“With the little changes that happen with reproduction, the configuration of your DNA and your genes can change for you and others in the population of your kind. This is called “genetic drift.” If the genes drift a little at the same time that there’s a change in the environment, the drifted genes may be the only ones that make it through. This is an example of microevolution—a change in the genetic mix within a species or population. You can think of it simply as evolution by small changes over short times.”