If you look back at the earlier years of the last century, some supporters of Darwinian evolution supported eugenics and other efforts to "improve the race." So did plenty of other people whose notions of humanity's origins were not derived from Darwin. After Hitler, most people rejected such ideas of eugenics, selective breeding, or the elimination of the "unfit." They saw clearly where such ideas could lead. That held for Darwinians, non-Darwinians, and anti-Darwinians.
Now we've come full circle. New techologies create new possibilities and some rush to embrace them. Some Darwinian evolutionists are in the lead, but they aren't the only ones. It will take some time to sort things out. It's doubtful that Darwinians will ever be won over to intelligent design. The question is whether we can adopt a moral consensus that can prevent dangerous policies from being put into effect. There are extreme Darwinians and extreme anti-evolutionists. Most people fit in somewhere in the middle, and are more concerned with doing the right thing in practice, rather than with asserting this or that vision of the universe.
Eugenics, in one form or another, has been around for a long time. It didn't start with Darwin.
Greek warrior Spartan civilization. Weakling infants were left in the mountains to die.
The Republic, Book 5, Section 1. Plato recommended state-supervised selective breeding of children.
History of Australia. Before Darwin, England exiled criminals to purify the race.