 The intense philosophical interest in evolutionary theory in the 1980’s can partly be explained by two controversies (Segerstråle 2000). First, there was a controversy over “sociobiology” that was provoked by the publications of E.O. Wilson’s eponymous textbook (Wilson 1975) and his Pulitzer prize winning popular book (Wilson 1978). One extremely important critique of this application of evolutionary biology to human social behavior came from Stephen Jay Gould and Richard Lewontin (Gould and Lewontin 1979). The debates over adaptationism turned out to involve a diffuse set of worries about whether evolution produces adaptations, the role of optimality models, and the methodology of evolutionary theory (Amundson 1994; Orzack and Sober 1994; Brandon and Rausher 1996; Godfrey-Smith 2001; Millstein 2007; Forber 2009; Potochnik 2009; Lloyd 2015). Philosophical work has helped to distinguish these strands in the debate and reduce the confusion seen in the heated and polemical biological literature for and against adaptationism (Orzack and Sober 2001). Second, there was the appearance of George Williams’ Adaptation and Natural Selection (Williams 1966) and Richard Dawkins’ The Selfish Gene (Dawkins 1976). They claim that the unit of selection is the individual Mendelian allele rather than the organism, group of organisms, or species. This created an explosion of early philosophical work on the “units of selection” question (Brandon and Burian 1984). The early debates concerned whether there was a determinate unit of selection and what criteria should be used for determining what it is in a given case (Hull 1980; Wimsatt 1980a, 1980b; Brandon 1982; Sober &amp; Lewontin 1984; Lloyd 1988; Sterelny &amp; Kitcher 1988). As multi-level selection models and the Price equation appeared, close attention turned to how those models should be interpreted (Godfrey-Smith &amp; Lewontin 1993; Godfrey-Smith &amp; Kerr 2002; Lloyd 2005; Waters 2005; Okasha 2006; Birch 2017). For example, for any group selection model, is there an empirically equivalent individual selection model (similarly for genotypic and genic models)? If so, do they represent the very same causal structure? Is kin selection a form of group selection? Arguably, philosophers made a significant contribution to the rehabilitation of some forms of “group selection” within evolutionary biology in the 1990s, following two decades of neglect or contempt (Sober and Wilson 1998).