Promiscuity and the evolutionary transition to complex societies.
Theory predicts that the evolution of cooperative behaviour is favoured by low levels of promiscuity leading to high within-group relatedness. However, in vertebrates, cooperation often occurs between non-relatives and promiscuity rates are among the highest recorded. Here we resolve this apparent inconsistency with a phylogenetic analysis of 267 bird species, demonstrating that cooperative breeding is associated with low promiscuity; that in cooperative species, helping is more common when promiscuity is low; and that intermediate levels of promiscuity favour kin discrimination. Overall, these results suggest that promiscuity is a unifying feature across taxa in explaining transitions to and from cooperative societies.
Cornwallis
Charlie K
CK
Edward Grey Institute, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.
West
Stuart A
SA
Davis
Katie E
KE
Griffin
Ashleigh S
AS
D000818:Animals; D005075:Biological Evolution; D001717:Birds / Q000145:classification / Q000235:genetics / Q000502:physiology*; D003299:Cooperative Behavior; D005220:Fathers; D005260:Female; D008297:Male; D008954:Models, Biological; D009035:Mothers; D010802:Phylogeny; D012098:Reproduction / Q000235:genetics / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000502:physiology*; D035781:Siblings