Re: Gliders to Fliers?

[Andrea Kirk <kirkam@wam.umd.edu>]

> But, to answer you question: yes, the limbs, while somewhat modified, are
> like those of all birds, with a spalyed, horizontally placed femur -
> something we see as well in all the volant forms.  And, the ostrich has
> wings which are now vestigal, but were most probably once used ancestrally
> for flying and getting up into trees.  The rigid backbone, the modified
> supracoracoideus, the still large pectoral muscles, etc., being yet other
> characters of once flying, and hence arboreal, ancestors.
>

Just sort of a thought that popped into my head...I don't know enough morphology
or physics to do more than keep up with this thread, but does flying really
imply arboreality?  (Is that really a word? =)   For example, were pterosaurs
arboreal?  Could their feet lock on a perch like a bird's?  Or did they evolve
from a known arboreal animal?  Would a flying animal evolve for a reason other
than getting into a tree?  (The "chasing insects" hypothesis comes to mind
here.)

Andrea Kirk