Zdenek Skala Zdenek.Skala at INCOMA.CZ
Tue Aug 22 15:33:05 CDT 2000

> Your problem has also been discussed in philosophy of experimentation. Of
> course, it is difficult to do manipulative experiments with phylogeny, but
> it is by no way impossible! You may think of these homeotic mutations in
> Drosophila.
Yes, or re-synthesis of the hybrid allopolyploids in higher plants.
But it is rather an exception instead of rule and - most importantly -
we cannot know if the course of phylogeny was really the same as we
try to repeat in experiment (the process/pattern problem again).
All what we know is that we succeeded to reproduce the pattern.

> Another question that enters is the meaning of prediction.
> It was shown however that such a strict temporal order between prediction
> and experiment is by no way necessary. It is also possible to make
> predictions which are tested by experiments or observations which happened
> already before the prediction was made.
Well, this was not exactly my point. I mean that e.g. phylogenetic
trees constructed by max. likelihood and max. parsimony differ
because the idea of the process behind differs and that there is
virtually no means how to decide between them. If I will include e.g.
new cpDNA data into analysis, both trees will change, but no data
will enable to distinguish between them. So, these methods are (in
my opinion) better viewed as alternative descriptive approaches to
the variation pattern than testable hypotheses.
] Zdenek Skala
] e-mail:
] skala at incoma.cz

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