Lucy in Newsweek

John Grehan jgrehan at SCIENCEBUFF.ORG
Thu Apr 1 10:22:35 CST 2004


>John,
>      I agree that genetic claims should be tested with morphology, BUT
> vice versa as well.

Agreed, but a conflict between the two of itself does not give any
indication of which alternative is more correct (as opposed to the popular
assumption that genetics is the test and verification of everything else.

>If your morphological claims are valid, I find it hard to believe that
>there is no genetic evidence to back it up.

'Hard to believe' is a personal choice. It has no scientific status.

>The Angiosperm Phylogeny Group (in spite of my nitpicking at their
>classification) is doing a great job of combining morphological and
>molecular evidence.  Ape phylogeny could benefit from a similarly balanced
>approach instead of looking at it as strictly morphology vs. molecules.

I appreciate that your view of science decision making is that it should
conform to political criteria such as 'balance' but I, for one, see no
scientific validation of political demands. While others might mix and
match morphological and molecular characters, I do not see the latter has
being as defensible as the former (of course I am a 'cladist' of sorts when
it suits me so perhaps this view would not agree with Ken's anyway).

>      As for my supposed "quandry", fossils are obviously NOT meaningless,
> and I don't regard all morphology as unreliable.  I do think some
> morphological characters are more reliable than others, just as I think
> some molecular characters are more reliable than others.  It's just a
> matter of discovering combined data sets in which certain molecules and
> certain morphologies become more and more congruent (just like the
> angiosperm group is doing).

Trouble is that you have already indicated that all morphology is
unreliable or you would not give priority to molecular characters when they
conflict with morphology.

>Instead of criticizing molecular data altogether, I would suggest looking
>for molecular data that is congruent with your morphological data.

If there is reason to, fine. But if the molecular data as constituted does
not necessarily track phylogenetic sequence then there may be no need to.

>Likewise the molecularists need to find more morphological data to support
>their claims of a Pan-Homo clade (and that includes morphological data
>from fossils).

It would appear that molecular phylogeneticists would say otherwise since
only molecular characters are sufficiently reliable in their view to
construct phylogeny.

>Until then I am going to be skeptical about BOTH sides in this debate (and
>since there are more than two possible tree topologies, both might end up
>being wrong, or at least only partially right).  This debate is far from
>being settled one way or the other, and there seems to be too much heat
>and not enough light.
>          --------- Ken Kinman

On this I would agree. What Ken is bringing up is that there is a clear
need for scientific debate on the orangutan issue by primate systematists
and paleontologists, and while neither Ken nor I are really well qualified
to do this (not that this is enough to keep me from speaking out), we are
setting the stage for those who should. I'm still asking, and not getting,
any evidence from paleontologists as to why our fossil hominid 'ancestors'
happen to look like orangutans or why they cannot give me synapomorphies
for their purported human-Australopithecus-chimp clade.

John Grehan

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
Fax 716-897-6723
jgrehan at sciencebuff.org
http://www.sciencebuff.org/biogeography/Panbiogeography/Panbiogeography-Gate.htm
http://www.sciencebuff.org/HepialidaeGate.htm




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