 To understand this seemingly paradoxical situation, it is worthwhile to reflect on the nature of scientific concepts. Most, if not all scientific concepts are historically constituted, i.e., they are neither given once, with a unique and stable meaning attached to them and either remain in discourse unchanged or disappear entirely, nor are they merely subject of historical development in the sense of progressing towards some final, stable meaning. Instead, concepts are “in flux”; they change their meaning in the course of ongoing investigation (Elkana 1970). Additionally, when the investigative projects associated with a concept diversify, concepts may at any point in history exhibit several related but still different meanings in various local contexts. In each context, the concept might be more or less well defined, but overall, or at the boundaries between different fields of research, concepts will be perceived as rather vague (Löwy 1992). Furthermore, scientific concepts do not stand isolated; they belong to conceptual systems, discourses, and practices (Foucault 1971; Kuhn 1962; Lynch 1993). Indeed, what it means for a concept to change its meaning is that the context of use for a given concept or its relations to other concepts change. All of the above applies to the gene concept, which has been described as a “concept in flux” (Falk 1986), a fuzzy, vague, or boundary concept (Rheinberger 2000), and a “concept in tension” (Falk 2000), and studied as part of various discourses (Jacob 1970 [1973]; Keller 2000) or in the context of broader cultural spheres and practices (Müller-Wille &amp; Rheinberger 2012).