The behavior performed by an individual may result not only from its own genes and the environment in which it resides, but may also reflect genes (and the behaviors these genes underlie) carried in the individual's social partners. The effects of genes carried in a social partner on the behavior of another individual are termed "indirect genetic effects." Indirect genetic effects are predicted to be particularly important in the evolution of social behavior, because they may alter the way natural selection operates on individuals. However, indirect genetic effects are difficult to isolate and measure because the genetic component of the social environment, specifically the genes in social partners with which individuals interact, must be held constant. Guppies, Poecilia reticulata, provide a unique set of tools for exploring the impacts of indirect genetic effects on the expression and evolution of social behavior: inbred lines that allow for the control of the genetic component of the social environment and wild populations that are known to vary in social behavior in response to different levels of predation. This project will provide the first test of indirect genetic effects in a behavioral system. It will then explore variation between families in responsiveness to social environment, indicating that responsiveness to social groups may evolve. Finally, the project will investigate variation across populations in responsiveness to social environment, correlated with predation regime, which may provide evidence for the evolution of indirect genetic effects.
Broader Impacts Four undergraduate students, including one NSF-REU student from summer 2004 have participated in this project, one of which presented her study on differences in male and female inspection behavior at both an REU symposium and a national meeting. PIs in this research program have mentored a total of eight undergraduates at Indiana University, one through the Women in Science Program and four through the NSF-REU behavior program. More than half have been women and/or minorities. All but one of the students have or will complete a research project with this funding, from start to finish, including experimental design and data collection, analysis and presentation. Two students have gone on to present their results at national meetings such as Sigma Xi. All but one of the eight are in or are applying for graduate school or veterinary school. This project has also been used to introduce the topics of animal behavior and behavioral evolution to several undergraduate courses, at both Indiana University and Marion College.
