More on the 'cladistics' of sequences

[John Grehan]

I have no idea whether the characters below are phenetic or cladistic.

It seems that my exposure to systematics in New Zealand lead to the
distinction of phenetic characters in which there was no distinction
between primitive and derived states (thus the analysis becomes one of
over all similarity) and cladistic characters that were restricted to
those that were considered to be derived. It seems that this usage is
either different from usage in other parts of the world, or between then
and now, or I was misinformed, or I read the definitions wrong at the
time etc. etc.

John Grehan


Disagreeing!  OK, in that case I'll ask you to explain, for all of us,
the
difference between a phenetic character and a cladistic character.
Better
yet, here's a character that I have used in analyses of relationships
among
species of oaks:

    0 = cupule covering 1/4 or less of the acorn
    1 = cupule covering more than 1/4 but less than 1/2 of the acorn
    2 = cupule covering 1/2 or more of the acorn

Now, please explain whether this character is phenetic or cladistic.

Dick

--
Richard J. Jensen              | tel: 574-284-4674
Department of Biology      | fax: 574-284-4716
Saint Mary's College         | e-mail: rjensen at saintmarys.edu
Notre Dame, IN 46556    | http://www.saintmarys.edu/~rjensen