New Life Found Right Here on Earth

Found: something that can absorb arsenic and survive. Where found: here on Earth.

NASA has announced the discovery of strange life right here on the homeward, in the form of a bacterium that can not only swallow one of the world's most deadly poisons — arsenic — but thrive on it to the extent that it absorbs the deadly liquid into its DNA.

The bacterium in question has been termed GFAJ-1, and it was found thriving quite well, thank you very much, in Mono Lake, in California.

Here's the significance: This bacterium has been able to substitute arsenic for phosphorus in its building blocks. Remember that phosphorus is one of the six major elements that scientists consider essential for life — the others being carbon, hydrogen, nitrogen, oxygen, and sulfur. But GFAJ-1 has proven the ability to jettison phosphorus for the quite-similar-in-structure arsenic and run with arsenic instead.

Not coincidentally, Mono Lake has high levels of arsenic. Scientists probably knew what they were looking for, but they still seemed surprised when they found it.

So what does all this mean? Is E.T. made of arsenic? Possibly. But that's probably not the correct question to ask.

The better question would be this one: How do we need to change the way we are looking for extraterrestrial life? Efforts in this area have long been preoccupied in finding life that closely resembles the familiar — humans or animals or microbes that we can readily identify and understand. But the more exotic lifeforms like GFAJ-1 we find, the more we will be forced to re-examine our prejudices and assumptions in determining the parameters of the search.

Will we recognize life when we bump up against it? Will it recognize us? We should be prepared for outlandish answers to these questions.