In the social insects the evolution of an ‘altruistic’ sterile worker caste remains a fundamental question for evolutionary biology, as it requires the existence of genes that reduce personal reproduction. The first step to solving the mystery is to identify the genes that regulate worker fertility. Understanding the molecular mechanisms that underlie this altruistic trait is important as it will provide insight into the evolution of eusociality. My Ph.D. research project helped uncover the molecular mechanisms that underlie worker sterility using the honey bee. My interdisciplinary thesis also reflected upon my empirical research by investigating how key molecular biology techniques have been developed from natural systems.