Evolution is a fact.
_________________________
Which aspect is a fact?
The fact that nothing on earth is a perfect replicator (mutation creates genetic diversity) and that natural selection acts on variation by increasing or decreasing the incidence of this variation based upon the relative advantage or disadvantage it confers.
Evolution happens every time. There is in fact no way to stop it.
Take a single bacteria and plate it and grow up a colony from that one specimen. Now plate that colony on 10 different plates and subject them to 10 different selective pressures (heat, cold, antibiotics, etc) and you will find that variation that did not exist within the original specimen is present in these selected colonies, and that these variations tend to allow for living in these adverse conditions. It happens every time.