Mendel discovered the genetic basis of simple traits of peas, such as flower color and seed shape, more than 150 years ago, but researchers still have much to learn about how genes control complex traits such as social behavior or mating strategy. These complex traits include multiple components, so they are unlikely to be shaped by a single gene. Recent evidence from insects, birds, plants, and fungi suggests that many different complex traits may be controlled by common genetic structures called supergenes, which lock together two or more genes with coordinated actions so that beneficial combinations are transmitted together to offspring. In this study, the researchers will investigate characteristics of a supergene that controls social organization in a group of ants. The project will specifically ask about how an ancient supergene changes in form and function in a group of related species. In addition to expanding the current knowledge of how complex traits emerge and persist, this study will also provide new insights into the causes and consequences of alternative social strategies in ants. Students will participate in every aspect of this study, and the research team will participate in outreach events to raise community awareness about entomology. Undergraduate students will gain hands-on experience in contemporary genomics techniques, both in the classroom and as research assistants. Graduate students will compile existing knowledge about the causes and consequences of alternative social strategies across all social organisms, which will broaden the scope of the discoveries from this project.
Social organization involving cooperation among non-relatives has originated repeatedly in social insects, yet the proximate and ultimate drivers of this transition remain enigmatic. The proposed research will build upon the recent discovery of an ancestral supergene composed of about 500 linked genes that underlies social structure in multiple socially polymorphic Formica ant species. Emerging evidence suggests that supergenes commonly control complex traits, from mimetic coloration in butterflies to mating strategies in birds, but scientists are only beginning to understand the characteristics and dynamics of these genomic structures. This project will address in parallel two major questions: how do autosomal supergenes evolve and persist, and how and why do societies composed of non-relatives repeatedly evolve. Aim 1 will investigate whether alternative supergene variants undergo changes in gene content, gene order, and protein coding sequence as they persist in speciating lineages. Undergraduate researchers will be trained in genomics and bioinformatics techniques and will lead intraspecific analyses of their own Formica species. In complement, aim 2 will examine how supergene genotype influences individual- and colony-level traits. Students in introductory biology classes will participate in data collection for this aim. Finally, aim 3 will determine whether the distribution of social organization and genetic control varies along biogeographic axes. A graduate student seminar will broaden discoveries from this aim by conducting a meta-analysis of ecological drivers of social polymorphism across social insects. This project will provide excellent learning opportunities for students at all levels and is poised to expand the understanding of social evolution and the genetics of complex traits.
This work is being funded jointly by the Behavioral Systems Cluster in the Division of Integrative Organismal Systems and the Evolutionary Processes Cluster in the Division of Environmental Biology.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
