Evolution works by natural selection, which implies extermination of competing varieties.
But once that factual picture gets into people's heads, a fiercely racist eugenics might be predicted to emerge, as in fact it did. This time I call Val Dusek to my defense. One can assume any counterfactual for sake of argument. But Darwinian science, the state of the art in its day, has regularly furnished grounds for racist social policies. I take it to be fundamental to Darwinian thinking that nature is not governed by some moral higher power.