We have stopped natural selection from purifying the species because deep in our heart of hearts, we are all terrified that we won't make the cut.

...their hearts had still not been hardened with the inevitable cynicism that familiarity and experience breed. 

Natural selection is anything but random.

Natural selection eliminates and maybe maintains, but it doesn't create.

Ideas percolate. Through natural selection, the best ones survive.

But the very fact that Darwinism is true makes it even more important for us to fight against the naturally selfish and exploitative tendencies of nature.We can do it.Probably no other species of animal or plant can. We can do it because our brains (admittedly given to us by natural selection for reasons pf short-term Darwinian gain) are big enough to see into the future and plot long-term consequences.