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Re: Cladistics (was Sci. Am. - present)



At 07:45 AM 2/20/98 -0600, chris brochu wrote:
>How would you "improve" a parsimony analysis?  I'm not trying to be
>patronizing - this is a serious question.  Given the principle of 
>total evidence, the hypothesis that best matches all the available 
>data is the preferred one

Which, in general, is the Maximum Liklihood Estimate, when such is available.

At present, MLE's are only available for genetic phylogenies.  However, a
recent article in _Systematic Biology_ on the subject has increased my hope
that an MLE approach may be soon available for character data.

> - are you advocating some sort of 
>significance test for character data?

Well, that would be nice.

Even better: a significance test for relative strength of cladograms.  Then
all cladograms that are not significantly less parsimonious than the best
one could be considered equal to it in parsimony.

Those are the two changes *I* would like to see.


If it turns out that Maximum Parsimony *is* the MLE for character data, so
be it.  But, based on the preliminary results in the paper I mentioned, I
doubt it will turn out so.
--------------
May the peace of God be with you.         sarima@ix.netcom.com
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