Re: Big-brained birds evolve faster

[Michael Habib <mhabib5@jhmi.edu>]

> http://www.journals.uchicago.edu/doi/abs/10.1086/589461
>
> http://www.sciencedaily.com/releases/2008/08/080814210006.htm

A neat paper.  I've only had a chance to go throw it quickly, thus far. 
 I'll give it a closer read when opportunity arises.  My first 
impression, though, is that the dataset is strong and the analyses well 
conceived, but the conclusion may be a bit hasty.  Specifically, the 
correlation with brain size may be a result of control system 
differences rather than the kind of cognitive function that the authors 
suspect.  Either one would make sense, and it's not clear (to me, at 
least) why one would be favored over the other.  Work on brain size and 
planform in bats has demonstrated that more highly maneuvered, 
low-loading morphologies are associated with larger brains (and that 
this appears to be related to flight control and sensory perception).  
There may be something similar happening in birds.  I'm curious to hear 
what others think.

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