Humans have never stopped evolving and continue to do so today. Evolution is a slow process that takes many generations of reproduction to become evident. Because humans take so long to reproduce, it takes hundreds to thousands of years for changes in humans to become evident. We simply don't notice the evolution of humans from day to day because it is happening so slowly. But creatures that reproduce more quickly also evolve more quickly. For instance, bacteria can reproduce within 20 minutes, so their evolution can be watched by scientists over the course of a few days. All creatures are always evolving. There is no way to stop evolution.