This article introduces a collection of studies of biological concepts crossing over to other disciplines and nonscholarly discourses. The introduction discusses the notion of nomadic concepts as introduced by Isabelle Stengers and explores its usability for conceptual history. Compared to traveling and interdisciplinary concepts, the idea of nomadism shifts the attention from concepts themselves toward the mobility of a concept and its effects. The metaphor of nomadism, as outlined in the introduction, helps also to question the relation between concepts' movement (...) and the production of boundaries. In this way conceptual history can profit from interaction with translation studies, where similar processes were recently discussed under the notion of cultural translation. (shrink)