Steven Benner, a distinguished fellow at the Foundation for Applied Molecular Evolution, right, speaks during a press conference as Mary Voytek, director of the Astrobiology Program at NASA looks on, Thursday, Dec. 2, 2010, at NASA Headquarters in Washington. NASA-funded astrobiology research has changed the fundamental knowledge about what comprises all known life on Earth. Researchers conducting tests in the harsh environment of Mono Lake in California have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. Photo Credit: (NASA/Paul E. Alers)