Re: Shaking up the bird family tree

[Mike Habib <habib@jhmi.edu>]

> We could do an allometric studies... But in principle all those
> reductions could be controled by a single gene - if it is placed in
> the right point of developmental control cascade: say, one that
> control the AER tempo.

True; that is a possibility, which is why the rapid regain of the  
functional flight apparatus is still a possibility, albeit still a bit  
of a long shot..  There could be a small number of genes involved, but  
the current evidence does not seem to support such a simple timing  
switch for all of the aforementioned traits (and avian development is  
pretty well known, at least assuming chicken models are applicable to  
other groups).  Quite a few of them could be affected in unison via  
timing mutations (especially sternal complex and pectoralis mass).   
However, wing length and forelimb structural strength appear to be a  
bit more complicated.

Like you said, a combination of allometric studies and genetic timing  
research might better determine likelihood.

Cheers,

--Mike H.


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