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Re: Science feather strength debate

> On 11/4/2010 10:09 AM, Don Ohmes wrote:
> Also -- if some flightless birds retain asymmetrical vanes, while others
> don't, and those birds that do not have them are "further" from their
> earlier volant state -- then that would tend to support the notion that
> asymmetrical vanes evolve under flight conditions, would it not?
Non necessarily, because you may have assymetrical vanes appearing
before or together with flight. Someone knowing more about pennaceous
feathers in non-avialians may tell us if the assymetrical vanes are
actually derived with respect to symmetrical ones or not.