lonely Dan Janzen

Don.Colless at CSIRO.AU Don.Colless at CSIRO.AU
Fri Mar 26 15:51:31 CST 2004

Richard Pyle wrote:
> many - and I dare say some day nearly all - users also make very
> extensive use of the marvelous inferencial (=predictive) power of the
> phylogenetic components of your classification systems.    You are
> all aware that the more phylogenetically-based your system(s), the
> more inferentially powerful it is for us users.  
that the Linnaean system was suboptimal for communicating inferred
 the use of nomenclature as a tool for the strict
representation of phylogenies inferred from the latest lump of data.

He also offered several wise and temperate comments. But the above quotes illustrate a common non-sequitur that is achieving the status of received truth. To wit:
A. Classifications should be predictive.
B. Cladistic classifications offer the best available predictions of phylogeny.
C. Ergo, classifications should be cladistic.

The non-sequitur lies in just whether it is just phylogeny that we wish to extract from a classification. There are, after all, many other ways of providing that information, which on its own is about as interesting as the ?begat?s in Genesis, ch. 10-11.
I would dare to suggest that a worker interested in an insect?s ability, say, to transmit disease could not care less if the relevant taxon is mono- or paraphyletic. And that that goes for our classifications at large. Also note that classical taxa are generally mono- or para-; we do frown on convergence, and have our ways of minimising it.

Moreover, the much maligned Linnean system is an excellent tool for marking where useful or important information is located. Generic, family, etc., ranks are NOT allocated by an algorithm, as so much beloved by cladists. They result (optimally) from a consensus of conscientious, trained, taxonomic opinion.

Don Colless,
Div of Entomology, CSIRO,
GPO Box 1700,
Canberra. 2601.
Email: don.colless at csiro.au
Tuz li munz est miens envirun

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