Farewell to Species - and Nomenclatural Stability

Stuart G. Poss Stuart.Poss at USM.EDU
Mon Feb 14 09:33:57 CST 2000

Thomas DiBenedetto wrote:

> If, by traditional, you mean pre-evolutionary, then I agree. Phylogenetic
> concerns in the field of taxonomy are still relatively new. For me though,
> that does not mean in any way that a non-phylogentic, a non-evolutionary
> taxonomy should be considered acceptable anymore. How much longer will it be
> until the evolutionary perspective is fully integrated into the conceptual
> architecture of biological thought?

Its remarkable how Darwin and quite a few evolutionary theorists including and
through Watson and Crick managed without the revisionism to make as much
progress as they did.

> Naming a species entails simply
> recognizing it as distinct from all other species, and hypothesizing a
> higher level grouping ( a genus) of which it is a part. That hypothesis
> might change,,,so what?

So we seem to agree that knowledge of phylogeny is uncecessary for nomenclature
and alpha level
taxonomy, although I would hope that you recognize that naming a species is in
fact a hypothesis as well, assuming that one has a reasonably objective
definition of what a species is.

> I dont see systematics or taxonomy having much of anything to do with
> ancestor-descendant relationships. "Alpha" taxonomy is about identifying
> distinct, previously unrecognized terminal taxa (new species), or
> revistiting previous proposals of that type. Systematics is about
> discovering the sister-group relationships of taxa. Ancestor-descendant
> relationships seem to me to be outside of the purview of empirical science.

Another important objective of alpha taxonomy is to keep track of names so that
they are consistently used.  I have noted that even cladists seem at times to
disagree as to what taxa should be included under the use of a given (higher
category) name.  Even accepting the proposition that nomenclature must conform
to a particular set of phylogenetic naming conventions, this important aspect
of alpha taxonomy will not disappear, in fact the problems will become much
more accute, since there are so many more possibilities for disagreement as to
what name should be employed in a given instance.  The number of possible
phylogenies is very much larger than the number of species or currently
existing names.  If our ability to distinguish names is based upon the
interpretation of a given phylogeny, then the task of using names consistently
will be much more daunting than it is now.

To me the above seems a very curious statement of what Systematics is.
I prefer to conceive of it more broadly than simply ellucidating cladistic
propinquity, important as that is, since one may also be interested in testing
how selection can lead to parallelism or independent "solutions" to a variety
of "evolutionary problems" confronted by organisms.  For this reason, I have
always found Simpson's definition that it includes the study of "any and all
relationships"  among organisms acceptable, although I would certainly agree
that some "relationships" are much more interesting than others.

Further, the issue of anscestor-descendant relationships can not be viewed as
distinct from cladistic inference, since one is always confronted with the
reality (assuming the revisionism you propose has not discarded Darwin
entirely) that such a mechanism is necessary to acheive any cladistic
hypothesis.  The distinction between "alpha" and "beta" level taxonomy is not
as great as it might appear in theory because we are always confronted with the
problem of how do we resolve the differences we observe among organisms,
however grouped.  By permitting observations and definitions that seek to
establish such resolution that do not in principle necessarily conform to
phylogenetic theories,  we do not place restrictions our ability to test such
ideas scientifically.

> But to your more general point that taxonomy should not be based on
> systematics, but rather vice versa, I disagree. How could one discover
> anything about phylogeny through the use of non-phylogenetic taxonomy?

Just how did Darwin manage or would you say that Darwin too was

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