Fwd: Re: Fwd: Re: Fwd: Re: rankless nomenclature

[Philip Cantino]

Tom Lammers wrote:

>
>No.  It is based on the fact that cladistics, while the best tool we
>have for making objective inferences about evolutionary history, is
>a far too weak and unreliable tool.  It generates testable
>hypotheses.  I have yet to be convinced that many of these
>hypotheses are a good approximation for the actual historic events
>they purport to represent.  If we want to use the method to
>classify, fine.  No problem.  Classifications are hypotheses; they
>come and go.  But names are another matter.  Names, in so far as
>practicable, should be stable.  The ICBN seeks this, the PhyloCode
>seeks this.  But because the PhyloCode is based on a method in which
>I have limited confidence, I believe the names it generates will
>prove to be less stable than those generated by the ICBN.
>
>I fling down the gauntlet: convince me that cladistics as a method
>for reconstructing phylogeny is of such great power and reliability
>that we should pin our system of names to it.  I concede that what
>you propose would be exactly the way to operate IF we were confident
>we knew the actual phylogeny.  But we don't and probably never will.
>Demonstrate to me that 9 out of 10 taxonomists who perform a
>cladistic analysis on a given set of organisms will get the same
>cladogram, irrespective of data utilized.  When that day comes, I
>will swear allegiance to the PhyloCode and toss out the big black
>book.
>

The PhyloCode does not require a complete and reliable phylogeny of
life.  What it does is provide a mechanism to give stable names to
those clades that we have enough confidence to name.  Sure there
is a lot of conflict between cladograms based on different data, but
there are also many clades about which there is no disagreement and
that we all accept. Shouldn't these clades have stable names?  Under
the current system, the names of even the best supported clades may
change because of arbitrary decisions regarding their rank.

I agree wholeheartedly with the perspective Rich Pyle has expressed
about the different functions served by rank-based and phylogenetic
nomenclature and the desirability of having both systems available to
serve the needs of different groups of people.  Although some
magazine articles about phylogenetic nomenclature have stressed its
replacement of the Linnaean system, this is not how I (or, I suspect,
most proponents of the PhyloCode) see it.  The question is not which
system one has "allegiance" to but which system serves one's needs
best in the context of a particular kind of research.  When I do
floristic studies of local natural areas (and a considerable amount
of my research time is spent on unpublished floristic studies of this
sort), I use traditional nomenclature--and probably will continue to
do so even after the PhyloCode is implemented. However, when I do
phylogenetic research, I want to be able to name well supported
clades without having to change the names of other clades or formally
name groups that I don't accept (i.e., groups that are monotypic,
paraphyletic, or whose monophyly is poorly supported).

Phil


Philip D. Cantino
Professor and Chair
Department of Environmental and Plant Biology
Ohio University
Athens, OH 45701-2979
U.S.A.

Phone: (740) 593-1128; 593-1126
Fax: (740) 593-1130
e-mail: cantino at ohio.edu