[Ruatha]

Originally posted by Mephisto:
The one problem "Natural selection" has as an evolution theory is how to explain how different species came to be.
Take birds for example: Evolution seems to be a slow and linear process. Most probably (but not necessarily) there wasn't a 4-legged-animal and the next breed had wings. So we need to have some steps in between the 4-legged-animal and a flying creature with wings. But now we have the problem why a creature, no more 4-legged but no bird either, is more fit to survive then the extreme ones (legged/flying). As far as I know we still have to find a fossil that shows us such a creature. Note, this does not say that "Natural Selection" isn't working or in effect. It just points out that it has a hard time to explain why, when you optimise your sun watch, you get a digital watch and not an optimised sun watch.

That isn't to hard to explain.
Take animals living in trees who are good to jump from tree to tree. For them the step to better gliding and eventually wings would be beneficial.