Research could redefine 'Life as we know it"

January 3, 2011 11:08:43 AM PST
For as long as scientists have studied life, one combination of elements has remained potently consistent.

They call it 'CHNOPS' -- an acronym for Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous and Sulphur. They are the six building blocks of life. We find those elements in every person, bug, tree, and microbe. Today, a a local scientist proposed that we add a seventh element, arsenic, to the mix.

Dr. Felisa Wolfe-Simon, a NASA research fellow at the United States Geological Survey in Menlo Park, made science history, today, by announcing her discovery of a microbe that breaks the rules of CHNOPS. Her research claims that a strain of the Halomonadacea family of Gammaprotobacteria has substituted arsenic for phosphorous in some of its molecules.

Wolfe-Simon hinted about her studies in interviews with ABC7, last fall, and then requested an embargo until after the full details of today's announcement. "The scientific implications suggest there are alternatives to the unity of biochemistry, " Wolfe-Simon said at the time.

Those implications could be profound. They redefine the traditional understanding of life as we know it, and expand the possibilities of life as we might find it on other worlds. "It would strongly suggest that there are probably other options in the universe."

Wolfe-Simon found the unusual microbe in the muck of California's Mono Lake. "If you want to look for something interesting on Earth, then Mono Lake is the place to do it," she said last September.

Mono Lake is about one million years old, and never drains. Its arsenic has accumulated to three times the normal levels. In an earlier study, Wolfe-Simon identified and isolated an organism that uses arsenic for food. She took that bacteria to her Menlo Park laboratory and systematically increased its arsenic levels, only to watch the organism thrive. "That much arsenic would be extremely poisonous to us," Wolfe-Simon noted. "It tells us this organism is doing something completely different."

Her latest discovery, however, moves possibilities to new levels.

"I think she is on to something. It says we should be looking for more than we are looking for," said Dr. Ron Oremland, who works with Wolfe-Simon at USGS.

"Basically, it's an alternate life form," said Larry Miller, a co-researcher at the USGS. "We are looking at something as alien as if it arrived on a meteorite."

In actuality, this new organism is probably quite old, and a product of Earth. One theory proposes that it could be a remnant from a much earlier biology that preceded our own, and failed.

"So, we have all these interesting implications," said Wolfe-Simon. "Maybe we are the second genesis of life on Earth. If it happened here, twice, perhaps it happened elsewhere once or twice."

Philosophically and scientifically, this is a major discovery that, if verified, could expand the biological playing field.

"I am curious with what my colleagues will respond with." admitted Wolfe-Simon, last summer. "This could be profound."