Intraspecific competition and coordination in the evolution of lateralization

• Published in: Philosophical transactions of the Royal Society of London. Series B. Biological sciences Vol. 364; no. 1519; pp. 861 - 866
• Main Authors: Ghirlanda, Stefano, Frasnelli, Elisa, Vallortigara, Giorgio
• Format: Journal Article
• Language: English
• Published: London The Royal Society 12.04.2009
• Subjects: Animals; Asymmetry; Behavior - physiology; Behavior, Animal - physiology; Brain - physiology; Brain Evolution; Brain Lateralization; Evolutionarily Stable Strategy; Functional Laterality - physiology; Humans; Invertebrates - physiology; Laterality; Lateralization Of Behaviour; Models, Neurological; Psychology; Psykologi; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Socialvetenskap; Species Specificity; Vertebrates - physiology
• ISSN: 0962-8436; 1471-2970; 1471-2970
• DOI: 10.1098/rstb.2008.0227

Recent studies have revealed a variety of left-right asymmetries among vertebrates and invertebrates. In many species, left- and right-lateralized individuals coexist, but in unequal numbers ('population-level' lateralization). It has been argued that brain lateralization increases individual efficiency (e.g. avoiding unnecessary duplication of neural circuitry and reducing interference between functions), thus counteracting the ecological disadvantages of lateral biases in behaviour (making individual behaviour more predictable to other organisms). However, individual efficiency does not require a definite proportion of left- and right-lateralized individuals. Thus, such arguments do not explain population-level lateralization. We have previously shown that, in the context of prey-predator interactions, population-level lateralization can arise as an evolutionarily stable strategy when individually asymmetrical organisms must coordinate their behaviour with that of other asymmetrical organisms. Here, we extend our model showing that populations consisting of left- and right-lateralized individuals in unequal numbers can be evolutionarily stable, based solely on strategic factors arising from the balance between antagonistic (competitive) and synergistic (cooperative) interactions.