Experimental philosophy of science gathers empirical data on how key scientific concepts are understood by particular scientific communities. In this paper we briefly describe two recent studies in experimental philosophy of biology, one investigating the concept of the gene, the other the concept of innateness. The use of experimental methods reveals facts about these concepts that would not be accessible using the traditional method of intuitions about possible cases. It also contributes to the study of conceptual change in science, which we understand as the result of a form of conceptual ecology, in which concepts become adapted to specific epistemic niches.