(chance @ Oct 19 2005, 04:23 PM)
The brain for animals that live in trees would have to develop before the partial gliding ability, itÃ¢â‚¬â„¢s already there in animals that leap between branches (binocular vision, good depth perception, superb balance, no fear of heights). Effectively itÃ¢â‚¬â„¢s already pre-adapted for gliding.
You know, that's a pretty brash statement, i.e. "something would have to be before, etc....".
I can't belive we've actually exceeded Chance's threshold of imagination.
Pre-adaptation is a common evolutionary theme (I did not just make it up), i.e. an adaptation in one environment suits a different environment not normally part of the animals experience. ThatÃ¢â‚¬â„¢s nothing different for an animal to develop dexterity in the fingers for tree living, then finding they are useful for carrying things, or you develop colour vision for choosing ripe fruit only to find you now have a better ability for seeing lions (unlike the grazing antelopes).
Why can't it be that the critters were just bad partial gliders, and managed to survive bouncing off the ground (that's what partial gliders do you know, i.e. bounce(real hard) from the heights of bushes, and then as they got smarter so their brains developed from all the bouncing(that's the environment shaping the genetics), and then as they learned how to fly., they moved up to greater heights.... Why not?????
Do you (did you) jump form a hight that you felt was too high? Of course not, you would have tested your abilities from a lower hight first as you played. Had you some feature or tool that increased your drag you would have felt that difference at the lower heights, the ability to jump, or glide to your body limits would be learned.
Partial gliding does not imply crashing at all, all it means is a translation to gliding distance, 10 meters, 15 meters, 30 meters. Just because I used the term poor is no reflection on the animals skill, it only a reflection relative to a better glider or flyer. If we wanted to get pedantic about it the evolutionary stages, we should drop all references to poor, better, fantastic, and convert it do distance, i.e.
Jumping Ã¢â‚¬â€œ no assistance, 5 to 10 meters
First skin flap mutation 6 to 11 meters
Additional skin, 7 to 12 meters
beginning of powered flight
50 to 100 meters
1 klm 50 klm
At no stage is the animal in question considered poor at anything itÃ¢â‚¬â„¢s just able to cover x amount of ground.