The problem is that the "original version" and not a perversion of it, is what led to eugenics. The notion that any variation is inheritable (Darwin) is precisely that notion which makes pathological science like eugenics and evolutionary psychology possible. Despite Mendel and all the advances in genetics, Darwinians still think in terms of Darwinian heredity, even today.
What the F is "Darwinian heredity?"
Even today, even?
So you say. Prove it.
The eugenics movement is a gross perversion of Darwin.