Organisms can alter their physical form by varying the genes that they activate. However, the evolutionary forces that shape genes activated in different forms remain unclear. The objective of this research program is to gain a greater understanding of how natural selection affects genes that are differentially activated between forms. Goodisman and Yi will use social insects as models for investigating this question. They will use molecular genetic techniques to detect genes differentially activated between different social insect castes and sexes. They will then use evolutionary analyses to (1) test the effect of caste-specific gene activation on molecular evolution and (2) test the effect of differing mating system on the evolution of sex-specific genes.
This research is of broad scientific importance because it advances our understanding of the evolution of genes that lead to the development of different organismal forms. Goodisman and Yi will uncover how genes that are expressed under distinct environmental conditions evolve. Their studies will also add to our knowledge of the evolution of sex differences. Finally, this research increases our understanding of the molecular basis underlying the success of social insects, which are among the most ecologically successful and economically important of animal species.
The development of sociality represented an extremely important innovation in biological history. Social animals enjoy great ecological success because they effectively work together to complete complex tasks. However, the ecological pressures and molecular foundations leading to the development of social actions remain poorly understood. Therefore, investigation of the elaboration and molecular basis of societies remains an important area of scientific investigation. This research focused on understanding the genetic basis of sociality in social insects. Social insects, which include ants, termites, some bees, and some wasps, represent critical models for understanding social behavior, because they show the most advanced societies of any animals. In addition, social insects, such as bees, are key pollinators of crops. Other social insects, such as some termites, ants, and wasps, are serious pests. Thus understanding social interactions in insects can help us understand sociality in other species and can have important economic implications. This research program used diverse methods to study sociality. Genetic methods were used to investigate the genes involved in social differences. Computational and comparative studies in honeybees and fire ants revealed that genes involved in social differences change rapidly over time. In addition, rapidly changing genes were likely to be involved into social behaviors. Thus these results provided information on the characteristics of genes involved in social differences. This research also investigated the molecular basis of social variation. Investigations across diverse insects, including ants, bees, and termites, revealed that inherited molecular information affects the function of genes involved in development. This transmissible epigenetic information was strongly conserved across different species and therefore was fundamentally important to insect development. Theoretical techniques were used to study how different types of environmental pressures affect changes in social insect populations. Results revealed that genetic changes affecting reproductive queens within societies were more likely to have effects than those affecting sterile workers. In addition, the relationships among individuals within colonies was found to have important consequences for the development of social behavior. Genetic methods were used to study the breeding biology and movement of invasive social insects. Genetic studies of invasive ants and wasps revealed how mating behavior affected colony success. In addition, important information regarding the patterns of invasion of social insects provided insight into how invasive species move into new habitats. Finally, this research used behavioral methods to study how pest social insects reproduce and survive. Behavioral studies uncovered how pest wasps successfully find mates and survive winter conditions. Thus these results revealed important characteristics that help pest insects survive harsh conditions. In addition to completing several research objectives associated with understanding sociality, this program also led to the training of several scientists. Students of differing levels and backgrounds worked together to complete research projects and learn about scientific discovery. This program also brought together scientists from different academic institutions to help promote diversity within the field of biology. The results of this research program were published in peer-reviewed journals. In addition, a series of scientific talks on social behavior were given to both professional and lay audiences in order to help educate the community on the importance of insects and social behavior. In conclusion, this research focused on understanding the molecular and genetic underpinnings of social behavior in important insect species. The research ultimately led to considerable new insights into the development and molecular basis of sociality. Finally, this program helped train a generation of new scientists and inform the public on the significance of social behavior.
