Mike writes:
What if a species needs wings tomorrow, and the change will take place in M.O.Y only. Won't that species simply go extinct?
That's exactly what it'll do - die out. That's why so many species are going extinct right now - we humans can change whole biomes way faster than most natural processes can. And I've seen the estimate that over 99% of ALL species that have ever existed are already extinct.
We can easily imagine that any "early ape-man" that travelled out to the treeless veldt sure enough became cheetah bait. But his cousins that stayed near the water holes, and let the savannah come to them over a thousand generations as the African climate dried out - they fared a little better. Yeah, evolution takes a long time. But just we mammal-like critters have had 250,000,000 years. That is a long time.