Multilevel selection and social evolution of insect societies

Area of Science:

• Evolutionary biology
• Behavioral ecology
• Social evolution

Background:

• Social insects, particularly haplodiploid bees, ants, and wasps, are key models for understanding social evolution and conflict resolution.
• Kin selection theory has been central to explaining altruistic worker castes, but insect societies show robustness against variations in relatedness.

Purpose of the Study:

• To investigate the evolutionary maintenance of sterile worker castes in social insects.
• To explain the discrepancy between kin structure predictions and empirical data on insect societies.
• To explore the role of constraints and multilevel selection in resolving within-group conflicts.

Main Methods:

• Application of a multilevel selection approach.
• Analysis of conflict resolution mechanisms in insect societies.
• Comparison with conflict resolution at other biological levels (genome, multicellular organisms).

Main Results:

• Constraints like lack of power or information act as group-level adaptations preventing or resolving intracolonial conflict.
• Mechanisms of conflict resolution include alignment of interests, fair lottery, and social control.
• Insect societies demonstrate remarkable robustness against variations in nestmate relatedness.

Conclusions:

• Relatedness is less critical for the *maintenance* of insect societies than previously thought, though fundamental to their *evolution*.
• Insect societies represent a distinct level of selection, offering benefits beyond solitary life.
• Group-level adaptations and conflict resolution are key to the stability and success of social insect colonies.