 Population genetics is an important branch of science, but why should philosophers care about it? There are a number of reasons. Firstly, Darwinian evolution has long been a fruitful source of ideas for philosophers working in a variety of areas, including philosophy of mind, ethics and political philosophy. (Recall Darwin’s famous comment “he who understands baboon would do more for metaphysics than Locke”). To properly understand evolution requires a grasp of basic population genetics, which provides one motivation for philosophers to learn about this field. Secondly, population genetics is a possible “testing ground” for ideas developed in general philosophy of science about idealization, explanation, the role of abstract models, and the interplay between theory and data. Thirdly, population genetics features prominently in many debates in philosophy of biology over issues including the nature of evolutionary causation, the logic of selective explanation, the role of chance in evolution, and the relation between population-level and individual-level processes. Finally, population genetics is indirectly relevant to certain other philosophical debates, such as the debate over the reality of biological race, for example.