I have never delved into it, but I have always considered changing environments as the obvious reason for "natural selection" leading to evolution. So I'm not sure if there is a difference between the results of natural selection or evolution.
The microbial world gives us an opportunity to witness some of what occurs.
It is hard to comprehend the time frames it takes for us to be who we are.
Evolution is a fascinating subject, but not one I have been able to put much/any time into.
