Eusociality: origin and consequences

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 102; no. 38; pp. 13367 - 13371
• Main Authors: Wilson, E.O, Holldobler, B
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 20.09.2005; National Acad Sciences
• Subjects: altruism; Animal behavior; Animals; Ants; Biological Evolution; eusociality; Evolution; Formicidae; Group selection; Insect behavior; Insect castes; Insect colonies; Insect ecology; Insecta - physiology; Insects; Isoptera; Kin selection; natural selection; Perspective; Selection, Genetic; Social Behavior; Social insects; Worker insects
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0505858102

In this new assessment of the empirical evidence, an alternative to the standard model is proposed: group selection is the strong binding force in eusocial evolution; individual selection, the strong dissolutive force; and kin selection (narrowly defined), either a weak binding or weak dissolutive force, according to circumstance. Close kinship may be more a consequence of eusociality than a factor promoting its origin. A point of no return to the solitary state exists, as a rule when workers become anatomically differentiated. Eusociality has been rare in evolution, evidently due to the scarcity of environmental pressures adequate to tip the balance among countervailing forces in favor of group selection. Eusociality in ants and termites in the irreversible stage is the key to their ecological dominance and has (at least in ants) shaped some features of internal phylogeny. Their colonies are consistently superior to solitary and preeusocial competitors, due to the altruistic behavior among nestmates and their ability to organize coordinated action by pheromonal communication.