inclusive fitness

Nowak MA, Tarnita CE & Wilson EO 2011 Nowak et al. reply. Nature 471:E9-E10.

• the concept of inclusive fitness assumes that the fitness of individuals can be split into additive components caused by individual actions
• we distinguish between inclusive fitness theory and standard natural selection theory, because the latter does not require fitness to be split into additive components
• there are attempts to make Hamilton's rule work by choosing generalized cost and benefit parameters
• these parameters are no longer properties of individual phenotypes
• they depend on the entire system including population structure
• these extended versions of Hamilton's rule have no explanatory power for theory or experiment
• neither inclusive fitness theory nor any formulation of Hamilton's rule can deal with evolutionary dynamics
• this fact alone invalidates the claim that inclusive fitness theory "is as general as the genetical theory of natural selection"

• we do not argue that relatedness is unimportant
• relatedness is an aspect of population structure

• we do not know of a single study where an exact inclusive fitness calculation was performed for an animal population and where the results of this calculation were empirically evaluated
• fitting data to generalized versions of Hamilton's rule is not a test of inclusive fitness theory