In many ways we funnel base biological instinct created from evolution within a social animal group into entirely into artificial constructs which allows us today to see all mankind as part of our social group regardless of genetic affiliation.
Class stratification is also not natural selection but the usage/abuse of our social system to offset it by making it irrelevant for people of higher class if they are capable or healthy since they managed to occupy a greater resource pool solely by merit of birth. So technically natural selection has been a non factor since the dawn of organized civilization.
The ultimate drive of natural selection is to safeguard oneself and one's descendants from its effects so the evolution of mankind to not be bound to it is a logical conclusion.
As for socialism. As usual monolithic application of a single ideology usually proves impractical. The golden/less disruptive path always seems to be a more moderate stance so while socialism as an end game has been rejected by the West, a lot of it's ideals has become mainstream goals for most people including right wing conservatives. Today it is rather radical to propose that we should let the poor starve in the streets, deny healthcare to people incapable to pay for it and the like and I would say most people would consider such radical positions asocial and immorale.
So the entire West has hybrid systems of capitalist market economies where the state intervenes into matters to guarantee basic living conditions for everyone.