Nietzsche's investigation into the origins of morality bears some striking similarities to contemporary investigations into human evolution. Here I investigate these similarities, using a comparison between Nietzsche's GM and Gould and Lewontin's influential “Spandrels” essay as a departure point. I argue that Nietzsche defends a proto-evolutionary psychology about morality, where the inheritance of enduring biological drives conflicts with our culturally evolved moral system. While Nietzsche's claims about the evolution of morality fit well within a Darwinian framework of natural selection, his claims about our underlying biology do not. Those claims cohere better with the non-Darwinian views found in nineteenth-century German biology and embryology.