Arsenic-based life form discovered on Earth

by Washington Post Staff | The Washington Post | December 2, 2010

NASA held a press conference Thursday afternoon in which they revealed the discovery of arsenic-based life forms on Earth. As Marc Kaufman explained:
All life on Earth from microbes to elephants and us is based on a single genetic model that requires the element phosphorus as one of its six essential components.

But now researchers have uncovered a bacterium that has five of those essential elements but has, in effect, replaced phosphorus with its look-alike but toxic cousin arsenic.

News of the discovery caused a scientific commotion, including calls to NASA from the White House and Congress asking whether a second line of earthly life has been found.
While speculation had been building of the possible discovery of extraterrestrial life, Melissa Bell brings us back to Earth:
Before you get disappointed, realize that while not as sexy as a little green man, it is a big deal. No other life form exists off arsenic. It had long been the assumption that without six certain essential elements carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur life could not exist. This discovery shows "life-as-we-know-it could be much more flexible than we generally assume or can imagine," Felisa Wolfe-Simon a NASA biochemist told the Post's Marc Kaufman.
The Post's satire columnist Alexandra Petri had this to say about the new discovery:
I picture this bacteria as sort of a hipster. "Oh, you're still using phosphorus?" it asks. "Yeah, I liked phosphorus during its blue period, but I've moved on to arsenic." "Isn't that lethal?" a regular earth bacteria asks, nervously. "It's an acquired taste," the arsenic bacteria responds. Apparently, the place to find this sort of bacteria is Mono Lake, California. Admittedly, the announcement that someone has found a totally alien life-form in California is not exactly breaking news. Usually the California response to finding completely alien life is to give it a reality TV show.
Still, this is big news.