So, you say that anyone whose DNA is different from "the norm" can't reproduce, so all humans have identical DNA eh? Get real.
You are FOS (that does compute easily). All species have genetic variation and that variation is then available to be acted up on by selection and drift and that means evolution happens. You can't stop it. It is inevitable. That is exactly why you are FOS. This really isn't hard to understand you know. You need to find us a mechanism that prevents variation or at least keeps the variation invariant. And that just doesn't exist because they DO reproduce.
PS. Horses and donks are two different species. Restrict your answer to that which is within a species and then we will get to the horses and donks because they come next.
