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Re: Greg Paul is right (again); or "Archie's not a birdy"... but Jeholornis is (not!))
In a message dated 8/7/11 8:12:46 PM, email@example.com writes:
<< Before I respond to GSP's post, I think it's pertinent to mention that
this thread began as "Greg Paul is right (again)" because a single
phylogenetic analysis with a single new taxon (_Xiaotingia_) recovered
_Archaeopteryx_ inside the Deinonychosauria clade, and outside the
line that led to modern birds. This accords with GSP's long-held
views on the position of _Archaeopteryx_ vis-a-vis deinonychosaurs -
hence the ensuing victory lap on the DML. But if another analysis in
the future (perhaps one that uses an expanded dataset) fails to find
support for this topology - will that prompt a message entitled "Greg
Paul is wrong (again)". I hope not, because that seems awfully unfair
to GSP. It also seems irrelevant, because GSP does not subscribe to
cladistic methodology, so it seems odd that a phylogeny based on a
methodology that he derides could be cited in support of a
non-cladistic, intuition-driven hypothesis advocated by GSP. >>
This is the kind of criticism/question I like because it is a valid issue.
Here's how it works from my end. I have long advocated that all Cretaceous
theropods (deinonychosaurs, therizinosaurs, oviraptorosaurs) sporting
assorted flight adaptations are neoflightless for a variety of logical reasons
won't repeat here. I have so far dismissed cladistics because they risk
producing misleading results due to a lack of sufficient fossil taxa to
sufficiently test alternatives especially when lots of functional reversals
an old lifestyle is returned to. Sure enough, as the fossil data base
expands cladistic studies are increasingly supporting parts of my hypothesis.
of course I tend to go for those results. I predict future discoveries will
further verify the neoflightless hypothesis. But as Dan C pointed out we are
likely never to fully be able to settle the issue for the obvious reasons.
A similar situation occurred with whale origins. Cladistic analysis did not
settle the issue for many years. Then more and more transitional fossils
showed up, combined with molecular studies, and now whale origins are much
better understood. The cladistics sort of went along, but just good
observational analysis was sufficient (as it was to show humans are apes,
derived therapsids, birds and derived dinosaurs, etc before cladistics).
Cladisitic analyses can be useful but are inherently limited in their
effectiveness and can be exercises in futility that are taken much too
really the fossils that count.