title: Promiscuity drives self-referent kin recognition.
abstract: Kin selection theory has been one of the most significant advances in our understanding of social behavior . However, the discovery of widespread promiscuity has challenged the evolutionary importance of kin selection because it reduces the benefit associated with helping nestmates . This challenge would be resolved if promiscuous species evolved a self-referent kin-recognition mechanism that enables individuals to differentiate kin and nonkin . Here, we take advantage of an asymmetry in the level of promiscuity among males of alternative life histories in the bluegill sunfish (Lepomis macrochirus). We show that, as a consequence of this asymmetry, offspring of "parental" males have a high level of relatedness to nestmates, whereas offspring of "cuckolder" males have a low level of relatedness to nestmates. We find that offspring of parentals do not use a direct recognition mechanism to discriminate among nestmates, whereas offspring of cuckolders use kin recognition by self-referent phenotype matching to differentiate between kin and nonkin. Furthermore, we estimate that the cost of utilizing such self-referent kin recognition is equivalent to a relatedness (R) of at least 0.06. These results provide compelling evidence for adaptive use of kin recognition by self-referent phenotype matching and confirm the importance of kinship in social behavior.
authors.affiliation: Department of Biology, University of Western Ontario, London, Ontario N6A 5B7, Canada.
authors.forename: Timothy J A
authors.initials: TJ
authors.lastname: Hain
authors.forename: Bryan D
authors.initials: BD
authors.lastname: Neff
mesh_terms: D000818:Animals; D003463:Cues; D005307:Fertilization in Vitro; D007814:Larva / Q000235:genetics / Q000502:physiology; D008297:Male; D009812:Odorants; D010473:Perciformes / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D012726:Sexual Behavior, Animal; D012919:Social Behavior