Contents

10 May 2002
Vol 296, Issue 5570

About The Cover

Cover image expansion

COVER Bubbles from the acidic thermal mudpot "the Gumper," Yellowstone National Park, USA. Studies of microbes from hydrothermal systems such as this one and many other environments, not all extreme, are providing information on how microbes are distributed, evolve, and thrive, as well as their role in the evolution of Earth's atmosphere and oceans, as highlighted in a special section on environmental microbiology. 1055 [Photo: A.-L. Reysenbach]