Cladistics and Eclecticism

SKÁLA Zdenek skala at INCOMA.CZ
Wed Feb 13 13:50:05 CST 2002

>>...Only if you are defining the right history representation in the sense of
>>holophyly ("including all descendants") you can speak about
>>misrepresentation of history. Eclecticists evidently define right history
>>representation otherwise (having a common ancestor) and hence represent the
>>history correctly. Hence, again, this is a matter of definition what is
>>"true representation" and the discussion could easily become tautological.

>I speak of misrepresentation of history because the tree and the
>classifcation is proclaimed to be reflective of history. Given that the
>history of lineage divergences is the historical framework of diversity -
>given that the tree, if it is to refer to anything, refers to that history,
>... But the
>distortions to the hierarchical framework that are inherent to eclectic
>classification mean that the framework does not represent lineage
>divergences.  Therefore they are confusing misreprentations.

Please, try to read my original statements more carefully; now I cannot do much more than to summarize:
- "Eclecticists" define the historical component of a taxon as "having common ancestor"; it is inherent to all "eclectic" taxa (both holo- and paraphyletic) - there is hence no departure from representation of clades because there exists no intent to represent only clades. Evidently, you mean under history the order of the branching events and to represent history corectly means for you to represent the hierarchy of these branching events. Eclecticists simply mean under history the character change too.
- "Lineage divergence" is to you obviously the branching event; to me "divergence" can have also anagenetic meaning. Let's have a well-supported clade ABCDEF where all internal nodes are weakly supported except the clade EF. Speaking in the phylogenetic terms, the clade EF "diverged" not only from its sister taxon (say clade CD) but also from all the "grade" ABCD. Hence I feel it reasonable to label with a name the taxa ABCD (paraphyletic) and EF. You need not accept my solution, but to me, this solution is to "correctly represent lineage divergence".
This is nothing more than to show you how are such concepts like "true representation of history" or "distortion of lineage divergence" dependent on definitions of the terms. This is also the possible source of circularity - a good reason why to speak more in operational terms than in ontological ones.
Zdenek Skala

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