That’s a good question! In theory, yes, it would be possible to evolve the muscle power we’d need to jump really high. The question is whether we need to though – and that’s one of the main points of evolution. For something to evolve, it has to give us some sort of benefit over those that don’t have it. Being able to jump really high, while looking cool, would cost a lot of energy, and for no gain (we don’t need to jump high to get food, for instance). If we don’t really need to do something, there’s not much point in investing energy in it, because we could use that energy for more important things. As such, I don’t think we’ll see humans who can jump really high in the future. I might be wrong though!