Re: Shaking up the bird family tree

[Michael Habib <mhabib5@jhmi.edu>]

> Well, if we consider that we could induce teeth formation in chicken
> beak, loss and regain of complex character do not seem to be so
> impossible.

True, but the switching of teeth is largely a regulation change.  Tooth 
formation can be switched on with little trouble, because the rest of 
the developmental pathway is still intact.  Even then, the teeth are 
small and fairly non-functional.

In avian wing reduction, by contrast, we tend to see a more complex 
reduction in several continuous characters (forelimb skeletal 
characters, flight feather production, sternal complex robustness, 
pectoralis mass, etc).  Simple up-regulation changes are unlikely to 
re-induce full flighted ability in neoflightless birds.

Still, we shouldn't consider it impossible, just complicated.

Cheers,

--Mike


Michael Habib, M.S.
PhD. Candidate
Center for Functional Anatomy and Evolution
Johns Hopkins School of Medicine
1830 E. Monument Street
Baltimore, MD 21205
(443) 280 0181
habib@jhmi.edu