Sociobiology theory proposes that similarities between human and nonhuman social structures reflect common evolutionary origins, but this hypothesis remains unproven. To test the hypothesis, researchers compared behavior-associated brain gene expression between humans and honeybees.
The authors exposed groups of honeybee nestmates to two different social stimuli: an unrelated bee, which elicits aggression, and a queen larva, which elicits caring behavior. The authors observed wide variation in individual bees’ responsiveness to these stimuli, including a subset of bees that consistently failed to respond to either stimulus.
Next, the authors generated gene expression profiles for a high-level sensory integration center in the bees’ brains and identified genes whose expression differed significantly between unresponsive bees and other bees.
Comparison of differentially expressed genes with human gene sets associated with autism spectrum disorder (ASD) revealed significant overlap. This overlap between human ASD-associated genes and genes associated with social responsiveness in honeybees suggests that genes responsible for social behavior are highly conserved across the animal kingdom.
The results also illustrate how comparative genomics can be used to test the predictions of sociobiology theory, according to the authors.