Thursday, December 2, 2010

Arsenic and Old Science: NASA and Extraterrestrial Life

The Lemming doesn't know what it is about the science folks at FOXNews and Saturn - but today's article has a name in the byline: also an update on NASA, extraterrestrial life, and looking for a quarter in the yard.

No, really: that last phrase makes sense, in context.

"Are Aliens Among Us? Sort of, NASA Says"
John Brandon, Science, FOXNews, (December 2, 2010)

"Alien life has been among us all along, according to new biological findings announced by NASA Thursday.

"Research conducted by biochemist Dr. Felisa Wolfe-Simon from the U.S. Geological Survey has turned the quest for alien life on its ear, suggesting that phosphorous[!], carbon, and the other fundamental elements found in every living thing on Earth aren't the only signs of life. Wolfe-Simon will explain the findings at a hotly anticipated NASA press conference today at 2 p.m.

"After a two-year study at California's Mono Lake, near Yosemite National Park, Wolfe-Simon found that a bug will grow in the presence of the toxic chemical arsenic when only slight traces of phosphorous are present. It's a radical finding, says molecular biologist Steven Benner, who is part of NASA's 'Team Titan' and an expert on astrobiology -- forcing the space agency to redefine the quest for other life in the universe.

" 'When we're searching for alien life, if it's not a Ferengi from Star Trek, what would it be?' Benner asked FoxNews.com. In his estimation, we've always defined life as something that has the exact same chemistry as a life-form on Earth. The new discovery will likely change that equation, because it means the basic building blocks of DNA are not quite what we thought...."

So far, so good. Biologists are learning quite a bit from studying extremophile - critters that live in places that most other plants, animals, bacteria, fungi - and so on - can't survive in.

There's more to the article, including these quotes:

"...'It's a paradigm shift,' says Dimitar Sasselov, an astrobiologist who leads the Origins of Life Initiative at Harvard University. 'The possibility that Earth-life biochemistry is not universal is a transformational concept. It fills the search [for alien life] with optimism. NASA is moving in a good overall direction. What is needed is to take alternatives for life's chemistry to heart and fund research work better.'

"Arsenic is poisonous to nearly all forms of life on earth. Even small amounts of the poison become embedded in living tissue, causing liver failure and ultimately death -- in nearly everything BUT these bacteria...."

Nit-Picking by the Lemming

Good grief. This article was presumably done by a 'science' reporter. Well, he was probably educated in America.
It's Phosphorus, not "Phosphorous"
"Phosphorous," that multivalent nonmetallic element of the nitrogen family, spelled "phosphorus"
Arsenic, Phosphorus, Livers, and Life
Arsenic is bad for us because we've got livers - and arsenic is not good for the liver. Or the rest of us. It's chemically similar to phosphorus - and I'll get back to that. Plants don't have livers - and arsenic isn't particularly good for them, either. Again, it's a chemical thing. (National Institutes of Health)

Like just about everything else (November 22, 2010), there's a little bit of arsenic in all of us - it doesn't start being a problem until there's too much. One of the reasons arsenic in plants is studied is because the stuff was used to kill boll weevils. (Dartmouth Toxic Metals Research Program) And the Lemming is getting off-topic.

Looking for a Quarter in the Yard

The Lemming said that looking for a quarter made sense, in context. Here's the context:

"...science fiction author Robert Sawyer told FoxNews.com, there could be even more profound implications. We have always looked for alien life that matches our biology, but now we have found a different life-form that uses arsenic in its basic DNA structure, he said.

"Sawyer explained that NASA science probes have always looked in the most likely places we thought life could exist -- on Mars or Europa, a moon of Jupiter. There is an old joke, he says, about how someone lost a quarter in their garage, then looks out in the yard for it. A neighbor asks why they are looking there instead of in the garage; the light is better, he answers.

" 'We tend to use the tools we know and the places we know to look for alien life,' Sawyer said, explaining that humans want to find a walking, crawling alien and not one that just has different DNA...."
(FOXNews, emphasis mine)

What is it about Saturn?

The Lemming doesn't know what it is about the folks doing science news at FOXNews and Saturn.

Here's a somewhat non sequitur reference to Saturn:

"...Benner, said the arsenic-loving organism at Mono Lake grew without high levels of the nutrient phosphate (although some phosphates were still present). Just as important, it could change how we look for alien life on other planets, especially on Saturn and the moons of Jupiter...."

NASA's feature - I'll get to that in just a bit - doesn't mention Saturn. The gas giant isn't - outside of some fairly imaginative science fiction - near the top of the list for places we're looking for life.

Titan orbits Saturn - and that's another topic. (December 1, 2010)

NASA, Arsenic, and the Search for Life

"NASA-Funded Research Discovers Life Built With Toxic Chemical"
NASA (December 2, 2010)

"NASA-funded astrobiology research has changed the fundamental knowledge about what comprises all known life on Earth.

"Researchers conducting tests in the harsh environment of Mono Lake in California have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism substitutes arsenic for phosphorus in its cell components.

" 'The definition of life has just expanded,' said Ed Weiler, NASA's associate administrator for the Science Mission Directorate at the agency's Headquarters in Washington. 'As we pursue our efforts to seek signs of life in the solar system, we have to think more broadly, more diversely and consider life as we do not know it.'

"This finding of an alternative biochemistry makeup will alter biology textbooks and expand the scope of the search for life beyond Earth. The research is published in this week's edition of Science Express.

"Carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur are the six basic building blocks of all known forms of life on Earth. Phosphorus is part of the chemical backbone of DNA and RNA, the structures that carry genetic instructions for life, and is considered an essential element for all living cells.

"Phosphorus is a central component of the energy-carrying molecule in all cells (adenosine triphosphate) and also the phospholipids that form all cell membranes. Arsenic, which is chemically similar to phosphorus, is poisonous for most life on Earth. Arsenic disrupts metabolic pathways because chemically it behaves similarly to phosphate.

" 'We know that some microbes can breathe arsenic, but what we've found is a microbe doing something new -- building parts of itself out of arsenic,' said Felisa Wolfe-Simon, a NASA Astrobiology Research Fellow in residence at the U.S. Geological Survey in Menlo Park, Calif., and the research team's lead scientist. 'If something here on Earth can do something so unexpected, what else can life do that we haven't seen yet?'

"The newly discovered microbe, strain GFAJ-1, is a member of a common group of bacteria, the Gammaproteobacteria. 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. Subsequent analyses indicated that the arsenic was being used to produce the building blocks of new GFAJ-1 cells.

"The key issue the researchers investigated was when the microbe was grown on arsenic did the arsenic actually became incorporated into the organisms' vital biochemical machinery, such as DNA, proteins and the cell membranes. A variety of sophisticated laboratory techniques was used to determine where the arsenic was incorporated...."

Now that's interesting. Also spelled correctly, and without any irrelevant mentions of Saturn. Or Ypsilanti.

Related posts:More related posts, at
The title of this post? "Arsenic and Old Science..."? Arsenic and Old Lace is a 1944 Cary Grant comedy. That has nothing to do with extraterrestrial life. Or Saturn.

2 comments:

Brigid said...

Misplaced return: "Saturn. Or
Ypsilanti."

The Friendly Neighborhood Proofreader

Brian, aka Aluwir, aka Norski said...

Brigid,

Oops! Fixed it! Thanks!

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