Navin Elango, Brendan Hunt, Michael Goodisman, and Soojin Yi of the School of Biology have made progress into understanding the genetic basis of the caste system in the social honeybee Apis mellifera. In work published in the July 7th issue of the Proceedings of the National Academy of Sciences, Elango et al. discovered that honeybee genes affecting caste development show specific modifications, called 'DNA methylation'. This indicates that caste formation may be controlled by simple molecular mechanisms. This research provides insights into the molecular basis underlying social behavior and helps explain how genomes evolve.