development and evolutionary origin of feathers

[Kendall Clements <k.clements@auckland.ac.nz>]

The recent discussions on maniraptorian arms and the role of feathers 
reminded me of the recent paper by Richard Prum. The reference is:

Prum, R.O. (1999) Development and evolutionary origin of feathers. J. 
Exp. Zool. (Mol. Dev. Evol.) 285: 291-306.

I found this an excellent paper, full of detail and solid reasoning. 
Since it makes several authoritative conclusions concerning the 
sequence in which feathers must have evolved (in avian and non-avian 
dinosaurs) it is highly germaine to the recent discussion. So I went 
and searched the archives, thinking I must have missed discussion of it 
on the list at some time. I found only one reference to the paper, in a 
message from Luis Rey on 18 April this year. Another posting lists Prum 
as having attended the feather symposium, but doesn't discuss the paper.

In the interests of promoting informed debate, I'd like to know what 
list members think of this paper. Prum concludes (p. 302): "the 
aerodynamic hypothesis for the origin of feathers is incompatible with 
the most salient feature of feather development - the cylindrical 
nature of the follicle. Further, the bipinnate structure of feathers 
could not have evolved by selection on increasingly elongate scales for 
an aerodynamic function. Some feathers did ultimately evolve an 
aerodynamic function, but selection for an aerodynamic function could 
only have taken place after the evolution of the closed pennaceous, 
bipinnate feather."

Kendall

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Kendall Clements
k.clements@auckland.ac.nz