title: Group augmentation and the evolution of cooperation.
abstract: The group augmentation (GA) hypothesis states that if helpers in cooperatively breeding animals raise the reproductive success of the group, the benefits of living in a resulting larger group--improved survival or future reproductive success--favour the evolution of seemingly altruistic helping behaviour. The applicability of the GA hypothesis remains debatable, however, partly owing to the lack of a clear conceptual framework and a shortage of appropriate empirical studies. We conceptualise here the GA hypothesis and illustrate that benefits of GA can accrue via different evolutionary mechanisms that relate closely to well-supported general concepts of group living and cooperation. These benefits reflect several plausible explanations for the evolutionary maintenance of helping behaviour in cooperatively breeding animals.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich, UK; Behavioural Ecology and Self-Organization Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands; Max Planck Institute for Ornithology, Vogelwarte Radolfzell, Radolfzell, Germany. Electronic address: sjoukeannekingma@gmail.com.
authors.forename: Sjouke A
authors.initials: SA
authors.lastname: Kingma
authors.affiliation: Behavioural Ecology and Self-Organization Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands; Department of Zoology, University of Cambridge, Cambridge, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Santema
authors.affiliation: Department of Behavioral Ecology, Institute of Ecology and Evolution, University of Bern, Hinterkappelen, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Taborsky
authors.affiliation: Behavioural Ecology and Self-Organization Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Komdeur
mesh_terms: D001947:Breeding / Q000379:methods*; D003299:Cooperative Behavior; D006379:Helping Behavior
keywords: alloparental care; cooperation; group living; helping; mutualism; reciprocity; sociality