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Re: flapping from gliding

From: Ronald Orenstein <ornstn@inforamp.net>
 > At 12:44 27/09/96 -0500, NIck Longrich wrote:
 > >    That thing with the big scales on it's back George talks about a
 > >lot and I can't remember the name of. (extinct)
 > Longisquama

Though I still cannot see how this beastie could be a glider.
The "fins" seem to be placed incorrectly for airodynamic purposes.

 > >    The point:
 > >The arboreal hypothesis has two main strengths. a) the leap between
 > >gliding flight->powered flight seems to me to be...
 > >an easier one, than the one between a running or leaping
 > >predator and powered flight.
 > EXCEPT - if gliding has evolved so frequently ... why did powered
 > flight evolve only
 > three times in tetrapods?  If this were indeed the pathway I would have
 > expected a lot more flyers.  The fact that flight has evolved so rarely
 > suggests to me that it developed by an infrequently, not a frequently,
 > "chosen" pathway.

Hmm, good point.

However, is it no possible that the "difficult" step is the transition
from gliding to powered flight?

This certainly goes with your point that the two require different
types of arm motion.

swf@elsegundoca.ncr.com         sarima@ix.netcom.com

The peace of God be with you.