How does social complexity shapes the brain structure and function?
The Social Brain Hypothesis, originally developed for primates, posits that larger groups require bigger brains to adaptively process social information, while the Expensive Tissue Hypothesis informs of the cost of producing bigger brains.
Insects are small-bodied and their brains have likely evolved under restrictions of miniaturization. Social insects—ants, bees and wasps—have miniaturized brains that nevertheless support striking individual cognitive abilities such as compass orientation, complex learning, and face recognition. Accordingly to the Social Brain Hypothesis, these characteristics should lead to an increase in brain size. By the other hand, social insects are renowned for their remarkable collective intelligence and division of labor. This distributed processing of information might relax the cognitive challenges of individual workers, leading to the opposite prediction: a reduction in brain investment.
Humans, like ants, form “ultrasocial” societies characterized division of labor and collective intelligence. However it is difficult to examine in humans how social life influenced brain evolution: we are a single species and historical analyses are limited to comparison of cranial capacity of fossil forms. Ants, in contrast, are a species-rich clade that shows broad variation in social complexity and body size. Studying the ant brains can help identify general principles related to the neurobiology of social animals, including us. Additionally, miniaturized brains can inform us about evolutionary trade-offs, more efficient ways to solve problems or the minimal neuroarchitectures needed to support social behavior.
The overall objectives of this project are to understand the relationship between brain region investment, metabolic costs and individual cognitive abilities of ant workers under different conditions of sociality. We examine the effect of distributed information processing in the form of degree of collective foraging, subcaste polymorphism or colony size on the neurobiological, cognitive and behavioral characteristics of ant workers and also on the energetic investment in specialized brain compartments that underlie behavior. We combine techniques applied to the study of collective animal behavior (natural history, ethology, individual tracking and learning experiments) with neurobiology methodologies (immunohistochemical imaging and high performance liquid chromatography) in ant species varying in social complexity. This novel and integrated approach will allow us to analyze the evolutionary relationship between social complexity and brain evolution.
The Social Brain Hypothesis, originally developed for primates, posits that larger groups require bigger brains to adaptively process social information, while the Expensive Tissue Hypothesis informs of the cost of producing bigger brains.
Insects are small-bodied and their brains have likely evolved under restrictions of miniaturization. Social insects—ants, bees and wasps—have miniaturized brains that nevertheless support striking individual cognitive abilities such as compass orientation, complex learning, and face recognition. Accordingly to the Social Brain Hypothesis, these characteristics should lead to an increase in brain size. By the other hand, social insects are renowned for their remarkable collective intelligence and division of labor. This distributed processing of information might relax the cognitive challenges of individual workers, leading to the opposite prediction: a reduction in brain investment.
Humans, like ants, form “ultrasocial” societies characterized division of labor and collective intelligence. However it is difficult to examine in humans how social life influenced brain evolution: we are a single species and historical analyses are limited to comparison of cranial capacity of fossil forms. Ants, in contrast, are a species-rich clade that shows broad variation in social complexity and body size. Studying the ant brains can help identify general principles related to the neurobiology of social animals, including us. Additionally, miniaturized brains can inform us about evolutionary trade-offs, more efficient ways to solve problems or the minimal neuroarchitectures needed to support social behavior.
The overall objectives of this project are to understand the relationship between brain region investment, metabolic costs and individual cognitive abilities of ant workers under different conditions of sociality. We examine the effect of distributed information processing in the form of degree of collective foraging, subcaste polymorphism or colony size on the neurobiological, cognitive and behavioral characteristics of ant workers and also on the energetic investment in specialized brain compartments that underlie behavior. We combine techniques applied to the study of collective animal behavior (natural history, ethology, individual tracking and learning experiments) with neurobiology methodologies (immunohistochemical imaging and high performance liquid chromatography) in ant species varying in social complexity. This novel and integrated approach will allow us to analyze the evolutionary relationship between social complexity and brain evolution.