The work "confirms that there are subsurface environments that can support life without using oxygen," said Martin Fisk, a biogeochemist at Oregon State University who also studies oceanic crust microbiology at the Juan de Fuca plate, but was not involved in the new research.īiogeochemist Everett Shock of Arizona State University, also not involved in the research, isn't yet ready to rule out multicellular life. That web is relatively simple compared to sunlight-based ecosystems, said Teske, and it's unlikely that multicellular life will be found there, as it's too hot and energy-poor compared to the places where higher life is found. That matter, along with metabolic byproducts like methane, would support other organisms, ultimately creating a web of life. The researchers put their rocks in a laboratory apparatus designed to simulate that environment, then spent the next seven years observing what happened. Teske and Lever's team collected samples of crust from the Juan de Fuca Plate, about 120 miles off the coast of Washington, drilling from boreholes made by other researchers some 1.5 miles below the ocean's surface and beneath another 1,000 feet of sediment.Īt that depth, there exists rock and water and carbon dioxide, and few if any traces of organic matter produced from sunlight in the illuminated surface world.
The question is, how far does it extend?" "We now have the best available evidence that there is in fact microbial life in the cracks and fissures of deep ocean basalt. It was time to put it all together," said microbial ecologist Andreas Teske of the University of North Carolina, a co-author of the new study. "All these pieces of evidence have been coming together for over 15 years. Other researchers found DNA traces of microbes in the oceanic crusts, further making the case for life, but just what the microbes were doing remained uncertain.
At the edges, where rocks arrive millions of years later, the chemicals are gone. At the centers, near where they form, rocks are suffused with energy-rich compounds that support microbes.
In coming years, researchers noted that oceanic crusts, which form when rock heated by Earth's core pours slowly through mid-ocean cracks between continental plates, differed greatly between the centers and edges.
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