The following is from NASA's website @ http://www.nasa.gov/topics/universe/features/astrobiology_toxic_chemical.html where you can read this epic and awesome article...Thank you for this NASA, keep it up.
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. The microorganism substitutes arsenic for phosphorus in its cell components.
Ed Weiler said:
The definition of life has just expanded, As we pursue our efforts to seek signs of life in the solar system, we have to think more broadly, more diversely and consider life as we do not know it.
I have my own theories on the origin of and now pronounced new life but I'm most interested to hear in what anyone else can gather from the facts that are out there at this point. I believe the full study will be published soon but in the mean time some informal guesses at what could be the cause or effects of this could be quite entertaining.