Re: numerical taxonomy

[Una Smith <una@xxxxxxxxxxxxxxxxxxxxxxxxx>]

D. B. Scott <COLLINS@ac.dal.ca> wrote:

> I think the problem is that people assume when you do something numerical
> it is automatically objective but they forget that the characters that are
> chosen to do the numerical analysis are chosen subjectively ...

Yes.  One major benefit of cladistic (and phenetic) analysis is that the
subjective choice of which characters and character states to include
can now be evaluated, at least to some extent.  For some groups, such as
angiosperms (flowering plants) above the family level, a time may come
very soon when the choice of characters to use is not at all subjective.

I think we might come to agree on the characters to use to resolve the
higher systematics of angiosperms before we manage to resolve the higher
systematics, as we learn what characters are consistently informative
about relationships among subsets of the group!  Some ~300 angiosperm
families are traditionally grouped into subclasses and orders within two
classes, the dicots and the monocots.  We're starting to find evidence
that most of these taxa above the family level are paraphyletic and/or
polyphyletic.  It's a big mess, and phylogenies based on molecular data
are crippled by computational barriers so huge that interest is rapidly
returning to traditional morphological and anatomical characters, and to
fossils.