For years, biologists have pigeonholed archaea as extremophiles-creatures that live in extreme conditions. Indeed, many species of archaea thrive in environments that would kill other organisms, from Yellowstone hot springs to the hyper-salty Dead Sea to streams polluted by mining waste where the pH level is equivalent to battery acid. Archaea even inhabit the warm, dark environs of our intestines and mouth.
While extremophiles have been the subject of intense research, scientists are just now beginning to focus on the large number of archaeal species that inhabit more mundane environments, including soils and seawater.
At 1:30 p.m. PT Monday, Dec. 11, an international panel of researchers will present new findings about the extreme and not-so-extreme world of archaea during the annual meeting of the American Geophysical Union (AGU) in San Francisco's Moscone Center South, Room 256. The session will be moderated by Chris Francis, assistant professor of geological and environmental sciences at Stanford University, and David Valentine, associate professor of Earth science at the University of California-Santa Barbara.
''Archaea have been a pretty hot topic for a number of years in the microbial ecology and physiology realm,'' Francis said, noting that most biology textbooks now divide life into three domains-Archaea, Bacteria and Eukarya, a category that includes plants, animals, fungi, algae and protozoa.
Scientists believe that the most recent common ancestor of all three domains was a single-cell organism that lived in extreme conditions when the Earth was very young and very hot, and the atmosphere contained large amounts of methane instead of oxygen