The study of high temperature extreme environments challenges our understanding of the upper tolerances of microbial life and may provide a window to understanding how life originated on earth. The Tramway Ridge geothermal site on Mt. Erebus, an active volcano in Antarctica, is the most geographically isolated geothermal site on earth. The extreme isolation of Erebus makes it an excellent system for studies of microbial speciation, biogeography, and evolution of thermal adaptation. An earlier genetic survey of the Tramway Ridge subsurface microbial community conducted by our group revealed an unprecedented diversity of extremely novel microbes distantly related to known bacteria and provided the impetus for this current Marsden funded research effort.