"They also harbor many unusual organisms and unique metabolic strategies. Some of the organisms found living at the highest temperatures appear to be very primitive forms, close to a last common ancestor of life. These forms are able to exist on inorganic by-products derived from the aqueous weathering of rocks." Not requiring sunlight for their metabolism, nor organic inputs from other organisms, these "chemoautotrophic" (chemically-based) forms provide models for the kinds of organisms that could exist in subsurface environments of Mars, Europa, and other planets.
Hydrothermal systems are also very interesting places to explore for novel organisms and their metabolic processes of interest to biotechnology. "The famous example of PCR (polymerase chain reaction), a genetic process whereby even tiny sequences of a genome can be cloned and amplified, was discovered in a Yellowstone hot spring," Farmer explained. "This discovery revolutionized molecular biology and spawned a multi-billion dollar industry."
Franco Piranjo (Geological Survey of Western Australia) will present an overview on the nature of hydrothermal environments and Anna Louise Reysenbach (Portland State University) will provide an overview of their microbiology.
Mike Russell, from the Isotope Geoscience Unit at the Scottish Universities Environmental Research Centre, also co-chairs the session and will present a talk on hydrothermal systems as a potential cradle for early prebiotic chemistry and life.
Sherry Cady, Geology Department at Portland State University, will review what we have learned about life near its upper temperature limit. Tullis Onstott, from the Department of Geosciences at Princeton, will discuss the exploration for a deep, hot microbial biosphere in deep gold mines in South Africa.
Malcolm Walte
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Contact: Ann Cairns
acairns@geosociety.org
303-447-2020 ext1156
Geological Society of America
13-Jun-2001