   In previous sections, we remarked on the difficulty of identifying the precise propensity that could, according to some, ground fitness ascriptions. Moreover, it is often difficult to isolate the populations where the evolutionary change is occurring. This is in part an operational problem, but for many biological systems, this difficulty may in fact reveal a deeper ontological issue. Thinking about fitness in reproductive terms depends on the possibility of identifying offspring (or successive replicators) and populations of them. For most Metazoans, this appears to be relatively straightforward. But how are we to treat the evolution of colonies, clonal organisms and symbionts (and hypothetically ecosystems)? Many philosophers have argued that our philosophy of biology’s usual bestiary does not reflect some of the complex organisation actually to be found in nature (J. Wilson 1999, D.S. Wilson and Sober 1989, Godfrey-Smith 2009, O’Malley and Dupré 2007, Bouchard and Huneman 2013) For many biological systems, organismal boundaries seem arbitrary ways to carve up the biological world. Those boundaries may merely reflect an impoverished way of thinking about biological individuality (Pradeu 2012, Haber 2013). Many biological individuals are in fact complex arrangements of other individuals. When these individuals belong to a single species (ex. some eusocial insects) a gene selectionist view according to which fitness is understood as the differential reproductive success of alleles may be available. But in the case of multi-species communities (e.g., fungus-termite colonies), allelic success will not track evolutionary change since some of the adaptations are not fully biotic (Bouchard 2009). Moreover, it has been argued (Turner 2004, Bouchard 2004, 2008) that some individuals that are adapting are not reproducing at all.