rankless nomenclature

[Zdenek Skala]

> At 12:59 AM 10/17/00, Zdenek Skala wrote:
> >On the other hand - Mendeelev's table is a good example of how
> >good phenetic system works..
[snipped]
Curtis Clark wrote:
> The periodic table is not phenetic, it is based on specific properties of
> the elements that turned out to result from the properties of electron
> orbitals.
[snipped]
> ...The periodic table is a natural classification, because it
> expresses inherent properties of the elements, subject to discovery.
I agree that periodic table is a natural classification but still it is
phenetic. Phenetics itself need not be necessarily unnatural and
probably all phenetic classifications are "based on the specific
properties" of the OTU's. In my understanding, the phenetic
classifications (together with their hypothetical background) are
based on the processes that are running now and so can be
observed directly. This is the case of Mendeleev's table that does
not involve e.g. the information how the elements appeared after the
Big Bang. On the other hand, Mendeleev have found some really
existing natural pattern; this should be also the structure of any
*good* phenetic classification. For example, even the simple
division of plants into "herbs" and "trees" expresses their "inherent
properties" likewise the Mendeleev's table does.

> I think, though, that the key word in your response is "untestable". I get
> the impression that you believe hypotheses of kinship to be untestable.
Not exactly. Hypotheses of the kinship (in the sense of
phylogenesis), can be made (I leave out the subtle matter if the
cladogram change after adding new data to analysis is equivalent
to hypothesis falsification). But these hypotheses can be made
only under certain model of phylogeny and such models are what
is untestable - cladogram (in the wide sense) depends on the
method used and this  method depends on the underlying model.
However any character matrix can be analysed by virtually any
method and always give sensible results (and leave contradicting
character states to homoplasies etc.), so the mentioned "models"
cannot be falsified, in my opinion.

> If
> in fact you are correct, and if it is also true that observed organic
> diversity is the result of evolution, then systematics is not and can
> never be a science, since its foundation cannot be expressed as testable
> hypotheses.
Here is a mistake in your syllogism I am afraid (mismatch of
equivalence and implication):
The fact that organic diversity is a result of evolution does not imply
that this is the *only* natural pattern that can establish taxonomic
solutions. Organisms are related in many ways and phylogeny is
only one of them.
Best!
Zdenek

++++++++++++++++++++++
] Zdenek Skala
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] skala at incoma.cz