The Darwinian Dilemma

Here are two articles by Sharon Street which make the case that naturalistic evolution undermines moral realism:

Go to her academic page for downloadable versions:

https://files.nyu.edu/jrs477/public/streetpapers.html

1. "A Darwinian Dilemma for Realist Theories of Value," Philosophical Studies 127, no. 1 (January 2006):  109-166.
2.  "Reply to Copp:  Naturalism, Normativity, and the Varieties of Realism Worth Worrying About," Philosophical Issues (a supplement to Noûs), vol. 18 on "Interdisciplinary Core Philosophy," ed. Walter Sinnott-Armstrong, 2008.