Monday, October 10, 2005

Phony feathered dinosaurs?

According to a recent article from the Journal of Morphology (subscription required), the integumentary filaments of those famous feathered dinosaurs are nto feathers at all. According to Alan Feduccian and colleagues, the filaments observed are evidence of decaying collagen. Fair enough. This would be very interesting to know, and would be a welcome challenge. The problem is that since Feduccia and company have been embarrassed countless times, they will do most anything to try to save face. This massive, 47-page article in J. Morph. stands as a testiment to their zombie-like resiliance.

While the integumentary filaments of the dinosaurs from eastern China may, in some instances, represent frayed collagen fibers from the sub-epidermal tissues there are a number of patterns which remain to be explained. Chief among them: why don't the countless crocodiles, lizards, and turtles from these sites show similar filaments?. Why is it that only the birds and the dinosaurs from the Jehol biota happen to have these integumentary filaments? Do crocodiles, lizards, and turtles not have these? That would be really interesting since Feduccia et al. referred to specimens of each of these groups for their studies. They provided no comparative evidence from other reptiles from this site that would corroborrate their hypothesis.

Especially interesting is the following statement. Because Feduccia et al. have already decided that birds could not possibly come from dinosaurs, they choose to dispute the phylogenetic position of feathered dinosaurs such as Caudipteryx with this kind of hand-waving:
That phylogenetics has become an assumptionladen
field is best illustrated by the insistence that
the avian wing of Caudipteryx, with its intricate
detailed flight anatomy and avian arrangement of
primary and secondary feathers on the hand and
arm (Fig. 26), evolved in a context other than flight

Well, how convenient. Little do they realize, it doesn't matter if these animals are secondarily flightless birds. The question of explaining the enormous number of characters they share in common with birds remains the important evolutionary question. They have simply chosen to deny the overwhelming character data in favour of their pre-conceived notion that birds could not have descended from dinosaurs.

The absolute icing on the cake is this tacit appeal by Feduccia to creationist reasoning as support for his ideas, from Science Daily:
The theory that birds are the equivalent of living dinosaurs and that dinosaurs were feathered is so full of holes that the creationists have jumped all over it, using the evolutionary nonsense of ‘dinosaurian science’ as evidence against the theory of evolution

This is not just pure bollocks, it's blatantly irresponsible. Thanks a lot Feduccia! Thanks very much for that. While you're at it, why don't you cite the Grand Canyon as evidence against modern geology! Good job!

More on this tomorrow. It's late here.

5 comments:

God Fearing Atheist said...

Whats even more ironic about the creationist comment, Martin, is Feduccia's quote-mining of Greg Paul in the same paper.

"As Paul (2002, p. 179) correctly notes, “Euparkeria [Trias. S. Africa] is a suitable ancestral type for birds … and … Euparkeria
is a good ancestral type for all archosaurs.”

Context is important, Feduchebag. I.e.:

"Few dispute that Euparkeria is a suitable ancestral type for birds. But it is suitable only in the same sense that an early Cenozoic, primitive, generalized primate is a suitable ancestral type for humans. In addition, there is no evidence of flight-related adaptations. Euparkeria is important to bird origins only in that it represents the earliest Mesozoic and most primitive archosaur stem stock from which the entire dinosaur-bird clade later evolved. For that matter, Euparkeria is a suitable ancestral type for virtually all dinosaurs."

I counted literally dozens of hilarious gaffs like this, ranging from wildly out-of-date (and made up..."microsaurs"? There's a Microsauria?) nomenclature to confused theropod anatomy and everything else inbetween.

Martin Brazeau said...

Thanks, GFA! The level of quote-mining in that paper is unbelievable. What gets me is the amount of emotive language they use while accusing other authors of being so.

The part that gets me the most is their claim that palaeontology and developmental biolog disagree on the homology of digits in birds and dinosaurs. Sure, if you take an incredibly naïve view of developmental biology. Developmental biology has been increasingly instrumental in helping us understand modularity in animal morphology. Basically, we now have a handle on how it is that different morphological identities can disagree with positional identity. Case in point: the anal fin and second dorsal fin of the coelacanth have paired fin identity. Yet, they themselves are unpaired median fins. Would Feduccia et al. propose that these fins are not homologous to the second dorsal and anal fin of other sarcopterygians?

God Fearing Atheist said...

Yes. Its sad that Feduccia will still rely on the naive notion that digit number must necessarly equal condensation number EVEN THOUGH its an experimental FACT that this is not always the case.

Martin Brazeau said...

Indeed. This is partly why I haven't followed up with that entry (despite having said "more on this tomorrow" - I was on a plane the next day). I want to follow this up with a more complete discussion of modularity... just as soon as I can figure out how to get posted pictures to work on this thing! It appears to be a Mac compatibility problem.

Willie said...

How did they resolve the issue? Did you have to call them or email them?
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