We hardly won't.
Evolution is very simple, those fit to survive end up surviving and pass on their genes, those who don't perish before doing so.
Theres no big guiding hand choosing which genes would be most fit for passing on, and which are not usefull anymore, hence we won't loose our pinky toe, or our appendix, unless having those stops us from pro-creating.
The only thing that we can evolve past, is things stopping us from pro-creating, mainly sterility, and only the kinds of sterility serious enough, that they can't be helped medically.
On the other hand, you could argue that we're actually devolving, since people who would've not survived to pass on their genes years ago, can survive and pass on their genes today, due to science.
If controlled breeding was enforced, we could evolve more, or if science finds some way to controll which genes are beeing passed down to the child of 2 given people.
But yeah, science is taking over for evolution, providing the solutions to our problems, evolution would've otherwise provided in a much crueler way.