[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: flapping from gliding

George Olshevsky wrote:

>This seems perfectly reasonable to me. The important thing is that the
>gliding animal is airborne, and it achieves control over its trajectory by
>moving, folding, and extending its forelimbs (and other body parts, such as
>the tail and hind limbs) as needed. Hand-eye coordination improves,
>aerodynamic control improves, and over time, powered flight evolves. All
>perfectly natural, and in the absence of clear evidence to the contrary,
>almost certainly the most parsimonious hypothesis about the origin of flight.

I'm still not at all sure it is so natural.  Manouevering an airfoil is a
very different procedure from sustained powered flapping, and as I have
suggested the latter could have evolved without the former.  Has anyone ever
done an aerodynamic or mechanical analysis to determine the likelihood of
such a transition, or are we all just making assumptions based on what
"sounds right"?
Ronald I. Orenstein                           Phone: (905) 820-7886 (home)
International Wildlife Coalition              Fax/Modem: (905) 569-0116 (home)
Home: 1825 Shady Creek Court                  Messages: (416) 368-4661
Mississauga, Ontario, Canada L5L 3W2          Internet: ornstn@inforamp.net
Office: 130 Adelaide Street W., Suite 1940    
Toronto, Ontario Canada M5H 3P5