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Re: Flight again (was Re: The Lizard of Oz)

> asymmetrical feathers are not required for lift production.  However, the
> of the moult is cheaper if the lifting feathers are asymmetrical because
> asymmetry allows use of a less massive shaft.  Is it possible that moult
> expenses are related to development of asymmetry in flight feathers?

Given that all flightless birds moult... don't they?

> David Marjanovic and someone else [HP Tim Williams] wrote:
> > > This design
> > > pre-adapted the symmetrical vaned feathers for lift.  The wing
> > > then
> > > became asymmetrical.  Evolution of flight by successive exaptations.
> >
> > Of course by successive exaptations!