One thread at a time please. If you really want something from me here, then let me give you what came off the top of my mind.
How does the squirrel or the glider (a marsupial?) develop the very first stages of flight before they actually fly? What spurs the initial stages of this development? I'm sure neo-Darwinism has an answer for it. I think hopping from branch to branch would account for it. But what types of random mutaions would account commence the thin membranes to form? I would think Lamarckism would be a more plausible explanation.