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Re: cladistic taxonomy



On Tue, 8 May 2001, Ken Kinman wrote:

>      I guess Eureptilia would at least be better than Reptilia.  While on
> that subject, I wonder how you can easily explain to non-cladists the
> difference between node-based and stem-based definitions, and that although
> each are given different names in the name of precision, they can end up
> having essentially the same contents (i.e. include the same taxa).

This problem appears more frequently in Linnaean taxonomy, actually. E.g.,
Archaeornithes, Archaeopterygiformes, Archaeopterygoidea,
Archaeopterygidae, Archaeopteryginae, Archaeopterygini, and
_Archaeopteryx_ all having the same membership. In cladistic taxonomy,
only two clades in each case can be different while having the same
membership.

The simplest explanation is that they are only *currently* identical. New
discoveries of more primitive forms will yield sauropsids that are not
(eu)reptilians.

>      I wonder if Cetartiodactyla and Eparctocyona (the latter slightly more
> inclusive?) is an example of this kind of hair-splitting precision or not.
> Might be an interesting case to look into.

This may be getting a bit off-topic, but I don't understand
_Cetartiodactyla_ ... seems to me it's the same as _Artiodactyla_ -- the
question being whether _Cetacea_ belongs in _Artiodactyla_ or not.

(What is Eparctocyona?)

> P.S.  I am certainly not alone in seeing all this precision and phylocoding
> as making nomenclature and classification increasingly difficult to
> comprehend (much as our legal system is).

Bah. I understand it fine, and I've only had one class that even touched
on it (and it wasn't even the focus of the class). I think it's more a
matter of people being too attached to the old system, which is at least
as difficult to master.

If you know only English, Japanese seems hard. But if you know only
Japanese, English seems hard. It's not really possible to say that one is
more difficult than the other without some kind of cultural bias.

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