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Re: 11th specimen of Archaeopteryx



Personally, I think that too much is made of the asymmetrical remiges, in 
general.  Some considerations in that regard:

1) Asymmetrical vanes may be functionally advantages in ways other than lift 
production
2) Asymmetrical vanes are not required for effective flight (despite claims in 
the literature to the contrary)
3) Symmetrical vanes may not have been the developmentally ancestral condition 
for contour feathers.  Granted, they probably are, given the fossil record of 
feather evolution, but there is still the possibility of secondary flight loss 
in the mix that makes it difficult to confidently claim that the first true 
"contour" remiges were symmetrical.  Secondarily flightless birds do not 
necessarily "mirror" incipient flight evolution.
4) Even if we assume that asymmetrical vanes evolved under selection for 
mass-efficient generation of fluid forces, there are plenty of ways to use such 
forces other than weight support.  WAIR is just one of them.  The other 
potential advantages do not all involve getting into high places.

--Mike


On Oct 24, 2011, at 1:20 PM, Matthew Martyniuk wrote:
> What about the asymmetrical remiges? If Archie and/or its ancestors
> were not at the very least using WAIR (to get up into high places,
> presumably), why did they evolve? Symmetrical remiges are just as good
> as asymmetrical for brooding nests, display, or any other alternate
> uses of the wings that have been proposed.
> 
> Matt

Michael Habib
Assistant Professor of Biology
Chatham University
Woodland Road, Pittsburgh PA  15232
Buhl Hall, Room 226A
mhabib@chatham.edu
(443) 280-0181