 Philosophers and scientists often invoke the word emergent for phenomena that are different from the phenomena generated by their components (see the entry on  emergent properties).  Sometimes emergent phenomena are viewed as incapable of being explained in terms of their constituents. In the context of characterizing systems biological accounts of cell phenomena, Boogerd et al. (2005) develop an account according to which emergent phenomena are ones that are fully explicable in terms of how their constituents behave in the organized system, but not in terms of how they behave in simpler (less complexly organized) systems. This recognizes that many cellular constituents behave differently when incorporated into particular systems in which they receive distinctive inputs. For other recent treatments of emergence and its applications to cell biology, see (Hooker 2011a; S. Mitchell 2012; Mossio, Bich, &amp; Moreno 2013; Winning &amp; Bechtel 2019).