It may not have been well understood but it has been practiced for thousands of years. Darwin discusses it in Origin of Species.1) man selected seeds & animals to plant as the beginning of agriculture, but not always as well-thought out plans
not sure they understood genetics until Mendel, I don't think that people got serious until then (my opinion)
I was pointing that humans selectively breeding based on what they perceive to be superior traits is very different from natural selection. Therefore the Nazis were not applying evolutionary principals.2) that implies causality, I think that you may want to word it a little different, since "nature" in your statement is "active" & I think you meant to imply that its "blind" or "neutral" (am I reading to much into it?)