@iamthemob how much would it alter the perception if it preferred phosphorus but developed, out of necessity, the ability to utilize arsenic?
According to the news article: In the laboratory, the researchers successfully grew microbes from the lake on a diet that was very lean on phosphorus, but included generous helpings of arsenic. When researchers removed the phosphorus and replaced it with arsenic the microbes continued to grow.
That rather sounds like they are at least adapted to arsenic. Note that P and As are in the same group (column) of the periodic table. That’s likely why arsenic is poisonous to most life.
There’s a nice write-up of the finding at Pharyngula. Here’s PZ Myers’ take on the news:
So what does it all mean? It means that researchers have found that some earthly bacteria that live in literally poisonous environments are adapted to find the presence of arsenic dramatically less lethal, and that they can even incorporate arsenic into their routine, familiar chemistry.
It doesn’t say a lot about evolutionary history, I’m afraid. These are derived forms of bacteria that are adapting to artificially stringent environmental conditions, and they were found in a geologically young lake — so no, this is not the bacterium primeval. This lake also happens to be on Earth, not Saturn, although maybe being in California gives them extra weirdness points, so I don’t know that it can even say much about extraterrestrial life. It does say that life can survive in a surprisingly broad range of conditions, but we already knew that.
So it’s nice work, a small piece of the story of life, but not quite the earthshaking news the bookmakers were predicting.