An outstanding problem in biology is whether natural selection acts at levels other than that of individual organisms. Selection acting on group characteristics may be important but the biological processes that give rise to it are poorly understood. Behavioral decision-making, in which animals discriminate among alternatives using group as well as individual properties, is a source of group selection that has never been formally investigated. The proposed research will develop and analyze models of group selection caused by three common types of behavioral decision-making: (1) choice of flowers by insect pollinators; (2) female mate-choice, and (3) host choice by plant-feeding insects. Detailed formulations of decision-making behavior will be combined with quantitative genetic models in order to link the observable properties of animal behaviors to their short-and long-term evolutionary consequences. This will provide the first analysis of a potentially-important form of group selection. The results will identify those situations in which group-level selection can be expected and will yield predictions that can be tested in natural populations.
