The foundress's dilemma: group selection for cooperation among queens of the harvester ant, Pogonomyrmex californicus

Authored by Marco A Janssen, Takao Sasaki, Zachary Shaffer, Brian Haney, Stephen C Pratt, Jennifer H Fewell

Date Published: 2016

DOI: 10.1038/srep29828

Sponsors: United States National Science Foundation (NSF)

Platforms: NetLogo

Model Documentation: Other Narrative Flow charts Mathematical description

Model Code URLs: https://www.comses.net/codebases/4262/releases/1.0.0/

Abstract

The evolution of cooperation is a fundamental problem in biology, especially for non-relatives, where indirect fitness benefits cannot counter within-group inequalities. Multilevel selection models show how cooperation can evolve if it generates a group-level advantage, even when cooperators are disadvantaged within their group. This allows the possibility of group selection, but few examples have been described in nature. Here we show that group selection can explain the evolution of cooperative nest founding in the harvester ant Pogonomyrmex californicus. Through most of this species' range, colonies are founded by single queens, but in some populations nests are instead founded by cooperative groups of unrelated queens. In mixed groups of cooperative and single-founding queens, we found that aggressive individuals had a survival advantage within their nest, but foundress groups with such non-cooperators died out more often than those with only cooperative members. An agent-based model shows that the between-group advantage of the cooperative phenotype drives it to fixation, despite its within-group disadvantage, but only when population density is high enough to make between-group competition intense. Field data show higher nest density in a population where cooperative founding is common, consistent with greater density driving the evolution of cooperative foundation through group selection.
Tags
social evolution Kin selection Division-of-labor Colony-level selection Apis-mellifera l Multilevel selection Pleometrotic advantage Pergandei hymenoptera Unrelated individuals Messor-pergandei