Re: origin of bats/reply to J. Headden

[ptnorton <ptnorton@suscom-maine.net>]

> > When pre-bats became inverted bipeds their hands were no longer involved 
> > in locomotory matters. That freed the hands, as in pterosaurs and birds, 
> > to become something else. In the case of birds, foldable raptorial 
> > instruments and origins for flight feathers. In the case of pterosaurs, 
> > foldable display, flapping and gliding instruments.<<

I've lost track of who posted this statement, but it turns natural selection 
on its head to suggest that the flight feathers of birds and the "foldable" 
instruments (wings?) of birds and pterosaurs evolved because their hands had 
nothing else to do. As with other evolutionary innovations, flight feathers 
and flapping wings are the derived expression of innumerable steps in an 
undirected process that preferentially selected those random modifications 
of pre-existing characters that enhanced survival value. If at any point the 
hands of an animal became essentially irrelevant to survival (i.e., free "to 
become something else"), it is more likely they would be lost over time 
rather than being transformed into instruments for flight. The modifications 
that led to flight  in birds, bats and pterosaurs involved much more than 
just the function of the hands or the feet.

PTJN