My work in philosophy of biology is focused mostly on the dysfunction of the concept and category species in evolutionary biology, and on evolutionary individuality.

In applied ethics I have worked and taught in environmental ethics; my work in bioethics is centered on organ markets, medical tourism, and more recently, on the intersection of medicine and ritual.

I have an interest in scientific classification, in the function of language in science, and in the emotional origins of ethical positions and reactions, and especially in repugnance.