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


>I would guess that any intermediate stages between gliding and fully powered
>flight would not be characterized by useless random fluttering. Indeed, your
>second sentence may have answered the questions in your first sentence.

Certainly "useless random" fluttering would not happen.  But I think it is a
valid question to ask how the use of a power stroke evolved, and
non-useless, directed fluttering might have been involved.  As living
animals show an efficient glider can travel huge distances.  Why go to the
more energetically-expensive powered flight option?

I am only suggesting (hypothesizing, guessing) that this step would not have
been taken by an efficient glider trying to extend its range or degree of
control, but by a non-glider seeking to add a little more power to its
upward leaps.  Thus  an animal in a tree seeking to reach a limb (say) two
metres or so over its head could not glide to it, but could leap for it -
and a fluttering stroke may have given it a little more ability to
accomplish the leap successfully.  If this is true the evolution of powered
flight has nothing to do with gliding - indeed an accomplished flutterer
could add gliding to its repertoire later, rather than the other way round.
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