Convergence Test for Cladistic Analysis

["John P. Poynter" <JohnPPoynter@msn.com>]

Ladies and Gentlemen:

I've been following with great interest and small understanding the 
thread(s) on cladistics.  I believe I generally understand the principle 
behind cladistic analysis, in that the grouping of characters from most 
common to least common (with some [subjective? non-subjective?]) weighting 
of the characters) will produce nested sets of species.  I think I am 
beginning to understand the importance of the identification of convergent 
characters, in that their inclusion in a cladistic analysis will lead to 
errors in the result.

My idea of the process all of you are going through is that you are 
developing cladistic analyses, and comparing them to discover which one is 
correct.

In mathematics the study of the convergence of a series involves a test for 
convergence.  (That is, "Is the answer I just got better or worse than the 
previous answer?")

If I understand what you all have been saying, parsimony cannot be the 
test.  Parsimony is one of the tie-breaker rules by which results are 
obtained.  Use of parsimony as the test for convergence would be circular 
reasoning.

So, here're the questions:
1.  What formulation is used to test the divergence of a cladistic analysis 
from the ideal cladistic analysis?
2.  What is the ideal cladistic analysis?

I will stipulate now that these are "pure" questions; I haven't got a clue, 
and I am not pushing an agenda.  Actually, I doubt I'll live long enough to 
understand enough about the subject to voice a meaningful opinion.  But I'm 
having a good time trying.

Jack P.
Eoprogrammerus Informaticus

Non Significat Si Non Pulsatur.  Proposed motto (Time Magazine) for Count 
Basie's coat of arms.