Could I force the hand of evolution?

Most important consideration: flapping your arms, and teaching your children to flap their arms, and their children to flap their arms, etc, for a hundred generations won't change your genetic makeup, and THIS is what evolution is based on. Acquired traits aren't ped on (despite Lamarckian Theory). IF humans sprout wings, it's not because they want to- evolution has no goal (except, maybe, adaptation). Evolution (which you might call "Nature") modifies what arises by chance, and this modification is brought about by a mechanism called Natural Selection; Nature does not "invent" traits.