[Taxacom] Elimination of paraphyly: sensible or not?

Stephen Thorpe stephen_thorpe at yahoo.co.nz
Thu Feb 8 19:21:43 CST 2018


At any rate, the basic problem appears to be that "understanding" is always inconclusive and in flux (and may not even be able to be defined very precisely if you mean some sort of collective understanding by the entire scientific community). So, the question is how much inconclusivity and/or flux do we want in taxonomic classification? My preference is to try to minimise it. I would go for more wide scoped supraspecific taxa (genera, families, etc.) There is nothing worse than oversplitting of genera, etc. This just leads to more instability as a result of phylogenetic studies.

Stephen

--------------------------------------------
On Fri, 9/2/18, Michael A. Ivie <mivie at montana.edu> wrote:

 Subject: Re: [Taxacom] Elimination of paraphyly: sensible or not?
 To: "Stephen Thorpe" <stephen_thorpe at yahoo.co.nz>, taxacom at mailman.nhm.ku.edu
 Received: Friday, 9 February, 2018, 2:09 PM
 
 OK, I misunderstood you, but you
 misunderstood me as well.  "... in the 
 face of ever advancing understanding of the
 evolution of life on earth" 
 is not
 meant to be just phylogenetics, but all aspects of biology
 that 
 is bring more and more sense to the
 universe every day (expect in 
 understanding
 voting patterns or political motivations).
 
 Mike
 
 
 On 2/8/2018 6:02 PM, Stephen
 Thorpe wrote:
 > Mike said: "... in
 the face of ever advancing understanding of the evolution of
 life on earth"
 >
 > It is a moot point whether
 cladistics/phylogenetics does in fact advance understanding
 of the evolution of life on earth! It seems to me to be
 little more than a paint by numbers approach which can in
 theory be replicated by anyone else who uses the same
 character weightings, etc., but replicability alone does not
 imply that we are actually advancing understanding of the
 evolution of life on earth"!
 >
 > You also misunderstood my comments about
 retaining birds and mammals as named taxa. They ARE
 monophyletic, and I didn't say to necessarily retain
 them as taxa of equal rank to reptiles (so subtaxa of
 reptiles are indeed fine to me also), I just meant that we
 don't want to simply dump them into reptiles such that
 Reptilia simply contains various subtaxa from each in a way
 that doesn't group bird (or mammal) subtaxa together
 under a name.
 >
 >
 I'm surprised that anyone finds "interesting"
 the inconclusive and ephemeral results of phylogenetic
 studies!
 >
 >
 Stephen
 >
 >
 --------------------------------------------
 > On Fri, 9/2/18, Michael A. Ivie <mivie at montana.edu>
 wrote:
 >
 >   Subject:
 Re: [Taxacom] Elimination of paraphyly: sensible or not?
 >   To: taxacom at mailman.nhm.ku.edu
 >   Received: Friday, 9 February, 2018,
 12:56 PM
 >   
 >   Hi
 Stephan,
 >   
 >   It
 seems to me that you have this premise
 >   backwards.  Rather than there
 >   being a
 >   cabal
 of rabid cladists obsessed with eliminating paraphyly,
 >   I
 >   think there
 is a cabal of rabid
 >   revanchists
 obsessed with hanging on to
 >   familiar
 paraphyletic taxa in the face of ever
 > 
  advancing understanding
 >   of the
 evolution of
 >   life on earth.  In
 actual practice, most advocates
 >   of a
 monophyly standard continue to use and
 >   propose taxa that cannot be
 >   shown to be
 >  
 monophyletic, but if we have evidence, why not use it?
 >   
 >   You say
 "We wish to
 >   retain birds and
 also mammals as useful monophyletic
 >  
 taxa, for obvious reasons."  How, if you
 >   mean as
 >  
 nomenclaturally-recognized taxa at
 >   a
 level equal to reptiles, is this
 >  
 obvious,
 >   or to be wished for?  We
 have the words "birds"
 >   and
 "mammals"
 >   for the folk
 >   taxonomy, but why not recognize them
 for what they really
 >   
 >   are? Subtaxa of Reptiles works fine
 for
 >   me.
 >   
 >   As for why look for
 >   monophyletic lineages?  Because
 scientifically,
 >   doing phylogenetics
 is INTERESTING.  I myself
 >   do mostly
 alpha taxonomy,
 >   because I
 >   don't have the skill set to be a
 leading
 >   phylogeneticist, but
 >   I find their results
 >   to be very thought provoking,
 interesting and even
 >   exciting.  It
 is not that they get too much
 >  
 funding, it is that
 >   faunistics and
 taxonomy
 >   get to little.
 >   
 >   Mike
 >   
 >   
 >   
 >   On
 >   2/8/2018 3:07 PM, Stephen Thorpe
 wrote:
 >   >
 >  
 Hi all,
 >   > I have been giving some
 thought
 >   to the cladistic obsession
 of eliminating paraphyly in
 >  
 taxonomic classification. For many taxa (above species),
 the
 >   subtaxa consist of one or more
 clearly monophyletic groups,
 >   plus a
 possibly paraphyletic residue (i.e. no apomorphies to
 >   bind the residue together into a
 monophylum). So, if we must
 >  
 eliminate paraphyly (or possible paraphyly), the only
 >   options are to either: (1) subsume the
 monophyletic subtaxa
 >   into the
 paraphyletic residue; or (2) break up the
 >   paraphyletic residue into monophyletic
 subtaxa. Effectively
 >   the two options
 may actually be equivalent. An example might
 >   help to illustrate my point. Let's
 take a simplistic
 >   view of reptiles
 as scaly tetrapods, birds as feathery
 > 
  winged bipeds derived from reptiles, and mammals as
 hairy
 >   tetrapods derived from
 reptiles. So, amniotes (reptiles,
 >  
 birds and mammals) are a monophyletic group, as are birds
 >   and also mammals, but not reptiles
 (reptiles being the
 >  
 "paraphyletic residue"). We wish to retain
 birds
 >   and also mammals as useful
 monophyletic taxa, for obvious
 >  
 reasons. So, what to do? Luckily, within reptiles there
 are
 >   some monophyletic subgroups of
 sufficient diversity to be
 >   useful,
 but this might not have been the case if all
 >   reptiles were just basically
 "skinks", with only
 >  
 species or perhaps also generic differences between them.
 >   Had this been so, amniotes would have
 to be taxonomically
 >   split between
 numerous (maybe hundreds) virtually identical
 >   taxa of "skinks", plus birds
 and also mammals as
 >   just two taxa at
 the same level (not necessarily a ranked
 >   level, but direct child taxa of
 amniotes). Would this be a
 >   useful
 classification of amniotes? I suggest that it would
 >   be far more useful to recognise a
 single paraphyletic taxon
 >   of
 reptiles (all the "skinks" in the hypothetical
 >   example), plus birds and also mammals
 (i.e. just 3 direct
 >   child taxa of
 amniotes). I wonder for plants, fungi and also
 >   invertebrates, if there might be many
 taxa analogous to the
 >   above
 hypothetical example, with a paraphyletic residue
 >   consisting of hundreds of
 "skinks", but also with
 >  
 just one or two very distinct and diverse monophyletic
 >   subtaxa? If so, would it be sensible to
 eliminate paraphyly
 >   or best just to
 live with a known paraphyletic residue as a
 >   unified subtaxon? Given the amount of
 limited resources
 >   which are being
 allocated to projects to eliminate
 >  
 paraphyly, to the detriment of alpha taxonomy, it would
 be
 >   nice to think that there was a
 clearly good reason for the
 >  
 elimination of paraphyly, but I'm not so sure that
 there
 >   is! The usual argument seems
 to be that you cannot make
 >  
 meaningful predictions from paraphyletic taxa, but how
 much
 >   biology does rely on the making
 of predictions based on
 >   taxon
 membership, and what proportion of those predictions
 >   end up being true anyway? For example,
 you might predict
 >   that a newly
 discovered braconid is a parasitoid, but a few
 >   braconids are phytophagous anyway. So,
 I guess that the main
 >   question that
 I am posing is whether we think that the
 >   benefits of monophyly justify the
 spending of so much
 >   limited
 resources on the elimination of paraphyly? Perhaps
 >   the elimination of paraphyly is being
 driven instead by
 >   economic factors,
 doing phylogenies being a more cost
 >  
 efficient way for institutional scientists to spend their
 >   time on than alpha taxonomy?
 >   >
 >   Stephen
 >   >
 >  
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 >   >
 Nurturing Nuance
 >   while Assaulting
 Ambiguity for 31 Some Years, 1987-2018.
 >   
 >   --
 >  
 __________________________________________________
 >   
 >   Michael A.
 Ivie, Ph.D.,
 >   F.R.E.S.
 >   
 >   NOTE: two
 >   addresses with different Zip Codes
 depending on carriers
 >   
 >   US Post Office Address:
 >   Montana Entomology Collection
 >   Marsh Labs, Room 50
 >   PO Box
 >  
 173145
 >   Montana State University
 >   Bozeman, MT 59717
 >   USA
 >   
 >   UPS, FedEx, DHL Address:
 >   Montana Entomology Collection
 >   Marsh Labs, Room 50
 >   1911 West
 >  
 Lincoln Street
 >   Montana State
 University
 >   Bozeman, MT 59718
 >   USA
 >   
 >   
 >   (406)
 >   994-4610 (voice)
 > 
  (406) 994-6029 (FAX)
 >   mivie at montana.edu
 >   
 >   
 >  
 _______________________________________________
 >   Taxacom Mailing List
 >   Taxacom at mailman.nhm.ku.edu,
 >   http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
 >   The Taxacom Archive back to 1992 may
 be
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 >   
 >   Send Taxacom
 mailing list
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 >   To subscribe or unsubscribe via the
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 >   You can reach the person managing the
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 >   
 >   Nurturing
 Nuance while
 >   Assaulting Ambiguity
 for 31 Some Years, 1987-2018.
 >   
 > .
 >
 
 -- 
 __________________________________________________
 
 Michael A. Ivie, Ph.D.,
 F.R.E.S.
 
 NOTE: two
 addresses with different Zip Codes depending on carriers
 
 US Post Office Address:
 Montana Entomology Collection
 Marsh Labs, Room 50
 PO Box
 173145
 Montana State University
 Bozeman, MT 59717
 USA
 
 UPS, FedEx, DHL Address:
 Montana Entomology Collection
 Marsh Labs, Room 50
 1911 West
 Lincoln Street
 Montana State University
 Bozeman, MT 59718
 USA
 
 
 (406)
 994-4610 (voice)
 (406) 994-6029 (FAX)
 mivie at montana.edu
 
 


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