Microbes are invisible to the naked eye, but play key roles in maintaining the planet’s biogeochemical cycles. In the Earth’s subsurface, microbes have adapted to thrive in the relatively stable extreme conditions. To learn more about how some of these populations respond to disruptions in their environment, researchers in the petroleum industry conducted a comparative genetic analysis of the microbial communities in multiple oil wells within an offshore oil field. The analysis utilized tools developed at the U.S. Department of Energy Joint Genome Institute (DOE JGI), a DOE Office of Science User Facility.