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. © 1985 The Genetical Society of Great Britain.