Message 2001-02-0045: concerns

Fri, 09 Feb 2001 20:49:36 -0800

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Date: Fri, 09 Feb 2001 20:49:36 -0800
From: (Michael S. Y. Lee)
Subject: concerns

John wrote:

>I hate to be a pessimist, but I observe very little to no discussion of the
>groups for which no to few phylogenies are available.  How will the Pcode be
>applied to the many groups of organisms which are not represented by
>phylogenies?  Insects come to mind.  Many tropical plants at the subfamilial
>level come to mind.  I hear plenty of arguments for application of the Pcode
>with regard to vertebrates and perhaps even higher levels in the plant
>world, but how in the hell can we expect to apply a Pcode classification and
>nomenclature to understudied and very diverse groups?  What do we have to
>start with but the current system of classification and nomenclature?  In my
>opinion and the opinion of a growing number of folks, I think the answer is:
>NOTHING but the current systems.

>Don't we have a great deal of basic biodiversity survey work to do before we
>can just drop the current system and convert to a new system?  

Since, for once, a message arrives  while I'm in the office, I think I
should respond...

While poorly known groups might pose a problem for PhyloCode, if you stop
and think about it, they pose an even greater problem for current codes. 
For instance, under the current codes, one can't name a species unless one
already knows its relationships, since one must assign it to a genus (which
is usually now construed to be a small clade of species).  However, under
PhyloCode, the name of a species (e.g. a uninomial) is uncoupled from
information about its relationships - so one can name a species even if one
has no idea of its precise affinities.  Note, however, that phylocode has
some potential mechanisms (e.g. clade addresses) to convey informatin about
a species relationships, that are NOT part of its official name.

Higher Taxa:

I don't think it is true that current codes can name higher taxa accurately
in the absence of information of phylogenetic relationships.  If people
agree that 'Linnaean" higher taxa such as families, genera, etc., must be
monophyletic, then one still needs information about phylogenetic
relationships to accurately assign species to higher taxa (Linnaean or
otherwise).   For instance, putting a group of beetle species in the same
"family" would require some evidence that they are all more closely related
to each other than to beetles in other "families" - if such evidence is
available, one should be able to erect a proper node, stem, or apomorphy
based definition for that clade.
         Of course, the current system doesn't explicitly state that higher
taxa must be monophyletic, so one can avoid the need for phylogenetic
knowledge by arbitrarily erecting higher taxa using vague notions of
similarity instead of monophyly, but few scientists would advocate such
sloppy stop-gap measures.
        Finally, while the taxonomic imperative (as the current lack of
knowledge of biodiversity is called) is intimidating, I and many others are
optimistic of rapid improvement; just look at the results they are getting
with deep green (plants)...



Dr. Michael Lee
Department of Zoology and Entomology
The University of Queensland
Brisbane  QLD 4072

Ph.  61-7-3365-8817 (Direct Line)
        61-7-3365-2491 (Dept. Office)
        61-7-3392-4519 (Home - but it better be important)
Fax 61-7-3365-1655


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