Scientists Discover Life as We Don't Know It
A research team funded by NASA has made a momentous discovery: arsenic-based life. Kind of.
According to this NASA news feature, common Gammaproteobacteria from California's Mono Lake (a body of water known for its alkalinity and hypersalinity) were grown in a laboratory "on a diet that was very lean on phosphorus, but included generous helpings of arsenic." Researchers eventually removed the phosphorus altogether, substituting it with arsenic. This resulted in the bacteria continuing to grow, having incorporated that arsenic into its DNA.
What makes this truly astounding is that up until today's announcement, life with a chemical composition outside the confines of the phosphorus/carbon/nitrogen/oxygen/hydrogen/sulfur ensemble existed only in the realm of science fiction. However, as is the case with many things these days, science fiction is fast becoming science fact.
Related Links:
http://astrobiology.nasa.gov/articles/thriving-on-arsenic/