From the advent of antibiotic resistant bacteria to host switching in viral pathogens, many of the problems we face with infectious disease are evolutionary in nature. Theoretical work suggests that pathogen infectivity and virulence evolve in response to the manner in which hosts move and contact one another (the ?social contact network?). However, there has been relatively little experimental work to test these predictions. This project combines mathematical and computational approaches with real-time microbial evolution to explore how network structure influences host-pathogen evolution. The experimental approach involves a model community comprised of bacteria (hosts) and their viruses (pathogens). The microbes are embedded in subpopulation arrays and a high-throughput robot is used to control movement between subpopulations. As the subpopulation network structure is varied, the changes in both the pathogen and its host are tracked in real time at genetic and physiological levels. The primary investigator will focus on how the structure of the social network influences the evolution of different components of the life cycle of the pathogen (e.g., host entry and exit), the ?evolvability? of the pathogen (i.e., its proclivity for rapid trait change), and the evolution of the host in response to the pathogen and vice versa.
The focus of this project is evolution. More generally, the subject of evolution occupies a central pillar of modern biology. Nonetheless, there is widespread public skepticism about evolution in the United States. This doubt is fueled, in part, by basic misunderstanding of evolutionary principles. In the classroom, this situation reflects a failure to communicate central aspects of evolutionary theory, its scientific foundation, and its relevance for the public good. The primary investigator will design and publicly disseminate a set of new real-time evolution modules for use in undergraduate laboratory courses. The focus will be disease evolution, using the innocuous microbial host-pathogen systems described above. These modules will illustrate evolutionary processes through hands-on and inquiry-based experiments. Additionally, the primary investigator will design a year-long sequence in experimental evolution in collaboration with researchers from other disciplines (including bioengineering, cancer research, genome sciences, fisheries, and electrical engineering). In this sequence, students will pose and test their own evolutionary hypotheses. In the process, students will learn about the nature of scientific research and effective experimental methodology. Both educational and research aims of this project will directly involve graduate and undergraduate students and special efforts will be taken to involve underrepresented groups.
