If these people pass the changes on to their descendants, how can you deny a genetic change?
And this is what evolution is, a change in the genomes of a population from one generation to the next. Evidence for these changes is everywhere.
Then add a few thousand, hundred thousand, or million years, stir well, and presto: macroevolution!
Its not rocket science!
Coyoteman, an example of genetic evolution is the change of a species into another completely different species. I.E. Cromagon Man evolving into Homo Sapien. What you are attributing to genetic variety cannot be attributed to evolution. Now, to expand on this, those samples of a species that, due to the benefit of variety, develop a superior genetic makeup may eventual evolve into a new species. But in the case of Humans this has not been proven.