jgrehan at SCIENCEBUFF.ORG
Fri Oct 3 10:58:32 CDT 2003
A couple of (possibly ignorant since I have not kept up with some of the
conversations) comments on some earlier postings
> > At 12:09 PM 10/3/03 +1000, Don.Colless at CSIRO.AU wrote:
> > >The amusing fact is that cladism is absolutely essentialistic. Its taxon
>names are rigidly defined by a set of necessary and sufficient conditions:
>the posession of what are BELIEVED to be unique apomorphies (by, of
>course, a set of self-appointed Sherlock Holmes').
I wonder if labelling cladistics as essentialist makes any real difference
to anything. Anything that is not spaito-temporally contingent may be
essentialist and probably any definition that fails to accommodate space
and time. Thus, species definitions that one usually hears about from mate
recognition to reproductive isolation may all be seen as essentialist. It
may be that all classification is essentialist. I am not aware of anything
fundamentally different between cladistics and any other technique in this
respect (although I would enjoy seeing what might be said otherwise).
> > From: Thomas Lammers <lammers at VAXA.CIS.UWOSH.EDU>
> > Not only that, but I find it's handmaiden, molecular biology, to also be
I for one do not see molecular biology as the handmaiden of cladistics. I
am happy enough to work with cladistic techniques without buying into
so-called molecular 'cladistics' (as I've said on the list before, I do not
see molecular genetic characters as cladistic so the result is no more
cladistic for being run through some kind algorithm to construct the
>We are told that the phenotype is merely a
>corrupt and imperfect reflection of the underlying truth, the eidos or
>essence -- the genotype.
>We should not dwell on mere earthly flesh, but
>keep our mind on this sublime spiritual perfection.
>Aristotle and Augustine of Hippo would be so proud ...
> > Thomas G. Lammers, Ph.D.
I agree that is how molecular geneticist have caste the picture, but what
is more bizarre is to see morphological systematists also buy into it.
>+ + Not to beat a dead horse, but the advances in Angiosperm taxonomy are
>primarily due to results from chloroplast genes (prokaryote DNA), which are
>not expressed in the phenotype (they actually are so valuable since they are
>not involved in the sexual game).
>Paul van Rijckevorsel
I have doubts about how much of this constitute 'advances' particularly
when some of the practitioners are grossly ignorant of plant morphology to
the extent that they (those that are constructing trees for angiosperms as
a whole) are not even familiar with the full range of families. I asked one
molecular geneticist at the Pennsylvania State University, for example,
about how the Podostemaceae fitted into their picture, particularly with
respect to the lack of structural homology with the absence of a shoot/root
separation in development, the lack of roots, and problems in the homology
of floral structure the response was one of complete indifference. This
seems to be the pattern overall, that molecular biologists declare
morphology dead (essentially, if I may use that word) on the trash-heap of
history, so therefore they need not know anything much about it.
Finally, as one practicing cladistics, I have no inclination towards the
phylocode. Any move to subvert the written word for numbers leaves me
suspect. Look what happens when the principle is applied to people.
ever present reactionary
Dr. John Grehan
Director of Science and Collections
Buffalo Museum of Science
1020 Humboldt Parkway
Buffalo, New York 14211-1293
Voice 716-896-5200 x372
jgrehan at sciencebuff.org
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