De-Evolution is not existing. Someone had to pick the bad ones to survive. How should that happen? Maybe a wrong social policy of a government could have a small influence?

But I am sure that evolution can be slowed down or even stopped. We don't have a selection anymore. A very smart or very strong human will not have a big advantage over weak, ill or dumb people at the moment. So our evolution could have come to an end.

The greatest speed of evolution happens in situations where a species needs every small advantage to survive. The weak individuums extinct and the strong survive. All that will not happen with humans anymore.
So we will not become any kind of alien race in the future