This research project will investigate a new hypothesis about how viruses may control the structure and function of microbial communities. The traditional view of viruses is that they negatively impact the fitness of infected hosts. In other words, they are viewed strictly as pathogens, in which the host tries to eliminate the virus. This project will explore an alternative hypothesis: that chronic viral infections contribute positively to host fitness, increasing the success of the virus-host pair by protecting their hosts from infection by even more pathogenic viruses. Under this model, the competitive advantage provided by many viruses plays a direct role in maintaining microbial biodiversity. Microbial communities in hot springs in Yellowstone National Park will be used to test this hypothesis by: i) linking temporal changes in virus abundance and diversity to host genetic and taxonomic diversity, ii) identifying chronic viruses, and quantifying the fitness consequences of chronic viral infections in the laboratory, iii) assessing the effects of removing viruses in laboratory and field experiments, and iv) developing a theoretical and computational model of host-viral interactions that includes the costs and benefits of chronic infections. It is anticipated that this research will provide new insights into how viruses influence not only microbial biodiversity, but also the biodiversity of plants and animals.
This research will be of broad scientific importance. It is known that microbes play a significant role in life on earth, including as the foundation for earth's food webs, influencing carbon and nitrogen cycles, and in human health. Viruses infect all forms of life, including microbes. This study will reveal more about how viruses impact the composition and function of ecosystems. The research project also will engage K-12 teachers, students, and the public on the science of biodiversity using Yellowstone National Park as a highly attractive and visible venue for public interest in science. The investigators will create field courses for K-12 science teachers, virtual classrooms from Yellowstone to K-12 schools, online courses and workshops, and nationally aired films focused on microbial research in Yellowstone. Results from this project are expected to reveal fundamental new knowledge about the biodiversity of life on earth.
