A New Set of Criteria for Units of Selection

This article proposes two conditions to assess whether an entity at a level of description is a unit of selection qua interactor. These two conditions make it possible to (1) distinguish biologically relevant entities from arbitrary ones and (2) distinguish units that can potentially enter a selection process from those that have already done so. I show that the classical approaches used in the literature on units and levels of selection do not fare well with respect to either or both of these desiderata.

Biological Theory, 17(4), pp. 263-275.