I think evolution happens quite fast. The human genome is now a lot more advanced than it was 30,000 years ago at time of the cave paintings. At that time the average life span was 18 years, while its now 70 years.

This is not alone explained by advances of medicine. We also are healthier than our ancestors because healthiness is a selection factor in evolution. Skeletons found of cave people show that they often suffered from diseases, like deformities, that are much less frequent today. Improvements to the human genome are proven, for example the famous Milano mutation that happened some 150 years ago in a small village near Milano. People with that mutation live longer and don't get heart diseases.

This is evolution at work. I learned in biology that every person has about 2 mutation in his genome so we all are mutants!