Arsenic sits right beneath phosphorus in the periodic table of the elements and shares many of its chemical properties. Indeed, that chemical closeness is what makes it toxic, Dr. Wolfe-Simon said, allowing it to slip easily into a cell’s machinery where it then gums things up, like bad oil in a car engine.
At a conference at Arizona State about alien life in 2006, however, Dr. [Felisa] Wolfe-Simon suggested that an organism that could cope with arsenic might actually have incorporated arsenic instead of phosphorus into its lifestyle. In a subsequent paper in The International Journal of Astrobiology, she and Ariel Anbar and Paul Davies, both of Arizona State University, predicted the existence of arsenic-loving life forms....
Reasoning that such organisms were more likely to be found in environments already rich in arsenic, Dr. Wolfe-Simon and her colleagues scooped up a test tube full of mud from Mono Lake, which is salty, alkaline and already heavy in arsenic, and gradually fed them more and more.
२ डिसेंबर, २०१०
"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."
The newly discovered arsenic-eating bacteria. But it's not really that weird:
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Most importantly, we can figure that phosphorous is to arsenic based alien life forms what arsenic is to life that incorporates phosphorous.
Poison.
For most of our planet's history there was life. However, for about 75% of that time life was single cell sludge.
Life, complex life and intelligent life aren't the same things.
There could be pond scum on Titan and it won't matter to us very much.
Sure, everyone will get excited for a while, but then we'll just go on with our lives. The universe is already full of amazing things that we are very good at ignoring.
The universe is already full of amazing things that we are very good at ignoring.
Ain't that the sad truth.
This is still pretty cool though.
Another day, another evolution "miracle". But what force directs these scrap parts to form a totally different electronic tool. That would require an intelligent computer geek. But this theory may soon be tested when Juliene Assange starts to eat his new arsenic diet. It's not for nothing that Kings all had a food taster to partake in their sight some time while before they ate dinner.
"...already heavy in arsenic, and gradually fed them more and more"
Reverse homeopathic.
and in a related note:
Astronomers triple estimate of stars, think trillions of Earths may exist
This is really being blown out of proportion by some people. It's worthy of a footnote in a biology textbook at most.
I think that this increases the chance that there actually is pond scum on Titan and junk growing beneath the icy crust of Europa.
I think that it does matter to us, very much, if it turns out that life becomes the rule rather than the exception.
Speaking of bad oil -- we are, aren't we? -- Wanna hear something ridiculous? I had my oil changed last week. The guy goes, "High mileage, medium mileage, or low mileage?" I answered, "Oh, low. Very low, " because I drive the vehicle hardly at all. But the question was to know to the mileage on the vehicle, not how much it is presently driven, so my answer was the opposite to the point of the array of choices. I trust the gents have the good sense to know better.
Sounds like what the Left wants for this country.
@ sunsong
An Earth-sized planet orbiting a red dwarf star would be unlikely to have Earth-like conditions. Just to have temperatures suitable for liquid water, the planet would have to orbit its parent star very closely indeed, close enough to be in tidal lock, just like the Moon is in tidal lock with the Earth. One known example of a Earth-like planet orbiting a red dwarf sun is Gliese 581d, which is five times closer to it parent than Earth is to the Sun. A "year" on Gliese 581d is only 37 days. Though water could exist on 581d, it's not likely to be friendly to complex organic life.
@Synova:
Most importantly, we can figure that phosphorous is to arsenic based alien life forms what arsenic is to life that incorporates phosphorous.
Poison.
Not from this research. This bacterium can substitue arsenic for phosphorous to some extent.
@Jason:
This is really being blown out of proportion by some people.
Science journalism drives me to despair. I've heard it referred to as entirely new life, life unrealted to life on earth, and life not based on DNA. None of those are true.
@Synova again:
I think that it does matter to us, very much, if it turns out that life becomes the rule rather than the exception.
I agree. It becomes much harder to talk about "the privileged planet" and other anthropomorphisms.
For some reason, the good folks at the Discovery Institute have spent a lot of pixels to say that life won't be found elsewhere in the universe. To me that sounds like an unforced error. Surely God (oh all right "desginers") could create life wherever or in multiple places--why stake out a position on this when it's not necessary?
The reason, of course, is that the "designer" is the God of Abraham and the Di won't contradict the script laid in His book, regardless of the science. Humankind has to be the most important thing in creation. If God made life everwhere, then we're not special and we might as well have evolved.
This should have an "evolution" tag.
Astronomers triple estimate of stars, think trillions of Earths may exist
I hope it is more than that. If there are 1 trillion earth-like words, that means that there is only 1 per 300 billion stars. Which would mean that we're probably the only one in the Milky Way galaxy, and we can forget about ever even seeing one, let alone visiting it.
In fact, if they are that rare then I don't know how we would ever confirm that they exist at all.
"But it's not really that weird"
Indeed not--some of them have been commenting here for quite a while already.
wv: noolyze -- Monsanto's brand of genetically-engineered arsenic-eating bacteria.
If there are trillions of earths listening in to our signals, then we definitely need more cable channels so they won't get bored, bless their little arsenic souls.
"But it's not really that weird"
Actually, it is that weird, and it is a big deal. It won't change your everyday lives one whit, but neither does relativity. I have not yet read the paper, so I'm going on secondhand accounts. My initial reaction was "they found something that lives in arsenic; how anticlimactic." Upon further review, it appears they have forced it to use arsenic in place of phosphorus. From the abstract, they imply arsenate has mostly replaced phosphate in this mutant strain, both in nucleic acids and in phosphoproteins. If this pans out, it is quite spectacular from the standpoint of a biochemist. I would love to get my hands on this critter's topoisomerases. Examining that alone would keep me busy for the rest of my career. Anybody that studies anything that interacts with phosphate-based DNA ("normal DNA") now has a new system to play in, and that's a lot of people. The very fact that it functions with arsenate-based DNA is huge. Yes, it's still DNA-based life, but the DNA in question is significantly different than anything we've ever seen.
IDK, I decided a long time ago that life is probably pretty common.
Growing up, people used to argue about whether other stars even had planets.
The universe is a big, big place and it seems to me that our planet isn't special at all.
It also seems to take a long, long time for life to get past the scummy soup stage.
So, it seems to me, life is probably common, but anything more than scum is much more rare.
Since the universe is big, that probably means that complex life (that is, life with tentacles and stuff), is probably far away.
Tentacle critters that also have brains are even more rare. It took a really, really long time for us smart people to evolve. So, in my own little Drake equation (which has as much actually data as the original) intelligent life exists somewhere else, but is verrrry far away and most likely we'll never meet.
The metaphysical consequences of any life anywhere else are pretty profound, but if you think about it it's not very different than life in extreme environments on earth.
We can't live underwater, but most life is in the ocean. So... isn't that odd? I find out weird things about new species all the time just watching NatGeo with my five year old. And since that is like .00000000001% of what's out there on this one planet... that's amazing.
Since other rocks in space are mostly like our rock in space, it's not really that big a leap for life to be elsewhere. The universe is simply very big.
The size of the universe doesn't really change the big questions in human life, like what we are here for, or what we are supposed to do, or why people can be evil. Simply finding life somewhere under a rock doesn't change that. It's cool, but it doesn't change people.
Its not all that surprising that the alien (or not before known) bacteria was found in California ;)
So.. if we ever go to an arsenic based planet.. we would have to bring our own food?
Just saying.
I think the significant thing here is that arguably the two most important chemical processes for life as we know it is tougher than I think anyone imagined. DNA transcription and the ADP/ATP engines (in Krebs and Calvin variations) are less fragile than I think most scientists imagined they could be.
Someone called me about this earlier today and said that it sounded neat, but that they couldn't actually be sure that it was arsenic and not trace amounts of phosphorus. I can't find the article the person was talking about. Anyone see anything like that?
“I would be really surprised if the bugs they’ve isolated actually incorporate arsenic into any of their key biomolecules as a substitute for phosphorus (in, for example, DNA or ATP) – I suspect that what they’ve got is a bug that is simply tolerant to the high arsenic concentrations, or possibly uses it somehow in its metabolism.”
Thanks, Meade.
@Meade:
Your link was to a comment made before the release--this bacterium DOES subsitute arsenic for phosphorus in its DNA.
http://www.sciencemag.org/content/early/2010/12/01/science.1197258
From the Science article:
We used radiolabeled AsO to obtain more specific information about the intracellular distribution of arsenic. We observed intracellular arsenic in protein, metabolite, lipid and nucleic acid cellular fractions. Stationary
phase cells incorporated approximately a tenth of the total intracellular AsO4 label into nucleic acids but more than
three quarters of the AsO into the phenol extracted “protein” fraction, with a small fraction going into lipids. We caution that the large “protein” fraction is probably an
overestimate, as this extraction step likely contains numerous small, non-proteinaceous metabolites as well.
So I'm guessing Lake Mono is not exactly a popular vacation destination.
Thanks, GH. Amazing!
The alleged DNA fraction is also likely to contain other stuff.
Based on the published experiments I don't believe that there is arsenic in the DNA, and I am kind of appalled that this made it into Science.
Bad science?
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