I think for as long as an inferior peoples exist, the superior will eventually dilute and fade out, as the inferior are more plentiful than the superior, see current world distributions for instance. We can see this in India, Rhodesia, and Rome for instance. And even GOD supports eugenics (see noahs ark). And the fact that we do have free will to let animals go extinct is a testament to our God gifted free will, do you think God wept when the dodo went extinct? Even if it does temporarily hurt the ecosystem there is always an invisiblee hand who gradually corrects the ebbs and flows and brings about equilibrium. "To God everything is beautiful, good, and just; humans, however, think some things are unjust and others just." - Heraclitus.
