Nothing in your post indicates that you understand science.
A bit of technology, yes, but not science.
Oh, yes, and how do you thing variations occur in populations?
Take moths for instance, within a population some were lighter and some were darker. When the trees were lighter the lighter ones blended in better, and the birds ate the darker ones. When the trees became darker the lighter moths were easy pickings. The population in this case shifted from predominately being lighter to being darker. Over time the variation in the population was noted. In this case the change in the population occurred because the birds ate more of one shade of the moths and the darker ones were more likely to reproduce.