The problem my doctoral research focuses on is the discord between communities of historians of biology, philosophers of biology, and practicing biologists in interpretation, use and evaluation of the distinction between ‘typological thinking’ and ‘population thinking’. In the years since biologist Ernst Mayr introduced this dichotomous distinction, it has spread through textbooks, articles and anthologies in different disciplines. Some take the distinction to be no more than a rhetorical device, others think it brings out fundamental metaphysical and/or epistemological differences that are relevant from a historical perspective or in contemporary scientific practice. The widely divergent interpretations of the meaning and relevance of the distinction come together in the philosophy of biology. There the distinction is invoked in a variety of discussions on conceptual issues in evolutionary biology, without there being much uniformity in its interpretation and deployment. To mitigate polysemy within the philosophy of biology and to promote communication between historians, philosophers and evolutionary biologists it is important to put the distinction on a firm footing. Reassessing and continuing recent work in the history and philosophy of biology will help to acquire a better understanding of what the distinction between typological and population thinking is a distinction between, what its relation is to other long-standing conceptual issues, and what its relevance is to topical issues in evolutionary developmental biology and systematics.