Models of parent–offspring conflict: effect of environmental variance

Abstract

"Parent-offspring conflict" is a theoretical concept proposing that siblings are selected to be slightly more greedy with each other than parents are selected to tolerate. This paper extends a class of previous models of parent–offspring conflict by introducing a new and more realistic dimension to the analysis: the amount of investment an offspring receives is influenced by non-genetic causes (environmental variance) as well as genetic causes. Results of previous models are substantiated for a wide range of conditions, with two interesting results: (1) direct testing of these models of parent–offspring conflict will prove harder than previously supposed, and (2) in some cases the conflict disappears. The models identify several difficulties that confront quantitative, empirical studies of parent–offspring conflict, and they may consequently help anticipate those aspects of parent-offspring conflict that are most amenable to study.