Posted: Fri, Dec 3, 2010, 7:10 AM ET (1210 GMT)
NASA-supported researchers announced Thursday the discovery of a terrestrial microbe that make use of the element arsenic, a discovery that could have implications for the search for life beyond Earth. Scientists discovered the microbe, GFAJ-1, in Mono Lake in California. In lab tests where the microbe was exposed to arsenic, it incorporated the element into structure, including its DNA, replacing phosphorous. While the discovery involved a terrestrial life form, scientists said that the discovery could inform searches for life beyond Earth because it demonstrates that alternative biochemistries are possible. The announcement attracted significant attention because of rumors, based on a NASA announcement of a press conference about the discovery, that NASA would instead announce a discovery more directly associated with extraterrestrial life.
