So you say. Prove it.
The eugenics movement is a gross perversion of Darwin.
Sometimes you hear people say that eugenics is a pseudo-science. Other times, people say that it can work in principle, but it is unethical or immoral. Still others say that the issue should be re-opened: that in principle eugenics is a correct idea and is not necessarily immoral. Such is the view of Dawkins, for example, and a few others today. This view presupposes that eugenics works. Which view is correct? The fact is, eugenics rests on a mistaken notion of heredity, so it cannot work. Mendelism and the Hardy-Weinberg rule is sufficient to refute eugenics. To refute the assertion that prostitution can be eliminated via eugenics, it suffices to ask where, in the genes, is prostitution. No answer will be forthcoming. No, the poor, the chronically unemployed, and the prostitutes cannot "limit their numbers" (as eugenists like to say) by contraception and sterilization, for two reasons: (1) these traits (or variations) are not genetic, and (2) the Hardy-Weinberg rule. See Spencer's 2001 article Did Eugenics rest on an Elementary Mistake? And so eugenics is a fake science. But why is it plausible? It must have some plausibility, since so many prominent Darwinians were also prominent eugenists. What does eugenics rest on?
Darwin believed that any variation he liked was heredible. This is a historic fact; I am surprised that you don't know about it. Darwin made no distinction between somatic and germinal variations. Every adaptation arising from natural selection presupposes germinal inheritability. That includes the bear's ever-widening mouth, human morality, and even the character of American people (e.g., Descent of Man ch. 5.)
Darwin's notion of heredity was developed further by Galton, then Fischer and Pearson. All of whom were eugenists. This line of thinking became the so-called Biometric school of heredity. But early on in this history, something happened to disturb their progress: Mendel. Mendelism refutes this entire line of thought, from Darwin to Pearson. Because of this, Mendel was ignored, and then he was "outed" as a fraud by Fischer, and Pearson never accepted Mendelism. But Mendelism would not go away, and Darwinians had to deal with it: hence the Modern Synthesis.
Julian Huxley was one of the architects of the modern synthesis. He was also the world leader of the eugenics movment. Despite the modern synthesis, despite Mendel and all the advances in genetics, he, and many others, merely continued with Darwin's original model of heredity: anything you like is heredible. Prostitution, poverty, immorality, chronic unemployment, feeble-mindedness, genius, intelligence, whatever. It doesn't matter if there are no genetic factors that correspond to these variations, the eugenist says they can be eliminated by selection, and therefore, they must correspond to something in the genes regardless of evidence and regardless of the Hardy-Weinberg rule. Needless to say, sociobiologists and evolutionary psychologists make exactly the same sort of presupposition when they write evolutionary fairytales about monogamy, adoption, why men prefer blondes, cathedral building, cannibalism, and so on.
And so, it is not that eugenics is a gross perversion of Darwinism, but rather, that eugenics rests on Darwinism's gross perversion of heredity.