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Re: Science feather strength debate



On 11/4/2010 9:14 AM, Mike Habib wrote:
Not to mention that asymmetrical feathers are not actually required for flight, 
from a first principles standpoint, despite the now popular notion that there 
must be a 1:1 correspondence.

On Nov 4, 2010, at 7:19 AM, David Marjanovic<david.marjanovic@gmx.at>  wrote:

The asymmetrical vanes of the remiges and rectrices of
_Archaeopteryx_ suggest some kind of aerial capability. But not
necessarily powered flight, because _Microraptor_ has them too.

Of course, the only argument against *Microraptor* being a powered flier is the 
same one that holds for *Archaeopteryx* and *Confuciusornis*: its shoulder 
joint.

However, some flightless birds retain asymmetrical vanes (e.g.,
flightless grebes)

Oho. Reference, please?

The fact that some flightless birds *retain* asymmetrical vanes should not negatively affect the status of asymmetrical vanes as indicators of volancy.