How do females pick a mate? Do social interactions modify innate preferences? Understanding how genes and social environment interact to produce mating patterns is important for understanding how the spectacular diversity in animal morphology evolves and is maintained. This proposed work aims to determine whether social interactions and visual and olfactory communication are associated with the maintenance of animal morphological diversity by determining whether mate preferences for physical appearances can be learned and mediated by the presence of olfactory signals in one of the most diverse groups of animals: butterflies. Having determined that females can learn to like specific male physical appearances, the chemical signals of male butterflies will be modified to 1) determine whether female innate preferences for male odors facilitate female learning preferences for physical appearance, and 2) determine whether females can learn preferences for specific male odors. Male-male interactions during female mate choice trials will also be observed to determine how male-male competition mediates female preference. This will be the first study examining 1) the role of pre-mating female experience on the relative importance of male appearance and odor in any animal; and 2) the combinatorial role of male activity and male appearance in non-vertebrates, illuminating how social interactions and multiple signals influence mating patterns and drive the evolution of diverse animal forms. This research will train an undergraduate researcher, and will be used to engage non-science majors in scientific thought processes during mentoring sessions and social interactions via the graduate affiliate program at an undergraduate dorm. Findings from this project will be displayed on a public website on the biology of Bicyclus anynana, in the form of reader-friendly multi-media web-pages accessible to high-school students, the public at large and the scientific community.
Data suggest that childhood social experience influences adult social behavior in humans. However, determining the components of childhood social experiences that are important for shaping different aspects of adult behavior is difficult, due to the complexity of the social and physical environment experienced during childhood. One way to circumvent this problem of complexity is to use a different animal as a model for studying specific aspects of behavioral development in highly controlled environments. Here, we used a species of butterfly (Bicyclus anynana) to examine differences in male and female social learning of what is physically attractive in the opposite sex. In addition, we examine whether non-visual signals, such as odor, influence this learning process in females. Butterflies are good models for studying social learning of physical attraction because, like humans, they often interact with other individuals prior to selecting a mate, and they pay close attention to physical appearance (which for butterflies means wing pattern) during the mate selection process. However, unlike humans, they have short life spans and can be reared in highly controlled laboratory conditions. We found that both male and female young butterflies change what they find physically attractive after interacting with an older butterfly of the opposite sex. However, males and females do not change what they find attractive in the opposite sex in the same way. Males and females learn preferences for different body parts, and exhibit different biases in what characteristics are easy to learn. Females learn preferences for forewing patterns, while males learn preferences for hindwing patterns; and females are biased towards learning preferences for male patterns with enhanced ornamentation, while males are biased towards learning preferences for female patterns with reduced ornamentation. In addition, we found that the odor influences this learning process in females- if a young female interacts with an older male that smells good, she will learn a preference for males with his forewing pattern; but if a young female interacts with an older male that smells bad, she will learn to avoid males with his forewing pattern. Our finding that young male and female B. anynana butterflies exposed to the same wing pattern will learn preferences for different parts of that pattern (hindwing versus forewing), coupled with our finding that males and females exhibit learning biases in different directions (reduced versus enhanced ornamentation), suggests that, at least in butterflies, gender may influence perception of visual social signals. Future work in this, and other systems, will allow us to explore these differences in perception, and to determine whether this difference in visual perception is pervasive amongst animals as well as why these sex-specific differences in response to visual social signals exist. Our finding that odor influences whether females learn to prefer or avoid specific male wing patterns demonstrates, for the first time, that signals in other sensory modalities (such as odor) influence the learning of visual mate preferences. This finding gives us new insights in to how visual preferences for physical traits may be learned. In addition to enhancing our understanding of how visual social learning works by producing the first evidence of learning biases in visual preference learning, the first evidence of differences between male and female learning biases in visual preference learning, and the first evidence that odor influences whether females learn to prefer or avoid male visual characteristics, this grant assisted in funding both the training of undergraduate women and minorities in the sciences, and outreach activities to engage the public in the sciences. Two undergraduate students, who were either female or ethnic minorities, were trained in scientific methodology, data collection, and data analysis during this study. We also developed butterfly themed activities to engage elementary school aged children in science at museum and national society sponsored public science fairs, participated in middle school science fairs to engage middle school aged youths in scientific exploration, and built a science trips program for primarily non-science majors at our university, in an effort to engage college age students with otherwise limited exposure to science.
