hypothetical construct

[Richard Zander]

Tom DiBenedetto wrote:
>
> sylvia hope wrote:
>
> >         The point I meant to
> >          make is that the term  "synapomorphy" reifies the
> >          idea of homology.  It makes a relationship of homology seem
> >          to be a real, solid thing, whereas it is really only an idea
> >          about the correspondence among organisms - there is no real
> >          entity there.
>
> I disagree. Homology is real. It is biological structure or form
> which is passed from generation to generation amongst organisms
> throught the information transmission processes of genetics and
> epigenetics. Of course, our formulations of specific homologies might
> be over-extended or might be simply wrong, but we are trying to speak
> to something real. Synapomorphy refers to those homology hypotheses
> which we 'believe" to be correct at a particular moment in our
> scientific enterprise for they have passed all the tests we threw at
> them, including congruence.
>
> >         Reification is common in an operational
> >          approach.  It can lead via subtle suggestive power to too
> >          much confidence in a finding.
>
> Do you extend this perspective to deny the reality of taxa? Is the
> recognition and naming of Aves (with a proper name, no less) a
> reification of mere ideas?

There are two approaches to viewing hypotheses and theories, realism and
anti-realism. These are much the same, since the first posits a reality,
then says it is correctable, and the second has all the trappings of the
first, but denys the reality (acting "as if"). They are both liable to
generating statistical nonsense. Realism, however, in positing the
reality of patterns, species, synapomorphies, opens the door to low
standards of hypothesis construction. Because realists feel that there
is a truth and that data converge to the truth, hypotheses that maximize
explanation or minimize falisification are presented as "approximately
the truth" even with they are of low probability.
  Yes, the correct hypothesis (if it could be determined with a time
machine) is one of the hypotheses of low probability, but it is the
ability to choose which low probability hypothesis is the true one that
is the problem. Maximizing synapomorphies and maximizing likelihood only
narrows the field by eliminating grossly unreasonable trees.
  Thus, reification associated with realist attitudes introduces
idealist attitudes into realism, which is supposed to be its
philosophically exact opposite.


--

*******************************************************
Richard H. Zander, Buffalo Museum of Science
1020 Humboldt Pkwy, Buffalo, NY 14211 USA bryo at commtech.net
*******************************************************