-For evolution: The "cavemen." In other words the Danisovans. (They seemed to have evolved from monkey like life styles, to standing and walking.)
-Fossils show us, by piecing them together, that evolution occurred (possibly) by how the Danisovans would crawl, stand, and walk.
-(I do not know how many bones are in a bat wing. Assuming that they both are about the same, it shows that no matter how big or small something is, it may have a complicated bone structure.)
-This one you can think of on your own, I will give you an idea of what you would observe, though...
(You would observe the bones, the hairs, skin, the way each limb works, etcetera.)
I hope this helps! (:
