I used to believe to a degree in micro evolution, like that of bacteria, but I have come to the conclusion that the bacteria did not evolve anything. I think there is simply enough diversity in life that when man stomps on some form, like bacteria, that the bacteria with the genetic code being stomped simply declines allowing the growth of bacteria of a different genetic code to thrive.
There is a crab off the coast of china that is an example along the same lines of thought, where all the crab is eaten except that which appears to have the face of some long dead ruler on its shell so now crab is quite rare except that which has the face. But the crab did not evolve any more than bacteria, it just had a trait that allows it to thrive where others could not.