Hopane, a component of oil, is a large, complex compound with many branches and rings. Microbes typically leave behind larger, more complex compounds that require more effort to break down. In a new study, scientists were surprised to find that in the frigid abyss on the seafloor of the Gulf of Mexico, microbes did decompose hopane. Hopane is generally so resistant to degradation that oil-spill scientists have come to rely on it as a reference against which to measure the relative degradation of