Latin names versus scientific names [was: So much fornomenclatural stability]

[Richard Jensen]

I'm not sure I follow what Curtis writes below.  Just to make sure we're
all on the same page, a monothetic set is one for which the possession
of a single characters state (or a unique combination of character
states) is both necessary and sufficient for membership in the set.
This is not the same as monophyly and cladistic classifications are
rarely monothetic (most have too much homoplasy to recognize strictly
monothetic sets).

Now, I can see how apomorphies "below" a node might be used to support
monophyly - as we are moving up that part of the tree, all taxa share
these apomorphies (which are equivalent to synapomorphies).  However,
apomorphies above a node provide no basis for declaring that all taxa
arising at that node are monophyletic.  If they did, they would be
synapomorphies at that node, right?

Dick J.

Curtis Clark wrote:

> on 2005-03-10 05:27 Thomas G. Lammers wrote:
> > [...] monothetic view of
> > cladistics.
>
> This is a common misconception. Even if there is only a single
> synapomorphy at a node, a cladistic classification is in no sense
> monothetic, since all the apomorphies above and below that node also
> help support its monophyly.
>
> --
> Curtis Clark                  http://www.csupomona.edu/~jcclark/
> Web Coordinator, Cal Poly Pomona                 +1 909 979 6371
> Professor, Biological Sciences                   +1 909 869 4062

--
Richard J. Jensen              | tel: 574-284-4674
Department of Biology      | fax: 574-284-4716
Saint Mary's College         | e-mail: rjensen at saintmarys.edu
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