Fwd: Re: Fwd: Re: rankless nomenclature

[Philip Cantino]

Dick Jensen asked:

>I know this must be covered in PhyloCode, but I have not read the code
>carefully.  If there is no link between names and ranks, then how does one
>know, when one sees a clade name, what its position is in the
>hierarchy?  If the example provided in the paper by Pleijel
>(1999. Syst. Biol. 48: 755-789) reflects the way things might work,
>then I find it especially cumbersome: in his example, a terminal taxon,
>which may or may not be a "species," is referred to simply as
>Flexuous.  To identify the clades that Flexuous belongs to, the name is
>written as Flexuous (Ophiodromus, Hesionidae), the clades being more
>inclusive left to write.  So, if I follow his convention correctly, his
>taxon Lyonsi must be written as Lyonsi (Crassichaetae, Heteropodarke,
>Ophiodromus, Hesionidae).  There is nothing here to signify rank; the
>spellings are apparantly retained simply by priority.
>
>Is the above example an accurate view of the way the PhyloCode would or
>should work?

The position of a clade within the hierarchy is indicated, as Pleijel
has done, by citing the more inclusive clades to which it belongs.
This is analogous to the current practice of citing a family and
sometimes also an infrafamilial taxon to indicate the position of a genus.
In phylogenetic nomenclature, as in the current system, citing the
names of more inclusive taxa is optional, and the format is not
dictated by the PhyloCode.  Some people prefer to use slashes rather
than parentheses--e.g., Lamiales/Lamiaceae/Nepetoideae/Glechoma.  To
cite so many clade names is indeed cumbersome, but it is also not
required.  It will be done only when this information is critical and
then probably only once in a particular paper.  In most cases, I
suspect that only one reasonably familiar larger clade will be cited
to give readers a general idea where a particular taxon
belongs--e.g., Lamiaceae/Glechoma.  There is very little difference
between phylogenetic and traditional nomenclature in this regard, at
least with respect to clade names.  Species names are a different
story of course, since information about relationship is an integral
part of the name under the Linnaean system but will not be under the
PhyloCode.

Although it is not what Dick is asking about, I should point out
that in rejecting the species category, Pleijel differs radically
from most other PhyloCode proponents.  Unfortunately, some people
have used his paper as a model of how phylogenetic nomenclature would
be used.  On the contrary, the PhyloCode explicitly prohibits basing
clade names on specific epithets, as Pleijel did.

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