few of APG's most bloated Orders, but it might take even longer for that

realization to set in at that level.  So, APG classifications are an
excellent guide, but they really need to be modified here and there to
eliminate the long-term effects of strict cladism (which still maintains

that paraphyly can be completely eliminated from natural
classifications).    
        -------------Ken Kinman
-----------------------------------------------------------     

Philip Jenkins wrote: 
            I know that Our Herb has switched to

the APGIII order of things, right or worng. We had the confinence that
APG's order might be close, if not exactly, the arrangement. We thught
it close enough that we believed no huge exceptions occur in the future
. No huge shuffles, in practilicality. We may be wrong or OK, to some
degree that we kind of believe that the molecular botanists are on some
kind of lasting trail. But who knows?            
    
         We have embraced the molecular results, yet we
may be terribly wrong. We arranged our collection to a place that is a
combinaton of Molecular Thought , and added to it our own instincts
about Botanical order. In reality. our system may or may not be correct.

We have embraced it in our own preceptions. We believe that the old
bunch ought to be not monophyletic. Our new order embraces the last
version of APG III. Are we correct in doing so, who the hell knows. 






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