Re: origin of bats/reply 2 to TMK

[Erik Boehm <erikboehm07@yahoo.com>]

While the presence of what appear to be wings does not prove they were used for 
flight, it is the best explanation.

The presence of limbs on early tetrapods certaintly don't prove they were used 
for walking on land, despite that being the initial assumption -with later 
fossils showing tetrapods clearly evolved limbs not meant for walking on land. 

Yet no one doubts they did function as limbs, albeit not limbs meant to bear a 
lot of weight.

The wings just appear too suitable for use as an aerodynamic lift generating 
surface to me, to not be adaptations for something that requires such a surface.

Aside from gliding or flying, what use is a lift generating surface?
Assist in agility on the ground like a spoiler on a car?

What else could the surface be(if not a lift generating one)?
"Insect traps"? is there any discription of the cross section of the wing? 
unless it is not asymetrical, it would seem to be adapted for generation lift, 
it seems extending such wings would blow the insect away, unless the opposite 
strategy were used, holding the wings in front and rapidly parting them to suck 
in the bug, similar to how fish suck in their prey when they open their mouth - 
but this should lead to an "inverted wing" and would thus make a transition to 
flight rather hard- I don't buy the insect trap explanation.

The simplest explanation that fits all the facts seems to be they are meant to 
generate aerodynamic lift. The simplest explanation for having that ability, is 
gliding.