Good news: NASA discovers freaky deaky arsenic-based life form

posted at 4:23 pm on December 2, 2010 by Allahpundit

No, they didn’t find it in space. They discovered it somewhere even stranger and more exotic, the place from which all bizarre life forms originate: California.

If, per NASA’s breathless announcement a few days ago, you were expecting something even freaky deakier, try not to be too disappointed. This is still darned deaky. In a nutshell: Every last organism on Earth is supposed to contain six essential elements — carbon, nitrogen, oxygen, hydrogen, sulphur, and phosphorus, the last of which is essential for forming the framework of the DNA double-helix. From bacteria to blue whales, if something’s alive then it’s got the big six. No exceptions to that rule.

Until now.

On the tree of life, according to the results of 16S rRNA sequencing, the rod-shaped GFAJ-1 nestles in among other salt-loving bacteria in the genus Halomonas. Many of these bacteria are known to be able to tolerate high levels of arsenic.

But Wolfe-Simon found that GFAJ-1 can go a step further. When starved of phosphorus, it can instead incorporate arsenic into its DNA, and continue growing as though nothing remarkable had happened…

The DNA molecule is shaped like a spiral ladder. The “rungs” of the ladder are comprised of pairs of nucleotides, which spell out the genetic instructions of life. The sides of the DNA ladder, referred to as its backbone, are long chains of alternating sugar and phosphate molecules. A phosphate molecule contains five atoms: one of phosphorus, four of oxygen. No phosphorus, no phosphate. No phosphate, no backbone. No backbone, no DNA. No DNA, no life…

When Wolfe-Simon starved GFAJ-1 cells of phosphorus, while flooding them with arsenic, far more than enough arsenic to kill most other organisms, it grew and divided as though it had been offered its favorite snack.

The California lake where they found the GFAJ-1 has 700 times the level of arsenic that’s considered safe by the EPA, which raises a few possibilities. One: The bacteria is a true alien life form that’s capable of swapping out “essential” elements for whatever’s abundant in its environment. In that case, where’d it come from and how’d it get there? Two: The bacteria’s an Earth-based life form that somehow figured out one of the niftiest tricks in evolutionary history, altering the core structure of its own DNA to compensate for the loss of a key component. As an astrobiologist told the Times, “It’s like if you or I morphed into fully functioning cyborgs after being thrown into a room of electronic scrap with nothing to eat.” If it’s evolution at work, is it a new branch on the tree or … a whole new tree? And how many more branches are there on that tree? Read WaPo’s very user-friendly article on all this, suggesting the possibility of an entire “shadow biosphere” on Earth that doesn’t follow the usual biological rules.

Third possibility: Maybe the whole thing’s being oversold.

Steven Benner, a distinguished fellow at the Foundation for Applied Molecular Evolution in Gainesville, Fla., remains skeptical.

If you “replace all the phosphates by arsenates,” in the backbone of DNA, he said, “every bond in that chain is going to hydrolyze [react with water and fall apart] with a half-life on the order of minutes, say 10 minutes.”

So “if there is an arsenate equivalent of DNA in that bug, it has to be seriously stabilized” by some as-yet-unknown mechanism, Benner said.

Translation: Arsenic, while chemically similar to phosphorus, just ain’t rugged enough to keep the DNA matrix in place. It’s like trying to build a skyscraper out of wet sand instead of steel. Benner suspects that the bacteria isn’t using arsenic in its DNA at all but rather in other parts of the cell and that somehow there’s enough phosphorus in the lab cultures to keep it going. In fact, one of the scientists who spoke to the Times admits that there’s no hard proof yet that there’s arsenic in the DNA; the evidence is circumstantial, based on the fact that the bacteria were collected more than a year ago and starved of phosphorus ever since. The only amount available to them was the trace bits floating around in the original sample. Which means … maybe the real talent these bacteria have is subsisting, camel-like, for long periods on really small amounts of essential elements instead of swapping out those elements entirely.

Here’s Bill Nye, the science guy, to explain it all to you. My year’s quota of scientific wonkery posts is thus filled.


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Comment pages: 1 2 3

Yes certain parts of our behaviour may be genetically encoded, instilled by natural selection in our savanna-dwelling ancestors. But genes aren’t destiny….”genetic” does not mean “unchangeable.””

Zekecorlain on December 3, 2010 at 5:06 PM

yawn…meaningless darwiniac talking points…as usual…and gomer….no one ever said genetic means unchangeable…you’re setting up straw men cause you don’t have the intellect to defend your own theory…laughable.

right4life on December 3, 2010 at 6:16 PM

Something is seriously wrong with you gomer.

dakine on December 3, 2010 at 4:44 PM

really ducky?? at least I’m not a wacko atheist who has to lie and pretend to be a christian….what a loser!

oh and no christian would pull the BS you pulled. if you were a christian, or a man with any integrity, you would apologize for lying about me.

but you can’t….and your moronic drivel is amusing as hell…when clowns like you are upset by what I post, then I know I’m doing the right thing! LOL

right4life on December 3, 2010 at 6:18 PM

Something is seriously wrong with you gomer.

dakine on December 3, 2010 at 4:44 PM

oh and uh imitation is the sincerest form of flattery…but then its rather obvious you don’t have the intellect to come up with your own retorts!! loser!

right4life on December 3, 2010 at 6:19 PM

Zekecorlain on December 3, 2010 at 5:06 PM

hey gomer, ask old Jer to explain this one….

Some water fleas sport a spiny helmet that deters predators; others, with identical DNA sequences, have bare heads. What differs between the two is not their genes but their mothers’ experiences. If mom had a run-in with predators, her offspring have helmets, an effect one wag called “bite the mother, fight the daughter.” If mom lived her life unthreatened, her offspring have no helmets. Same DNA, different traits. Somehow, the experience of the mother, not only her DNA sequences, has been transmitted to her offspring.
That gives strict Darwinians heart palpitations, for it reeks of the discredited theory of Jean-Baptiste Lamarck (1744–1829

http://www.newsweek.com/id/180103

I look forward to your typical response: duhhh uhhh duhhhh….LOL

right4life on December 3, 2010 at 6:21 PM

that evolutionary theory makes predictions that are consistently borne out by the data

Zekecorlain on December 3, 2010 at 5:06 PM

list those predictions, gomer.

here’s a few that didn’t work out for old Charlie…

# The failure of evolutionary biology to provide detailed evolutionary explanations for the origin of complex biochemical features;
# The failure of the fossil record to provide support for Darwinian evolution;
# The failure of molecular biology to provide evidence for universal common descent;
# The failure of genetics and chemistry to explain the origin of the genetic code;
# The failure of developmental biology to explain why vertebrate embryos diverge from the beginning of development.

http://www.judgingpbs.com/

sorry Charlie!!! LOL

right4life on December 3, 2010 at 6:26 PM

right4life on December 3, 2010 at 6:26 PM

r4life, have you noticed that anti-theists call Christians stupid and uneducated, and then, after we clean their clock, call us “unChristlike” for standing up for ourselves?

It’s so predictable.

Grace_is_sufficient on December 3, 2010 at 7:14 PM

r4life, have you noticed that anti-theists call Christians stupid and uneducated, and then, after we clean their clock, call us “unChristlike” for standing up for ourselves?

It’s so predictable.

very true. they think they’re so smart…but they’re just legends in their own mind.

right4life on December 3, 2010 at 7:18 PM

I have in my decades as a news junkie seen and heard many so-called breakthroughs like this one that are supposed to change everything we know and/or do about _________________. Usually, sometime after the headline-grabbing press conference with the researchers breaking it all down for us in condescending (if not outright insulting) terms, skeptical colleagues from their field chime in, throwing cold water all over the former’s Norwegian dreams, and the whole thing dies down within weeks (if not days) in the public consciousness. Prime example: the “Cold Fusion Breakthrough” in 1986 that briefly spiked interest in palladium futures and was but a memory by the end of the next year.

My antennae went up when the woman who directed the arsenic experiment began by talking about herself more than the process. I ain’t no high-falutin’ fizzicist or nuthin’, but I can tell the difference between someone who is making an effort to explain a scientific concept to a layman and someone who is trying to get attention by flashing their education and expecting people to swallow it because they may not completely understand every aspect of the science involved. Fitting into that latter category: Al Gore.

L.N. Smithee on December 3, 2010 at 8:30 PM

Yay!

NASA discovers life on Earth.

catmman on December 3, 2010 at 10:20 PM

Wait! How can this discovery help facilitate a higher Muslim self esteem? Isn’t that the ‘new normal’ mission statement for NASA?

Perhaps NASA has indeed discovered the ‘shadow bioshpere’ of the earth…and it can be found in the Middle East….

Dick Turpin on December 4, 2010 at 10:16 AM

My year’s quota of scientific wonkery posts is thus filled.

Ah, good. This is the kind of stuff I really dig, but the comments that usually follow are pretty depressing.

Asher on December 4, 2010 at 11:08 AM

Update for anyone still paying attention.

fronclynne on December 6, 2010 at 6:57 PM

Comment pages: 1 2 3