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Re: propaganda of the majority
>Nevertheless, the vast body of evidence supports the dinosaurian
>hypothesis. Martin and his crew have not adequately demonstrated their
>crocodylomorph-origin by cladistic method: it would be good if they did,
>since I would be willing to be convinced by superior data.
No doubt about it, there is _more_ evidence for a dinosauria->aves
relationship than crocodilia->aves. However, it should be noted
that alot of this case that's been built for the dinosauria->aves
connection is based on the foundation of cladistic analysis. I don't
think I'd ever be convinced by cladistics data alone for 2 reasons:
- There's way too much subjectivity in choosing characters for
- No standard methodology exists for differentiating between similarities
inherited from a common ancestor and similarities due to convergence.
>Luis Chiappe has already run the test that should be done (i.e., include
>both crocodylomorphs, dinosaurs, primitive birds, and advanced birds) in the
>same analysis. His results supported the theropod origin.
I have not yet seen Chiappe's study, but I'd like to add a few more
general comments about cladistics analysis shortcomings.
If you have ten cladists do an analysis on a data set, you will get up to
ten different results. At best, you know only one of them can be right.
This illustrates why Martin et al become upset by the rather dogmatic
statements that have been made over the past several years (Padian and
Gauthier, etc.) which imply that because you've done a cladistics analysis
you've somehow arrived at the truth.
>And to explain some of my views, I was John Ostrom's last offical Ph.D.
>student before his retirement. I can tell those of you in the cyberaudience
>from personal experience, the similarities between Archaeopteryx, Sinornis,
>and other primitive birds on the one hand, and advanced maniraptoran
>coelurosaurs (in particular, velociraptorine dromaeosaurids like Deinonychus
>and Velociraptor) are amazing. A quick note, my support for the placement of
>Archaeopteryx among the various theropod lineages will be in print at the
>end of the year in the Journal of Paleontology. I would be interested in
>hearing from those who have evidence which conflicts with the theropod
>origin and/or supports the crocodylomorph origin: it might be informative
>for those on the net who aren't professional evolutionary biologists to see
>how systematics works.
We had some discussion on this about a month ago. John Ostrom is a hero
of mine, but I do pick a bone with his cursorial origin of flight theory.
I could repost all of my questions/problems regarding the theropod-bird
hypothesis if you missed it.