Oecophylla brain and body mass data, brain volume data, and cytochrome oxidase activity data from Kamhi JF, Gronenberg W, Robson SKA, Traniello JFA (2016) Social complexity influences brain investment and neural operation costs in ants.
Extract from Abstract [Related Publication]: The metabolic expense of producing and operating neural tissue required for adaptive behaviour is considered a significant selective force in brain evolution. In primates, brain size correlates positively with group size, presumably owing to the greater cognitive demands of complex social relationships in large societies. Social complexity in eusocial insects is also associated with large groups, as well as collective intelligence and division of labour among sterile workers. However, superorganism phenotypes may lower cognitive demands on behaviourally specialized workers resulting in selection for decreased brain size and/or energetic costs of brain metabolism. To test this hypothesis, we compared brain investment patterns and cytochrome oxidase (COX) activity, a proxy for ATP usage, in two ant species contrasting in social organization.
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