GFAJ-1: Earth’s First Confirmed Arsenic-Based Life Form

In a big news conference today, NASA announced that researchers had “taught” bacteria to survive on arsenic instead of the phosphate it usually eats.  Researchers had long theorized that there could be bacteria which use arsenic instead of phosphorus.   Dr. Felisa Wolfe-Simon presented a paper with her prediction in 2006.
She decided to start looking for them in an arsenic-rich environment, which is how the floor of California’s Mono Lake came to be dredged for samples.  She then gradually removed phosphorus from their little tanks and added more arsenic, and eventually GFAJ-1 was living solely on arsenic.Aside from being an interesting party trick, NASA wants you to know that your carbon-centrism simply will not stand in the progressive future where the Horta is a valid life form.  We have long taken it as a truism that life requires certain parameters in order to evolve.  Among other things, the “big six” elements: carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus.  But it turns out that most of these parameters are wrong, or at least outdated.  If life can survive and even thrive in the ecosystem surrounding an oceanic volcanic vent, then how can we possibly rule out the potential for life on other planets?The fact that this bacteria can eat arsenic also invalidates a lot of the tests we use to detect life, and hospitable climates.  We haven’t historically gone looking for arsenic as a precursor to life, but clearly now we ought to.  And a lot of other elements, beside.  Which elements should we be hunting for, exactly?  Well, that is the question.  We used to hunt for the Big Six, but now it looks like there’s a Big Seventh.  Is there a Big Eighth, or a Big Ninth?  At this point, that seems very probable.Phosphorus is what our cells use to make DNA.  But the bacteria GFAJ-1 uses arsenic instead.  If something so weird can be living right here under our noses on Earth, then who’s to say what’s living on Mars?  Or more likely on Europa?Although the big story on GFAJ-1 today is all about the hunt for extraterrestrial life, surely some of the long-term discussion will be about pollution control.  If you can grow a bacteria that eats arsenic, they would certainly be handy in some of our planet’s arsenic contamination sites.  Arsenic pollution is a huge problem in groundwater across the world.  If GFAJ-1 can help out, then it will truly become our alien savior!
Photo credit: Wikimedia Commons/NASA