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Re: more bird origins
In a brief message dated 96-10-03, George Olshevsky comments that "...a
skydiver equipped with parachute and harness easily weighs 200+ lbs (even
without a tail) and falls like a rock;...". Obviously, George has never seen
me in flight! I AM "...a small, [not yet] feathered, [but I'm trying!]
lightweight falling/gliding creature..." (and there's a special adaptation in
my jumpsuit that lets me extend my tail once clear of the jump plane... ;-)
While the early gliders undoubtedly had the advantage over humans with
respect to the bouyancy of the atmosphere with respect to their bodies, I
think the instability problem still exists for them. They would have a less
rapid/severe loss in stability than our denser forms impose upon us humans,
but the analogy holds. The tail would undoubtedly help; in the gliding
process, stability is achieved in large part through symmetry. The prime
example is deployment of canopy; one must utilize ONE arm for deployment, and
the other as a stabilizer - generally, extended above the head. This is
analogous to the tail.
By the way, skydivers do not fall like rocks; a great deal of control can be
had over fall rates (I can range from roughly 95 to 130 mph, at will) and
direction. Once terminal velocity is reached, you'd be surprised how stable
and manoueverable your body can become.
Now, if I can just get those wings to sprout on the leading edges of my
wings... er, arms...
Wayne A. Bottlick