On the Origins of Diversity in Social Behavior

Abstract

Here we discuss the origins of diversity in social behavior by highlighting research using the socially monogamous prairie vole. Prairie voles display a rich social behavioral repertoire involving pair bonding and consoling behavior that are not observed in typical laboratory species. Oxytocin and vasopressin play critical roles in regulating pair bonding and consoling behavior. Oxytocin and vasopressin receptors show remarkable diversity in expression patterns both between and within species. Receptor expression patterns are associated with species differences in social behaviors. Variations in receptor genes have been linked to individual variation in expression patterns. We propose that "evolvability" in the oxytocin and vasopressin receptor genes allows for the repurposing of ancient maternal and territorial circuits to give rise to novel social behaviors such as pair bonding, consoling and selective aggression. We further propose that the evolvability of these receptor genes is due to their transcriptional sensitivity to genomic variation. This model provides a foundation for investigating the molecular mechanisms giving rise to the remarkable diversity in social behaviors found in vertebrates.