Oh the irony, to use evolution as an argument to approve of genetic engineering or eugenics. The grand scheme of improving mankind!!!
Evolution of course does not strive to improve anything or to progress. It is a process that is based on the need to be adapted to a certain environment. We are quite well adapted to our current environment. Hence we do not have to progress. And we certainly do not need excuses such as that it is a natural process.
Just state the real reason, whatever it might be, but don't drag evolution in to it.