Paraphyly and names

[Denis Brothers]

This is the whole crux of the matter. I've yet to see the sorts of
criteria that Zdenek asks for. Some years ago I gave a paper on purposes
and forms of classifications at a Hennig Society meeting (silly me)
where I tried to show some of the advantages of an evolutionary/eclectic
approach (as one way of cutting down on the multiplicity of taxa
required by a strict cladistic classification). One of the participants
indignantly protested that not all clades need be named, so that that
problem did not really exist. But I've never managed to get a good
explanation as to how one then decides which should be named and which
not. I suspect that this is as subjective as how eclecticists decide on
the same issue (basically, "where are the 'significant' gaps?"). The
functions of general-purpose classifications and cladistic analysis must
not be confused. Most people who use classifications do so for reasons
other than identification of the points of origin of evolutionary
novelties.
Denis

Professor Denis J. Brothers
School of Botany and Zoology
(and Centre for Environment & Development)
University of Natal, Pietermaritzburg
Private Bag X01              Telephone: (+27) (0)33-260 5106
Scottsville                        Fax: (+27) (0)33-260 5105
3209 SOUTH AFRICA     e-mail: brothers at nu.ac.za

>>> SKÁLA Zdenek <skala at INCOMA.CZ> 01/30/02 01:43PM >>>
Skála Zdenek wrote:
>> ... You simply prefer to have 2^n-1 taxa (given n=number of
species).
Thomas Pape wrote:
>We seem to agree that there is one particular Tree of Life with
numerous branches. As scientists
>we want to convey information relating to certain branches.

^^^^^^^^^^^
This is the point. Either we will name all clades as Thomas DiBenedetto
apparently proposes or we will select only some of them as named taxa
(not speaking about the paraphyly/holophyly for the moment). In the
latter case we will need some operational criteria to distinguish which
of the clades should be named and which should not be named - that's
all.

Best!
Zdenek