 In this context, Alan Love (2005, 2008, 2014) uses the notion of a problem agenda to argue that some scientific problems not only motivate interdisciplinary research but also provide structure for the requisite intellectual coordination (see also Brigandt 2010, 2012, Brigandt and Love 2012). Problem agendas consist of numerous component questions that stand in systematic relations and are tied to associated standards of explanatory adequacy. These standards imply what epistemic resources and different disciplines are needed to address the problem. The relations among component questions of the problem agenda (i.e., its internal structure) foreshadow how various contributions can be coordinated to generate an adequate explanatory framework. Building on this perspective, Ingo Brigandt (2010) suggests that there is no single, linear hierarchy among scientific fields (e.g., Oppenheim and Putnam 1958; see Hüttemann and Love 2016), but that the relationships among theories and disciplinary approaches are determined by and vary with the scientific problem being addressed. These philosophical accounts align with general research on interdisciplinarity, which has identified the presence and articulation of a complex question as a prerequisite (Repko 2008, Szostak 2002, 2009). Thus, instead of unification being a regulative ideal with biologists seeking as much unity as possible in their explanations of the complex natural world (e.g., Kitcher 1999b), an erotetic perspective suggests that particular problems determine the need for and degree of any integration (Brigandt 2010). William Bechtel’s (1993, 2006) studies of cell biology document how the formation of new subdisciplines generates both integration among approaches and some disintegration due to new specializations. Bechtel’s attention to the institutional underpinnings of biology also meshes with sociological analyses of disciplinary organization (Gerson 1998, 2013).