Abstract Soils are a great source ofbiodiversity on earth due to its heterogeneous chemical and physical properties. In this study, the first comprehensive examination of prokaryotes and their viruses, will be perfomed in an extreme thermal soil (temperature range 60-85C) located in Yellowstone National Park. Prokaryotes and their viruses are inextricably tied and understanding their relationships in this environment promises a new view ofthermophily and evolution. Molecular techniques will examine phylogenetic relationships of thermal soil prokaryotes and their viruses, and extreme thermophiles and viruses will be isolated using traditional culturing methods and novel methods that take advantage of the flow-through properties of a bio~lm reactor and a soil chemostat. Information derived from this study will expand our understanding of the distribution of thermophily in the microbial world and will be of fundamental importance to science. The knowledge and resources gained from this study are predicted to be of significant value to the biotechnology industry.
