All organisms interact with members of their own species, and such interactions can directly and indirectly influence genetics, behavior and evolution. Biologists have only recently begun to consider how social partners change the rules of evolution and alter the way that selection shapes biodiversity. This project will follow an insect model system in the wild, to examine how differences in social contexts translate into differences in classically understood selection. The work includes direct behavioral observation, as well as the development of infrared video monitoring systems to record data remotely. Fieldwork will be conducted at the Mountain Lake Biological Station so the project interfaces with the highly successful MLBS-Research Experience for Undergraduate program to provide training opportunities for new scientists, as well as developing mentoring skills for graduate students and postdoctoral fellows. The results of this work will determine how import social context and social networks are to the process of behavioral evolution.
This project examined the importance of social neighbors in determining the form and direction of natural selection. If the identity, or more importantly the characteristics, of social partners alters the form of selection, then any individual might alter its fitness by associating with different individuals. At the level of the population, individuals could even reverse the direction of selection simply by sorting into groups of different types. Forked fungus beetles live, mate and reproduce on shelf fungus on logs in the forest. The results of this work show that, somewhat unsurprisingly, male beetles with larger horns and body size gain more matings and have higher reproductive success, generating positive selection for larger size. Beetles with larger neighbors also have lower mating success. However, males assort so that large and small beetles are most often found together, reversing the selection consequences of neighbor size. Behavioral experiments suggest that this opposite size assortment does not result from simple choice (small beetles choosing to be near large beetles or vice versa), but from some more complicated behavioral dynamic. Because selection, and thereby evolutionary process, can vary dramatically on the scale of small social groups, the population level analyses typically conducted on natural populations may underestimate variation in selection. This may ultimately lead to more variation being maintained in populations than theory predicts. Statistical approaches presented in the these publication have led to increased awareness and application of multilevel selection analysis.? Novel approaches to social network characterization in wild animal populations have also been presented and provide a new approach to characterizing conspecific interactions in the wild. The work under this project was conducted at Mountain Lake Biological Station, where it has been a core component of the MLBS REU Program. Over the last five summers, the project has provided research opportunities to 2-3 REU students each year, many of whom have gone onto PhD programs in evolutionary biology and behavior. The experience of mentoring these REU students has been instrumental in developing the career of the graduate assistants and the postdoc supported on the project, who cite the mentoring experiences among the most important professional preparations they have received. An additional 5 independent study projects were conducted by non-REU undergraduates. Three PhD students have received training in molecular techniques and field methods as part of this work. Close interactions with ArtLab participants during the annual artist residency program at MLBS explored the connections between art and science. The outcome of such interactions are exemplified through the work of Ana Golici, the 2013 ArtLab Artist-in-Residence, who examined the bio-origami of beetle wings after conversations and visits to the beetle lab.
