Who is the postivist? AND Popper

[Thomas Schlemmermeyer]

James,
>=20
> > Popper admits that evolution is metaphysics!!!
>=20
> =09He was talking about natural selection.
>=20
Sorry, it has been already a long time ago when I read Popper's=20
autobiography where he put his thoughts in favour of evolution as
a metaphysical research program, but I still remember that Popper
perceived well the relations between=20
=09=09=09=09=09natural selection
and
=09=09=09=09=09adaptation.

The theory of natural selection is tightly connected to the idea of
adaptation. Adaptation was intrinsically metaphysical as it could not be
falsified. Every organism was seen as adapted.

There are however some experiments which visualize processes which really
make plausible the concept of selection leading to adaptation
(Replica-plates of bacteria cultures in different media).

In the context of phylogenetic reasoning it was already tried to put
adaptation on a more solid ground.
Adaptation in this context would be the derived character state, whereas
the generalized character state would be still the unadapted.

>=20
> =09Let me give some real examples.  Conservation biologists have
> =09happened upon the idea that evolutionary trees might be useful to
> =09indicate which taxa are distinctive, and therefore deserve
> =09the highest conservation priority. =20

What makes them think that distinctive taxa deserve the highest=20
conservation priority?
What is the logic behind this?


=09Such taxa, as distinctive
> =09as they are, might tend to mislead parsimony by branch
> =09attraction. =20

=09A more severe, critical test (references
> =09available) points out (a) the taxon is on a long edge, and
> =09therefore (b) it is likely to be misplaced in the=20
> =09parsimony tree.  Popper's relevance is that he always
> =09insisted on the use of the most critical tests.

Ok, these are thoughts which deal intrinsically with tree pattern
and tree topology questions. Maybe in two weeks I'll understand them
better, but, so far, I'm still very Hennigian and I think in
Homology and synapomorphy.

But, James, are you only talking about topological trees, or do you have
any real case-studies in mind, with real, living biological organisms?

Or would it be far more intelligent to substitute in these conservation
questions organisms and taxa by whole ecosystems?????

yours     Thomas
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Thomas Schlemmermeyer
Museu de Zoologia, Universidade de S=E3o Paulo
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