 An important research goal is to provide a model for the fundamental features that distinguish living systems from the non-living. So far, however, there is no consensus on the defining features of life. Whether this should be seen as a disappointment, indicating the uselessness of attempts to define life, is an ongoing issue of philosophical debate. Different views on this question may depend on different interpretations of what the project of defining life entails in philosophy and science, e.g., whether the aim is to establish demarcate a natural kind (Cleland 2012) or to provide operational definitions of practical use in model and theory construction (Bich &amp; Green 2018; Luisi 1998). More specific topics of debate are whether definitions of life must include Darwinian evolution, how evolution and units of selection should be defined, and whether it is fruitful to categorize all the varieties of life forms under one definition (Dupré &amp; O’Malley 2009; Laland et al. 2009; Ruiz-Mirazo et al. 2010; Szostak et al. 2001)