“Scientists inspired by Darwin and his eugenics theories.”
What eugenic theories?
Read Darwin's Origin of Species (it'd probably be banned if I posted the full title of his book). In it he noted things like that red ants used black ants as slaves and that, in his view, the red ant colony would cease to exist without the black ant slaves.
For those who couldn't piece together how his natural selection fit into keeping non-whites in their place, Darwin wrote a sequel to his book a decade or so later. In Descent of Man he gets really ugly about how whites evolved in a way superior to non-whites, how life is better off if the whites out-produce the non-whites, and that it can be best achieved by if whites keep non-whites too poor to survive and thrive (the argument being thriving leads to more babies).
Oh Darwin and Margaret Sanger go hand in hand