“For Charles Darwin and all who make evolution and natural selection central to their view of life, realism constantly tends to collapse into pessimism, whatever their individual protestations of joy and hope in life. And the reason is simple. Not only is natural selection utterly blind to evil and suffering, but it favors the “selfish gene” and the survivalistic ethic of “might makes right” that is the evil heart of oppression and abuse of power. No account of twentieth-century evil can ignore its close kinship to the dark side of Nietzsche’s will to power.” — Os Guinness, “Unspeakable: Facing Up to the Challenge of Evil” pg. 130
You can find the book here.