NASA's real news: bacterium on Earth that lives off arsenic!

By Phil Plait | December 2, 2010 11:12 am

[UPDATE (Dec. 7): The research outlined below is under very heavy fire from other biologists. I’ve written a follow-up post about it.]

[Update (13:30 MT Dec. 2): I misunderstood a part of this research dealing with arsenic when I read the journal paper, which was made more clear during the press conference. I have corrected the relevant text below, and struck through the old text. Hope this doesn’t confuse anyone, and sorry about that!]

NASA scientists announced today an incredible find: a form of microbe that apparently evolved the ability to use otherwise toxic arsenic in their biochemistry!

First off, just to be straight and to dispel the rumors: this is not aliens on Titan, or Mars, or anywhere else. This bizarre life form was found right here on good ol’ Earth. And don’t be disappointed: this is still pretty cool news.

Here are the critters in question:

bacteria_arsenic

Note the scale; a typical human hair is 100 times thicker than these beasties.

DM blogger Ed Yong of Not Exactly Rocket Science has written an in-depth and detailed account of all this as well. Highly recommended!

The bacteria (technically, the strain GFAJ-1 of Halomonadaceae) was found in Mono Lake, an extremely alkaline and salty lake in California near the Nevada border. And I do mean salty and alkaline: it has about twice the salt of ocean water, and has the incredible pH of 10 (neutral water has a pH of 7, and the pH scale is logarithmic; this means the lake water has the same alkaline strength as commercial antacids). Worse yet, the lake has a high concentration of arsenic, a deadly poison to many forms of life (including us). This makes the water toxic for most living creatures as we know them; for example there are no fish in the lake. However, there are algae, shrimp, and other such flora and fauna.

… including these new microbes. Dr. Felise Wolfe-Simon found them in the mud around the lake, and discovered that not only do they happily live with the arsenic that when subjected to high levels of arsenic in their environment, they actually incorporated it into their biochemistry!


Life like us uses a handful of basic elements in the majority of its biochemistry: carbon, hydrogen, oxygen, and nitrogen for the most part. But phosphorus is also a critical element in two major ways: it’s used as the backbone of the long, spiral-shaped DNA and RNA molecules (think of it as the winding support structure for a spiral staircase and you’ll get the picture), and it’s part of the energy transport mechanism for cells in the form of ATP (adenosine triphosphate). Without it, our cells would literally not be able to reproduce, and we’d be dead anyway if it were gone. There are many other ways phosphorus is used as well, including in cell membranes, bones, and so on. It’s a key element for all forms of life.

Oh, pardon me: all known forms of life up until now. In many ways phosphorus is chemically similar to arsenic (the latter is right below the former in the table of elements, a clear sign of chemical companionship). In fact, in very small amounts (and I mean like 50 parts per billion) arsenic may be important for life, but in larger amounts it’s incredibly toxic — there’s a terrifying litany of such attributes.

But these microbes in Mono Lake, at some point in their evolution, decided that if you can’t lick ‘em, join ‘em. They have somehow been able to utilize arsenic in the lake, using it instead of phosphorus in their biochemistry. To determine this, Dr. Wolfe-Simon took samples of the microbes, adding more and more arsenic while decreasing the amount of phosphorus in their environment to essentially zero. This would kill almost everything known to man, yet these little critters thrived. Even weirder, the bacteria were able to survive when either the phosphorus or the arsenic was reduced, but not both. So somehow, it’s able to use both of these elements as needed to survive.

Amazingly, using radioisotope-tagged molecules containing arsenic, they were able to find that the microbes incorporated the arsenic into their very DNA! It’s hard to stress how shocking this is; as I understand it, saying something like that to a microbiologist without evidence would’ve had them slowly backing away from you and looking for weapons or an escape route.

That is seriously freaky. So what does this mean in the scale of things?

For one thing, it means that life, as Jeff Goldblum so eloquently stated in "Jurassic Park", will find a way. It’s not clear at all how these bacteria were able to figure out how to utilize arsenic, but it’s not hard to imagine that understanding this will have all sorts of implications for biology, and perhaps even medicine.

And for another, it means that we need to be a little more open-minded when it comes to looking for life on other worlds. If a strain of bacterium this truly and awesomely bizarre can be right here under our noses — in California, for frak’s sake! — then what the heck will we find on other planets?

CATEGORIZED UNDER: Cool stuff, NASA, Science, Top Post

Comments (166)

Links to this Post

  1. A new life form was found! (Or, “THE ALIENS ARE HERE SOMEBODY FIND WILL SMITH”) | Digressions | December 2, 2010
  2. “The dollar bill in the couch.” « Communion Of Dreams | December 2, 2010
  3. NASA Finds Alien Life (Not Really) | Doug Cornelius .com | December 2, 2010
  4. NASA’s real news « One Guy and a Dream | December 2, 2010
  5. When life gives you arsenic, make arsenate-backboned DNA, non-alien Halomonadaceae! « Homologous Legs | December 2, 2010
  6. La biochimica velenosa della NASA « Il chimico impertinente | December 2, 2010
  7. Arsenic Consuming Microbes: Life Not As We Know It. | The Refined Geek | December 2, 2010
  8. I, For One, Welcome Our New Arsenic-Replacing-Phosphorus-In-DNA Overlords at Asymptotia | December 2, 2010
  9. An Interview With GFAJ-1, the Arsenic-Eating Bacterium « Unlikely Explanations | December 2, 2010
  10. After the hype. « Communion Of Dreams | December 3, 2010
  11. Friday Link Roundup #25 | No Forbidden Questions | December 3, 2010
  12. Link Salad, Dec. 3, 2010 at Literary Abomonations | December 3, 2010
  13. Astrobiology news conference follow-up | The Meridiani Journal | December 3, 2010
  14. Of Arsenic and Aliens | The Loom | Discover Magazine | December 5, 2010
  15. Quick Links | A Blog Around The Clock | December 5, 2010
  16. Arsenic Bacteria link-dump | A Blog Around The Clock | December 7, 2010
  17. Top posts in #Science according to Twitter user RTs (beta) « Emergent Hive | December 8, 2010
  18. ET found? - Page 5 - The Liverpool Way | December 8, 2010
  19. Arsenic about face | UmeedainTimes.com | December 8, 2010
  20. Fallout from Nasa’s ‘arsenic bacteria’ research | Story tracker | UmeedainTimes.com | May 13, 2011
  1. Toaster

    Hi Phil,

    You may wish to update the link to Ed Yong’s blog, it currently points to your Dr Who contest.

    Cheers

  2. allium

    (gobsmacked) – um, so is it still DNA, or just DNA-shaped?

  3. Christian Ready

    Hey, you blew the embargo by an hour! Now you’ve spoiled the surprise for the rest of us :) Seriously though, this is *amazingly* cool!

  4. Dave Thompson

    Do you know if it is in any way related to the arsenic-eating bacteria announced in 2008 from the same lake?

    http://www.newscientist.com/article/dn14537-arseniceating-bacteria-rewrite-evolutionary-history.html

  5. Thank you so much for clearing this up. My high school level biology education was not quite enough to grasp the magnitude of this discovery until I read this post. Thanks!!!

  6. Jeff C.

    Utterly incredible. I read this on a different source and didn’t believe it, so I came here to get it straight from an expert. Wow.

  7. The link to Ed Yong’s article appears to be wrong. Trying to bump your own stats? :-)

  8. James Leighton

    The greatest news of the 21st century.

    Nobel prize for them guys.

    I’ve been saying for years that to look for life on other planets based on our own was a stupid idea now some clever buggers has proved it right. I’m so happy :)

  9. Gabriel

    As cool as this is (and I freely admit that it is super-cool) I was really hoping that signs of alien life had been found on an exo-planet. I wasn’t even hoping for intelligent life just alien life. It makes since that it was found in California. California has always been on the leading edge.

  10. http://www.mazepath.com/uncleal/c_en01a.png
    Chemical & Engineering News 88(48) 4 (2010), 29 November 2010, Letters to the Editor, “Hungary’s Red Mud”

    Uncle Al offers a single brilliant solution to three huge-volume problems: aluminum production waste impoundment, ocean acidification, and Global Warming. Uncle Al suggests dumping Drano’s pH arseniferous iron oxide hazardous waste into the ocean AS A GOOD THING. When you need success in the worst way possible – Uncle Al’s way.

    Forbidden yesterday, mandated tomorrow.

  11. LWM

    Thank you, Phil, for not including in your account that “this changes everything we know about science” unlike other outlets.
    This is truly exciting news along with van Dokkum’s recent papers.

  12. @Allium Great question. As long as the chemical structure is still deoxyribose nucleic acid, it’s still DNA. It’s “just” the backbone that holds the bases together that has changed (from phosphate to arsenate). So I guess we can still call it DNA, but maybe we need a new nomenclature… DNAa vs. DNAp?

  13. “So somehow, it’s able to use both of these elements as needed to survive.”

    Huh. That’s unexpected. When I heard rumors about this, I figured phosphorus would be toxic to it in the same way arsenic was toxic to, well, everything else.

  14. James Leighton

    @Gabriel

    Me too but this make the possibility of life outside our own planet 100% and it means that it can be anything we can and cant imagine.

  15. Andy Beaton

    Awww crap. I was hoping for Life on Titan.

  16. Brian

    “It’s life, Jim, but not as we know it.” This is so much cooler than what I had predicted the news would be about.

  17. John Baxter

    Mono Lake and vicinity is a wonderful example of “development” gone sour–in this case City of Los Angeles water projects.

    A strawberry sundae, please, with arsenic sprinkles.

  18. It should be noted that arsenic-eating bacteria were discovered at Mono Lake a few years ago. The revelation today is how tightly they’ve incorporated the arsenic into their biochemistry.

    It should also be noted that phosphorus and arsenic are actually quite similar, being in the same column of the periodic table and all. It’s long been fodder for science fiction to have silicon-based life-forms, based on the similarities between silicon and carbon. Or likewise, to replace iron with copper in hemoglobin (hello, Mr. Spock!)… well, OK, maybe that last one isn’t so realistic, since copper and iron are not particularly similar.

    But the similarity would allow as to how these bacteria can apparently incorporate either arsenic or phosphorus into their DNA and ATPAs. Of course, similarity is not the same as being identical, and it will be very interesting to learn how the bacteria overcome the differences between P and As to be able to utilize either.

    None of this, of course, is meant belittle the discovery at all. Saying something is possible is light-years away from actually showing it exists. It’s a very remarkable finding; kudos to Dr. Wolfe-Simon and everybody else on the team. I’m very much looking forward to learning more.

  19. Navneeth

    5. Gabriel

    I was really hoping that signs of alien life had been found on an exo-planet.

    Srsly? (Or were you joking about that?)

    Just yesterday, there was that news about astronomers being able to guess for the first time with some observational evidence in the bag what is possibly making up the atmosphere of a Super Earth. Moreover, with a geobiologist leading the proceedings, I wouldn’t know how an exo-planet could have entered the equation.

  20. “For one thing, it means that life, as Jeff Goldblum so eloquently stated in “Jurassic Park”, will find a way.”

    Fascinating! I wonder, are they studying the arsenic levels of the algae and shrimp (and how they process it), or have they studied them just enough to know they exist in the lake? Regardless, this discovery has all sorts of possibilities!! Very cool.

  21. EJ

    Not exactly sure why NASA considers this astrobiology – last I looked Mono Lake is right here on Earth.

    While it’s an amazing discovery, color me skeptical about the implications for astrobiology – we’ve found all sorts of critters that can thrive in seemingly hostile and extreme conditions. Whether life could actually arise under those conditions seems to me to be a rather different question.

  22. I’m still hoping to find life forms in low orbit around Jupiter, trailing gossamer tendrils that draw energy from the planet’s immense magnetic field. But it’s always good to see that even on our own planet, biological life has plenty of tricks up its sleeve.

  23. James P Dehnert

    So, do we know if these evolved from a carbon based cousin, or are these truly unique? They either evolved from a carbon based relative, or they evolved on their own unlike any other known life as we know it. Either way this seems like one of the most clear cut cases of evolution. These clearly are not in anyones image, but they exist right here.

    Sorry if you think I am jumping the gun on this debate topic. This will be discussed, so you may as well put some though into it right now to be prepared.

    I cant wait to see what the folks at resistingthegreendragon(DOT)com will have to say about this!

  24. Mikey

    So, is this enough to suggest that these guys had a separate biogenesis event, or is it just an extremely harsh evolutionary jump from the same event as the rest of us?

  25. Naomi

    EJ @ 22,

    Yeah, it’s another example of an extremophile. But up until now, all of those extremophiles have used phosphorus, to the point that we would consider it to be an essential ingredient for life as we know it. To find an example of an organism that DOESN’T have to use it, and which can incorporate that into its DNA?

    Then yeah, it has implications for astrobiology. Our field of possible view has expanded – previously, an environment without phosphorus may have been overlooked, or arsenic-rich environments. Now we can look further. Slowly but surely, the range of environments that can support life is increasing.

  26. Jesper

    Wow!

    I’ve heard about the idea of a shadow biosphere before: life, right under our noses, but not life as we know it, made from the elements that all life until now is made of (mainly C, N, O, P, S, Ca).

    This is an amazing discovery that there is indeed life as we don’t know it, and right here on earth!

    Waiting for the NASA press conference… starting now!

  27. RL

    Maybe someone can clarify something (the linked discovery blog isn’t working for me). From the articles I read, the scientists took bacteria from Mono Lake and exposed the bacteria to arsenic repeatedly until the bacteria adapted (well, some did, the others died). While interesting, it seems that this is different than finding bacteria in CA that is already doing this. Am I missing something?

    I also read from another news account that not all biologists accept these findings since the structures with arsenic would be unstable with water. It may be just able to survive with really low levels of phosphorus. Verification to come.

  28. As cool as this is, arsenic is not a good substitute for phosphorus and so this is likely to be an isolated example. Part of the reason is basic chemistry; compared to the phosphate esters in DNA, arsenate esters are very unstable and are hydrolyzed remarkably fast. That makes this finding even more impressive, but it also precludes extensive substitution of arsenic for phosphorus in DNA-like genetic material.

  29. Sam H

    I was of course hoping for actual ET life like everyone else, but this is still insane. Life as we know it is broader than we thought. Life can change it’s very structure. Now I’m wondering how Answers in Genesis will deal with this one ;)

    (Speaking of which: they just announced plans for a theme park with a full scale replica of Noah’s Ark to be completed in 2014. This effort is backed by the Kentucky state governor).

  30. Oli

    Have fun with the Nobel prize, Dr. Felise Wolfe-Simon (=

  31. Well, I have always felt that scientists are too narrow in what they consider a livable space for alien life. However, I recognize the argument that if you open up to all possibilities you aren’t really looking for anything specific and probably won’t recognize anything.

    But I still see no reason that alien life should in any way correspond to our evolution of life.

  32. David P

    Wow this is just about 100 times more interesting than any information I thought they would release.

  33. James@24, these bacteria are still carbon-based. It’s phosphorus that they are (optionally) lacking, using arsenic instead.

  34. Tiredoffalsealarms

    Was going to do a blog post today BEFORE the NASA conference saying something to the effect of “I’m tired of NASA crying wolf”… that they should only “invoke” the extra-terrestrial life (microbes or anything else) when they’ve got something really truely amazing.

    Funny that the scientists name was “Wolfe”… so i’m not going to do the blog post, but does anyone else agree that these NASA “life” buildups hurt more than help.

    I wasted a whole hour of my life, that will never come back, all to see a microbe in a California lake?!

    I know the cost of bandwidth, and the cost of paying technicians to be on staff, so this “little” conference, together with the lost man hours of all the media covering this story, all the bloggers waiting for this story, all the youtube idiot speculators bloviating…. time=money!

    Millions either spent or lost waiting for this drivel of information… she (wolfe) sure seemed happy, but honestly, the first words of her speech said “I” and “ME”…

    I think I’m starting to see what, or “who” this little conference is all about.

  35. The Harvard chemist Frank Westheimer wrote a memorable paper explaining “why nature chose phosphates” which can be found here. It explains based on basic principles of chemistry why phosphates rather than arsenates or silicates have been chosen by life. Must read for those who think alternative life-forms could be common.

  36. Fenchurch

    I could have sworn I saw an episode of THROUGH THE WORMHOLE about these little critters, earlier this year. I might even still have the episode on my DVR, because I don’t ever delete anything, but I remember a woman with mud samples in jars, and doing things to them to change the colour. There was also something about something these being some sort of kickstart for life, and they demonstrated this theory by boiling the holy living you-know-what out of water until it became a nasty sludge.

  37. @dcsohl:
    “Or likewise, to replace iron with copper in hemoglobin (hello, Mr. Spock!)… well, OK, maybe that last one isn’t so realistic, since copper and iron are not particularly similar.”

    Not unrealistic at all… Hemocyanin is an oxygen transporting protein that uses copper instead of iron:
    http://en.wikipedia.org/wiki/Hemocyanin

  38. Quinlan Atkinson

    Ya know, just once I’d love for a smug, skeptical astronomer have to concede to a big freakin’ announcement from NASA that life does exist on other planets. There’s almost this religious level of dismissiveness that occurs whenever anyone has a sense of wonder about life being in other places. If your an academic, then your colleague will ostracize you – it’s “career suicide” they say! Instead it’s best, and perhaps “safer” for your career, to climb on the bandwagon and dismiss anyone else that believes in the existence of life beyond earth as just slack-jawed yocals.

    Oh well, I guess you all can keep studying dust particles and dark matter. At least that’s safer for your careers.

  39. So it replaces Phosphorus with Arsenic? Interesting.

    Back in the 1960’s Isaac Asimov wrote a science essay where he called Phosphorus “Life’s Bottleneck.” Nowadays the trendy term is “Peak Phosphorus.”
    Perhaps Arsenic life will replace Phosphorus life when Phosphorus becomes scarce.

  40. Matt

    Blogger Yong states: “It had replaced phosphorus in many important molecules including ATP and glucose (a sugar)”

    Last I checked glucose does not contain phosporus in the first place.

    Hmmm…..

  41. Hevach

    @19. dcsohl: Copper based hemoglobin isn’t unrealistic. It actually exists. It’s called Hemocyanin, and while it’s quite different from hemoglobin, it serves the same respiratory function by reversibly binding oxygen in the blood. It’s mostly seen in invertebrates, horseshoe crabs are one example.

    Also, it’s blue, not green.

  42. Navneeth

    36. Fenchurch,

    You remember correctly. It was Dr. Wolfe-Simon and Mono Lake.

  43. JSug

    @dcsohl #19:

    Or likewise, to replace iron with copper in hemoglobin (hello, Mr. Spock!)… well, OK, maybe that last one isn’t so realistic, since copper and iron are not particularly similar.

    You mean like many crustaceans, which use hemocyanin instead of hemoglobin in their blood?

    Darn. Scooped by Hevach.

  44. According to the Mono Lake Committee, the lake at the current level is almost three times as salty as the ocean. When/if the goal of 6392′ stabilzation level is reached, then the lake will be slightly more than twice as salty as the ocean.

    http://www.monolake.org/about/stats

  45. The news isn’t particularly new.

    Joan Slonczewski a biologist and science fiction writer wrote a book called “Brain Plague” with that premise in 2000, and various journal articles documenting bio-arsenic have been known as a scientific fact for at least as long. See, e.g. Niggemyer, A; Spring S, Stackebrandt E, Rosenzweig RF (December 2001). “Isolation and characterization of a novel As(V)-reducing bacterium: implications for arsenic mobilization and the genus Desulfitobacterium”. Appl Environ Microbiol 67 (12): 5568–80. doi:10.1128/AEM.67.12.5568-5580.2001. PMID 11722908, and Reilly, Michael (26 April 2008). “Early life could have relied on ‘arsenic DNA'”. New Scientist 198 (2653): 10. doi:10.1016/S0262-4079(08)61007-6. http://www.newscientist.com/channel/life/mg19826533.600-early-life-could-have-relied-on-arsenic-dna.html.

    Several papers on the subject were published in 2002 and 2003.

  46. Jochen

    I know I shouldn’t have peed into Mono Lake when I visited it 2008…
    Now I created life! Awesome!

  47. Mike O

    Years ago Mono Lake had much high water level and possibly an outlet and therefore less akaline. It would be good to know if the critters evolved as their inviroment changed and how long it took. If that is the case Life did find a way. Conservation efforts have prevented the lake from becoming dry. During the 1970’s it was a lot lower than today thanks to LA DWP. I don’t know if Arsenic is natural in the lake but the area does have a gold mining history that could have contributed the Arsenic in the last 150 years. I do know that the area is about the best there is in California to visit with Yosemite National Park 20 miles west of the lake.

  48. phunk

    This is less interesting than I had hoped for (a second abiogenesis), but still pretty cool.

  49. MNP

    Reminder to a layman, not a big deal. You can call that big dumb stupids if you like, but this is the kind of thing that makes people look at NASA and wonder why we aren’t in Star Trek yet–and why NASA is running around in California as opposed to another planet. Got to explain it in a more exciting way for the average person if you want funding.

  50. Jack Mitcham

    Curious Wavefunction:

    One of the panel members at the press conference noted that arsenic might be a poor “choice” to build life on Earth because of our high temperature, but at lower temperatures, the “instability” of arsenic might be GOOD for life to move reactions along.

  51. MartiniConQueso

    To be fair, it’s hardly the *weirdest* life form one is likely to encounter in California.

    Still cool though.

  52. NAW

    This is really cool. Though I can’t wait for the missquoted news casts of this.

  53. Yojimbo

    They have assimilated arsenic. We’re next! Resistance is futile.

  54. Costas

    Is there any indication for how long has this kind of life evolved there?

  55. Richard Wolford

    @Non-Believer

    Dead-wrong. Scientists only accept parameters for life that we know of and can test for. How do you test for unknown forms of life? Don’t build that strawman.

  56. Scott B

    Can’t say I see this is very shocking. We’ve been finding life finding a way to live in many environments we never expected. There’s still a big gap between existing life being able to adapt to use almost any source of energy available to conditions elsewhere being right for life to form in the first place.

  57. J.J.E.

    The teleogy, it burns!

  58. MadScientist

    This reminds me of a few decades ago when chemists were attempting to create a number of arsenic analogs to phosphorous compounds. One Australian chemist put out a challenge to create the arsenic analog of the chemical class known as “phosphols” – as he put it “if successful it will be the first artificial arsol”. Chemists did eventually succeed.

    @MikeO: Arsenic is very common in many areas on the globe (including quite a few places in the USA). If you have a deep water well, arsenic is one of the metals assayed. In some areas which are generally dry, rain causes leaching of the arsenic and the runoff from those areas can contaminate the water supply (and even exceed the amount permissible in drinking water). If there’s plenty enough arsenic below the surface (in the gold mines for example, many of which are presumably placers), odds are the lake has its own natural arsenic.

  59. Ratandeep

    A second abiogenesis would have been 1000 times more awesome than this, but still cool.

  60. Phil, I’m rather disappointed in you. You had a perfect opportunity to make an old lace pun. Slipping…

  61. kurt_eh

    One of those wierd coincidences of the Universe: Just last week, the episode of “Through the Wormhole” that featured Dr. Wolfe-Simon’s prior work on Mono lake aired on Canada’s version of Discovery World HD.

  62. CB

    @ James Leighton

    I’ve been saying for years that to look for life on other planets based on our own was a stupid idea now some clever buggers has proved it right. I’m so happy :)

    Meh. It’s one thing to say that alien life could be unlike ours, it’s quite another to say what it could be like and thus what we should actually look for. So I disagree that it’s stupid to look for life based on what we know can exist, and I don’t think this discovery disproves that. It would be stupid to assume life can’t be different from what we know, but that’s not the same thing.

    I think this discovery demonstrates the best way to go about the search for extraterrestrial life:
    1) Search for known indicators of life.
    2) Search for new ways life could exist to expand the list of known indicators.

    Besides, the main things we’re looking for at our early stage of searching are liquid water and organic molecules, which this finding doesn’t really change. If something completely unexpected pops up and waves, or eats the tires on our rover, or whatever, we’re not going to ignore it because it’s not on the list.

  63. Karl Silver

    You might want to stick to a topic you actually know something abut next time.

  64. Chris

    Maybe next they’ll find some Horta or Tholian creature living on Venus using silicon chemistry.

  65. MoonShark

    FYI, Ars Technica had a writeup with a little more technical detail than most coverage.

    I study chemistry, and don’t find the news horribly surprising. If we find something that can swap silicon for carbon or sulfur for oxygen, then I’ll be more shocked. But life is weird, and much of its success is due to its diversity.

  66. Michael Swanson

    A few hours before the official announcement, I was talking to a guy at work that said he was hearing about arsenic-based, extraterrestrial life being discovered in a California lake. I told him to hold off on that until NASA’s official release. Another coworker who overheard our exchange asked for details, and when I said that microscopic life was using arsenic in place of phosphorous, the first guy chimed in again. “Yeah, it may even be extraterrestrial!” So the second guy asked, “So, is it like a man?”

    Palm –> face.

  67. Well, life couldn’t possibly evolved to use arsenic. This is proof that there’s really extraterrestrial life, and that one of them sneezed into Mono Lake during a visit a few thousand years ago.

  68. Dave

    I agree it’s cool to have discovered a life form who’s chemistry is this different here on Earth. I’m not at all surprised by life adapting to its environment. It’s a big deal if you say so.

  69. John Powell

    Next you’ll be telling us they have acid for blood!

  70. KCS

    To Todd W. #62. Well, should we put on a new production? “GFAJ-1 of Halomonadaceae and Old Lace”. Too bad Cary Grant isn’t around anymore.

  71. Fedos

    Awesome, this is pretty much exactly what I thought the news would be. Except that I made the same assumption that Tree Lobsters did about phosphorous being poisonous to them.

  72. andy

    Well gosh the trolls are out in force on this one. Sadly enough that was the most predictable part of the whole thing.

  73. John Paradox

    I, for one, welcome our new arsenic based overlords.

    J/P=?

  74. Grand Lunar

    Coolness, Phil.

    Goes to show that life in it’s many forms still holds many surprises for us.

    Makes me wonder if there are life forms that make use of uranium or plutonium.

  75. l33t haxor

    Nice strikethoughs guys.

  76. RadarKinetic

    Ok, so if this discovery broadens our scope of “life” when we are searching for life on other planets and wanted to look for life that used arsenic in place of phosphorus what would be different about the arsenic based planet? Would it appear that much different from our own? would we be talking about an entirley new type of ecosystem or are we still looking for planets with liquid agua and a similar atmosphere?

  77. Big Al

    I’m waiting for the goose that can substitute Au for Ca in it’s eggshells.

  78. Tribeca Mike

    Cool discovery and thanks for the info. I recall a program on one of the science cables channels a couple of years ago that featured Dr. Felisa Wolfe-Simon’s research at Mono Lake. She was very impressive, and quite adorable. Here’s an article about her work from Astrobiology Magazine:

    http://www.astrobio.net/index.php?option=com_expedition&task=detail&id=3259

  79. Matt B.

    The use of the “life finds a way” quote from Jurassic Park is apt here, but in the movie itself I hated it, because it seemed to misrepresent evolution as producing mutations in response to environment, when of course it’s only the gene pool’s retention of mutations that happens in response to the environment.

  80. Nick

    According to data from the Mono Lake Committe, The lake water does have elevated Arsenic levaels of around 17mg/l (17 ppm). http://www.monobasinresearch.org/images/mbeir/dchapter3/table3b-2.pdf

    WHO drinking water standards limit permitted Arsenic to 10 ppb, so this water is 17,000 times over the limit.

    AT this level of available Arsenic, a tolerance to the otherwise poisonous element may have developed very slowly over time (normally tens to hundreds of millions of years, which is far longer than this particular lake has existed), or (more likely) the organisms that live in this lake might have been selected preferentially from those of Earth’s diverse biota that are more resistant.

    I wonder if the Shrimps and Algae have Arsenic-management mechanisms?

  81. Steve D

    As for Quinlan Atkinson (40), the “smug, skeptical astronomers” will concede life exists elsewhere when there’s actual evidence. What I’d like to see is for smug uninformed non-scientists to admit the scientists actually know more than they do.

    Now for actual science. I never paid too much attention to the backbone of DNA, but the ribose molecules are joined by PO4 tetrahedra. Know what else has tetrahedral units that bond by sharing apical oxygens? Silicon. Now silicon doesn’t have the energy-storage capabilities of P or As, but if all the PO4 does in DNA is provide structural support, maybe Si could replace some of the P?

  82. Al Viro

    FWIW, polyarsenic acids ought to get more stable as pH goes up, so high alkalinity might make it not so surprising…

    And of course, As abundance is considerably lower than that of P to start with. Just what kind of environment has become feasible now that we know that there’s an extremophile that can survive with high As/P ratios? An exoplanet where a lot more As than P is detectable from Earth? IOW, the astrobiological implications are nil.

  83. amphiox

    Last I checked glucose does not contain phosporus in the first place.

    Perhaps he was referring to glucose-6-phosphate, the activated form of glucose that participates in cellular metabolism?

  84. Daniel J. Andrews

    So next time there are high levels of arsenic in drinking water industry-backed politicians can say “We don’t need to regulate arsenic. It’s just bacteria food”.

    Not exactly sure why NASA considers this astrobiology – last I looked Mono Lake is right here on Earth

    Probably because many people consider California people to be from another world (heck, us Canucks think you Americans are from another world). :-)

    And I see amphiox has beat me to the glucose phosphorus point.

    Edit: Ed has corrected his account.

  85. macintologist

    This is a very interesting link to other possible types of blood systems, maybe ones that don’t use oxygen.

    http://www.daviddarling.info/encyclopedia/B/blood.html

  86. Nick (#85): Ah, thanks for that link. I tried to find info like that earlier, but all I was finding were the articles about this finding. :) I’ll put in a link to your comment at the top of the post.

  87. Pete

    As well, Mono Lake is one of the oldest lakes in North America, lying on the north end of the Long Valley Cauldera system in eastern California. Who knows what other secrets lie in this mysteriously magnificent part of the United States. That being said, tourists, please stay away from my California. (laughs)

  88. Chris Winter

    The comment I was responding to disappeared. I don’t know how to make mine do the same.

  89. @ Quinlan Atkinson #40:

    Ya know, just once I’d love for a smug, skeptical astronomer have to concede to a big freakin’ announcement from NASA that life does exist on other planets. There’s almost this religious level of dismissiveness that occurs whenever anyone has a sense of wonder about life being in other places. If your an academic, then your colleague will ostracize you – it’s “career suicide” they say!

    Uh….actually, it’s the UFO nutters who go on about that “career suicide” angle. Astronomers just patiently go about their business, waiting for evidence.

  90. @TribecaMike … At least Astrobio wasn’t so “fluffy.” And, it quoted a skeptic, too. That said, I’m still skeptical on the amount of flurrery I perceive. (And, no, I’m not alone; skeptical friends of mine have also noted this): http://socraticgadfly.blogspot.com/2010/12/bad-or-at-least-breathless-science-by.html

  91. Quinlan Atkinson @ #40

    Ya know, just once I’d love for a smug, skeptical astronomer have to concede to a big freakin’ announcement from NASA that life does exist on other planets.

    Except nothing like that was actually said in the big freakin’ announcement.

    There’s almost this religious level of dismissiveness that occurs whenever anyone has a sense of wonder about life being in other places.

    Scientists can, and often do, have a sense of wonder about the possibility of life existing elsewhere. Have you actually ever read Phil’s blog? Having a sense of wonder, however, does not mean a scientist must discard the notions of proper scientific inquiry. There’s little to no “dismissiveness” about the possibility of extraterrestrial life in the scientific community; such life just hasn’t been found yet. You’re criticizing scientists for not indulging in the type of wild speculation that the media has been indulging in regarding this NASA press conference.

    If your an academic, then your colleague will ostracize you – it’s “career suicide” they say! Instead it’s best, and perhaps “safer” for your career, to climb on the bandwagon and dismiss anyone else that believes in the existence of life beyond earth as just slack-jawed yocals.

    Many scientists and academics do proclaim their belief in the existence of extraterrestrial life, as I have said. They just don’t have the evidence to make a definitively factual assertion on the subject. So they don’t. Would you rather have astronomers running around, flapping their arms while mindlessly screaming “I believe! I believe!”?

    Oh well, I guess you all can keep studying dust particles and dark matter. At least that’s safer for your careers.

    Let’s say scientists did it your way – run around like idiots and loudly trumpet their beliefs in extraterrestrial life without evidence. All that would do is encourage the anti-science types who go around saying that scientists do no real useful work, that they’re crackpots who exist by fleecing research grants. No matter what scientists and academics do, they are going to irritate one segment or another of the general public that is ignorant about the work they do, and how they go about doing it. You are a good example of that ignorance.

    Since we’re talking about great distances and great costs here, the search for extraterrestrial life has to be done in very small steps, like the discovery announced at today’s NASA press conference. That you say scientists and academics should abandon the intellectually calming influence of healthy caution and skepticism and run around trying to appeal to the emotions of the media-spoonfed masses tells me you don’t understand a great deal about science. Leave the science to the scientists; people like you can be the ones writing the articles in the Weekly World News.

  92. Tribeca Mike

    Re #40 = isn’t it about time to retire the “science is almost, sorta, kinda, exactly like a religion” cliche? I for one have no faith in it. Besides, Phil’s commentary here is, as usual, all about “a sense of wonder,” which just happens to be the opposite of a dreary sense of superiority.

  93. Edwardson

    uh oh. It feasts on arsenic? Should hope no pathogen starts falling in love with iodine and other antiseptics we have

  94. Mark Hansen

    @Quinlan,
    Most of your critics have already covered your more egregious errors but…
    “…Oh well, I guess you all can keep studying dust particles and dark matter. At least that’s safer for your careers.”
    As noted above, a very high percentage of astronomers do believe in, at the very least, the possibility of life beyond our solar system. However, being human, astronomers also have to eat, pay bills, and do all the mundane things that everyone else does. This requires money. You make money by doing your job according to your job description. If that includes studying dust particles, but not chasing UFO reports, then so be it.

    @Tiredoffalsealarms,
    What you and others consider amazing may not always line up to your liking. This is known as “life”. Please try to enjoy your stay.

  95. Tribeca Mike

    SocraticGadfly — I’m just amazed that the NY Times couldn’t find a way to insert a mention of the groovy new trend of ping pong into their reportage. Can’t believe they left the yuppie angle out of this one.

  96. Messier Tidy Upper

    @60. MadScientist Says:

    One Australian chemist put out a challenge to create the arsenic analog of the chemical class known as “phosphols” – as he put it “if successful it will be the first artificial arsol”.

    So did that first artificial arsol go into politics law or banking? ;-)

  97. Messier Tidy Upper

    They mentioned this on the morning radio news show – apparently the much hyped announcement “sank like a stone” (their words not mine) and apparently people generally felt pretty deflated & underwhelmed by it.

    As new type of extremophile that does weird chemical things living with and off arsenic is pretty cool, sure, but it is hardly worth all the build up particularly as far as the non-scientific general public are concerned.

    The lead up speculation was fun but NASA does, I think, run the risk of “crying wolf” with this anti-climatic announcement and could well be the butt of a few jokes over this for the next few days.

    If NASA are going to have mysterious speculation building excitement generating press conferences then they do, I think, need to jusify the hype by announcing something *really* ZOMG!!!! BIG and significant that’s going to grab everyone’s attention and get everyone’s adrenalin levels up.

    Terrestrial extremophile bacteria, however exotic and clever and fascinating in their own right they may be (& they are) don’t quite cut the mustard on that score. They should have released this news in a better style without building up such expectations. Of course the media and more excitable bloggers have to take a lot of blame for this too.

    84. Matt B. Says:

    The use of the “life finds a way” quote from Jurassic Park is apt here, but in the movie itself I hated it, because it seemed to misrepresent evolution as producing mutations in response to environment, when of course it’s only the gene pool’s retention of mutations that happens in response to the environment.

    As always the book is better! ;-)

    @99. Cosmic Snark : Well said – & seconded by me. :-)

  98. Jack 99

    Messier Tidy Upper:

    Surely arsol based lifeforms would be expected living on Uranus?!

    More seriously, we humans already use in our own metabolism a number of alternative elements in novel ways. For instance, there is a selenium analogue of the amino acid methionine, thought to be an essential amino acid.

    I have not looked at the details yet but I thought the arsenic analogue of ATP was unstable and useless for energy storage. Has it been proven that these bugs actually do this or is it “just” in DNA?

  99. alfaniner

    Missed opportunity – subtitling this post “Arsenic and Old Lake”.

  100. Messier Tidy Upper

    @ ^ alfaniner & #109. Jack 99 : LOL! ;-)

  101. Jack 99

    My bad, I was thinking of selenocysteine, not selenomethionine.

  102. Anchor

    While this is unquestionably a very intriguing discovery in biochemical terms, I’m sorry, but I just can’t get quite as worked up as some (like Dr. Felise Wolfe-Simon) on what is almost certainly basically an example of biochemical adaptation on the part of an extremophile microbe. Biologists have discovered so many examples of bizarre adaptations employed by extremophiles that the novelty has worn thin. Arsenic competence and even arsenate respiration is already known in other organisms. That these extremophiles have this particular enhanced biochemical adaptation that in a pinch appears capable of substituting arsenic in lieu of phosphorus within nucleic acid and other important biopolymers and molecules doesn’t exercise my sense of wonder as much as, say, discovering that silicon or tin can perform the role of carbon.

    As Ed Yong correctly points out, “the angle being used to sell the story is that this might have implications for alien life. Of course, the results have nothing to do with aliens.”

    This finding does not in any way constitute a reason for thinking anything other than that Earthly microbes are more adaptable in biochemical terms than we thought. It might energize some to imagine how diverse extraterrestrial biochemistry might be, but GFAJ-1 is NOT an independently-evolved organism (it belongs to all the rest of us terrestrial critters on the same evolutionary tree) and it doesn’t tell us a thing about alien biochemistry. It doesn’t even tell us anything about alien life that might very well happen to employ the same basic ingredients that ours does. It’s just saying that some earth organisms can be pretty darned adaptable.

    We knew it already and we’ve got another example. Carve in another notch mark next to all the other notches we’ve already collected. Even Dr. Wolfe-Simon acknowledged she had performed the experiment specifically because she was interested in the question of the extent to which microbes may substitute arsenic for phosphorus.

    I also agree with Yong in this seminal passage in his post (which Phil links to in the above box):

    “The discovery is amazing, but it’s easy to go overboard with it. For example, this breathlessly hyperbolic piece, published last year, [an article published in Astrobilogy Magazine featuring the work of none other than Felisa Wolfe-Simon] suggests that finding such bacteria would be “one of the most significant scientific discoveries of all time”. It would imply that “Mono Lake was home to a form of life biologically distinct from all other known life on Earth” and “strongly suggest that life got started on our planet not once, but at least twice”. The results do nothing of the sort.”

    Yong is completely correct there, but he worries about something I’ve seen others worry about: “However, I can’t help but feel that the result will be a lot of disappointed people, who’ve been robbed of an opportunity to be excited about a genuinely interesting discovery.”

    That is only part of the problem. The other part is even more sinister. Having watched the news conference, and after reading some of the WOWs and !!!’s and assorted gee-whizzes here, I have to wonder whether breathless hyperbole is just really that contageous or an adaptative social response in which so many feign excitement without really understanding anything concisely, that the distraction of RAH-RAH robs them of an opportunity to be GENUINELY excited about a “genuinely interesting discovery”. And then some people STILL characterize this as “shadow life”, precisely as if they hadn’t read or understood a damned thing.

    I mean, man, whenever we DO come across genuine evidence of life elsewhere, if these sort ever got more excited in proper proportion to the authentic merit of the discovery, they’d all froth at the mouth and have heart attacks.

    Sheesh, but that conference was hard to watch…

  103. Messier Tidy Upper

    @30. Sam H Says:

    Now I’m wondering how Answers in Genesis will deal with this one

    I’m guessing badly – with denial and nonsense as usual. ;-)

    (Speaking of which: they just announced plans for a theme park with a full scale replica of Noah’s Ark to be completed in 2014. This effort is backed by the Kentucky state governor).

    Is that even legal – constitutional separation of Church & State & all?
    Or does that only apply to the United States Federal government? :-(

    ***

    PS. This news was headlining the ‘World News’ programme on SBS TV, Australia, introduced just now as :

    “NASA discovers a new form of life.” :roll:

    Umm .. well, that’s kind of true, I suppose but a bit misleading.

  104. Anchor

    #99 Cosmic Snark: refreshing, well done and finely-kicked ass.

  105. ggremlin

    Very interesting news, but the Media was leading us to believe that NASA was going to announce that the aliens were signaling for landing instructions. Like that wasn’t have done from the White House in prime time with the President grinning from ear to ear. :)

    Follow-up announce, Hollywood is remaking the Cary Grant classic for alien distribution, “Phosphorus and Old Lace”.

  106. Nigel Depledge

    The BA said:

    . . . the long, spiral-shaped DNA and RNA molecules . . .

    Sorry, wrong answer.

    First, a spiral is a 2-dimensional figure, a curve whose radius gradually changes. DNA forms a helix. More specifically: two anti-parallel helices. It also, occasionally, forms a triple-helix structure.

    However, that common conflation of helix and spiral (“spiral” staircases are really helical) is trivial compared with the real problem:

    RNA almost never forms a helical structure. Most commonly, RNA forms clover-leaf structures, globular structures and disordered strands. RNA is, in many ways, far more complex than DNA.

    This arises from the mostly single-stranded nature of the various RNA molecules that can be found in many cells. Single-stranded DNA only ever exists in nature in some viruses and during DNA replication. All animals, plants, fungi, protista, archaea, cyanobacteria and bacteria (AFAICT) use double-stranded DNA. The helical structure of DNA arises from the bonding of the two strands.

  107. Zoozie

    Huge news still! Though I had hoped for something like “Huge colony of nymphomaniac humanoid looking aliens found on venus”

  108. Nigel Depledge

    The BA said:

    It’s not clear at all how these bacteria were able to figure out how to utilize arsenic, . . .

    Actually, there’s a pretty obvious general hypothesis to use as a starting point.

    Many enzymes (proteins that act in biology as chemical catalysts) are pretty specific when it comes to discriminating their substrate from chemically-similar molecules, but many are not.

    It seems plausible that, at some point, this bug underwent a mutation in a critical phosphate-processing enzyme that would allow arsenate to serve the same function in that part of its biochemistry as phosphate. Maybe not very well, but perhaps adequately in an environment containing concentrations of arsenic that would be toxic to many of its competitors. Subsequently, any other mutation that served to widen the application of arsenate in its biochemistry would have been postively selected, to the point where it can now – apparently – use arsenate and phosphate interchangeably.

    I would venture to predict that, in an environment containing no arsenic and plenty of phosphorus, this bug is incapable of competing with most other bugs, i.e. ones that (almost) exclusively use phosphorus in their biochemistry and to which arsenic is toxic.

  109. Nigel Depledge

    James Leighton (15) said:

    this make the possibility of life outside our own planet 100% and it means that it can be anything we can and cant imagine.

    Not really.

    Life will almost certainly need a solvent that can dissolve a huge range of different substances. Nothing yet discovered comes close to water as a universal solvent.

    Life will almost certainly need to form a large variety of long-chain molecules, and no element or combination of elements rivals carbon for the ability to do this.

    Life will almost certainly need to form boundaries to contain and regulate its energy-production, replication and self-maintenance mechanisms. Given the two constraints above, there are not many viable alternatives to long-chain-non-polar-molecules-with polar-head-groups-in-a-polar-solvent.

  110. Nigel Depledge

    Dcsohl (19) said:

    Or likewise, to replace iron with copper in hemoglobin (hello, Mr. Spock!)… well, OK, maybe that last one isn’t so realistic, since copper and iron are not particularly similar.

    How about ruthenium instead, then? That’s just below iron in the periodic table.

  111. Jason

    XKCD’s take on the news

  112. scgvlmike

    Jason beat me to it– I was going to post today’s XKCD too!

  113. BCL1

    Sorry, while this is very interesting news, it is not all that impressive. If they found a more basic chemical substitution (e.g. silicon for carbon — which can’t be done by the way) that might be truely interesting and be related to major changes in the way life might develop on other planets, but arsnic for phosphorous? In the Book of Life, the implications are a footnote at most.

  114. Oli

    I thought spiders use copper instead of iron in hemoglobin?
    Guess I’m wrong then…

  115. pheldespat

    Well, this is not the strangest thing to happen in California, nor the first time Californians use weird substances in creative ways.

  116. Gary

    I find this discovery to be little more than a curiosity. Arsenic and phosphorus have the same valence number and under such extreme conditions as Mono Lake has, it’s not surprising that a bacterium might have evolved a way to exploit what’s available. These kind of discoveries pop up now that the tools are available to make them. Thirty years ago it was deep-sea vent communities that were the rage. Next year it will be something else. All this discovery really tells us is that there still are areas on the fringe of knowledge about Earth organisms that are as yet undiscovered. Excessive extrapolation to off-Earth implications is going too far and the squeeing about it is rather comical, actually.

  117. Katharine

    The Washington Post and probably several other newspapers already went overboard with it. People are postulating a ‘shadow biosphere’.

    The only thing I got from the paper was that these organisms were able to replace their naturally-occurring phosphorus with arsenic, which causes problems for them anyway by making them grow vacuoles.

    How does the growth of these vacuoles affect these bacteria?

  118. Jim

    Oli, spiders circulate hemolymph as well, so I’d imagine they use hemocyanin as well. I’m away from my reference books to confirm that, though.

  119. I agree with Fenchurch and kurt_eh: Through the Wormhole featured a segment about these bacteria. I remember clearly that they said the microbes incorporated arsenic in their DNA. I think Nasa is repeating the news just because of the publicity.

  120. Murff

    CNN Quick Vote poll (unscientific) shows 86% (61,000+) of respondants believe that life exists on other planets.

    That is why the teaser headlines are such a letdown to the public.

  121. Number 6

    John Kass from the Chicago Tribune has a funny take on all of this…

    “Scientific breakthrough or slimy alien menace?”….

    at…

    http://www.chicagotribune.com/news/columnists/ct-met-kass-1203-20101203,0,1400305.column

  122. Katharine

    Cursory research on Google indicates that the arsenic MAY be what’s accumulated in the vacuoles, suggesting to me that the arsenic may be tolerable for the bacteria but still deleterious.

  123. A couple of obvious questions I haven’t seen answered yet:

    1. These arsenophiles share a common ancestry with all other life, right?

    2. Was the substitution of arsenic for phosphorus in the DNA complete, or is there still SOME phosphorus in there?

  124. Messier Tidy Upper

    @122. Jason : LOL. :-)

    Of course as well as arsenic they could’ve added some white phosphorous for that extra flaming fizz! ;-)

    Indeed checking out this :

    http://en.wikipedia.org/wiki/Phosphorus#Precautions

    Organic compounds of phosphorus form a wide class of materials, some of which are extremely toxic. Fluorophosphate esters are among the most potent neurotoxins known. A wide range of organophosphorus compounds are used for their toxicity to certain organisms as pesticides (herbicides, insecticides, fungicides, etc.) and weaponised as nerve agents. … The white phosphorus allotrope should be kept under water at all times as it presents a significant fire hazard due to its extreme reactivity with atmospheric oxygen, and it should only be manipulated with forceps since contact with skin can cause severe burns. Chronic white phosphorus poisoning leads to necrosis of the jaw called “phossy jaw”. Ingestion of white phosphorus may cause a medical condition known as “Smoking Stool Syndrome”.

    It seems phosporus is also pretty nasty – if usually essential in trace amounts / compounds – stuff.

  125. Devon

    Amazing, read this hilarious take on NASA’s new discovery at: http://www.spellingchimp.com/2010/12/microbes.html

    Cracks me up!

  126. Nigel Depledge

    Gary (128) said:

    I find this discovery to be little more than a curiosity. Arsenic and phosphorus have the same valence number and under such extreme conditions as Mono Lake has, it’s not surprising that a bacterium might have evolved a way to exploit what’s available.

    I disagree. Not only do I think this is a fairly big deal, I also think it is rather surprising.

    These bugs are not merely tolerating the presence of a substance that is toxic to nearly all Earthly life, but they are substituting an element for a different one in the same group. Where else does that happen? Do you know of any instances of Si being used in place of C? Or of P in place of N? Or of S in place of O? I’ll grant that it may be possible, but I’ve never heard of it happening before.

    Besides, there’s a hell of a lot more to chemistry than mere “valence number”. Arsenic is a lot bigger than phosphorus, and the bug’s enzymes need to accomodate that bulk to be able to utilise As in place of P.

    More subtlely, the arsenate anions will be “softer” than phosphate anions, which will influence the way in which they participate in chemical reactions.

    You seem to be dismissing something rather remarkable without seeming to have any grounds to do so.

  127. Nigel Depledge

    James P Dehnert (24) said:

    So, do we know if these evolved from a carbon based cousin, or are these truly unique? They either evolved from a carbon based relative, or they evolved on their own unlike any other known life as we know it. Either way this seems like one of the most clear cut cases of evolution. These clearly are not in anyones image, but they exist right here.

    They are carbon-based. They seem only to be using arsenate in place of phsophate (which is remarkable enough, IMO). Since they can use phosphate too, I imagine that their DNA contains both arsenic and phosphorus.

    Judging from some of the other comments here, it is unclear whether this confers an adaptive advantage or if it is merely an unavoidable side effect of tolerating such high concentrations of arsenic (presumably they have other mechanisms for mitigating the toxic effects of arsenic).

  128. Messier Tidy Upper

    I think the arsenic adaptation could have evolved in something like this manner :

    http://www.youtube.com/watch?v=rj2w4DpWp6M&feature=related

    Is that conceivable? ;-)

  129. LittleJim

    #19 dcsohl;

    Copper-based blood is already real – Horseshoe crabs have been using it since the pre-cambrian

  130. Nigel Depledge

    Non-believer (32) said:

    Well, I have always felt that scientists are too narrow in what they consider a livable space for alien life. However, I recognize the argument that if you open up to all possibilities you aren’t really looking for anything specific and probably won’t recognize anything.

    But I still see no reason that alien life should in any way correspond to our evolution of life.

    The biggest difficulty with asccepting a very broad range of definitions for life is not so much “where do you look for it?” as “how do you recognise it?”.

    A significant benefit of looking for life that corresponds in some way to life as we know it here on Earth is that it is identifiable as life.

    Life that is based on something completely different from what we know as life is likely to be unrecogniseable to us.

  131. Nigel Depledge

    Curious Wavefunction (29) said:

    . . . compared to the phosphate esters in DNA, arsenate esters are very unstable and are hydrolyzed remarkably fast. That makes this finding even more impressive, but it also precludes extensive substitution of arsenic for phosphorus in DNA-like genetic material.

    Aha!

    So, these bugs almost certainly have DNA that is mostly phosphorus-containing, and they probably have a high mutation rate owing to the intrinsic instability of their DNA.

  132. Bill Nettles

    I haven’t read or heard the details, but did the good Doctor find ATA along with ATP in the cells, or was there only substitution in the DNA?

    Question previously asked @ 21 (Lisa) and 85 (Nick): what about the shrimp and algae and their arsenic survival skills?

    NASA thinks that astrobiology is their positive PR cow, but they keep stepping in the paddies. Oops, this is Earth-based microbial life; Oops we didn’t find life on Mars, just chemicals that could have been produced by microbes as one of the dozens of possibilities; Oops, we didn’t realize that elliptical galaxies have a higher percentage of M-class stars than spirals and we can’t explain it. Let’s talk about how many more “Earths” there could be, never mind whether an M-class star even has a habitable zone. I’m getting tired of PR statements; they play the game so poorly.

  133. Martin Vajsar

    I think this is a bit overdone. Yes, these critters prosper in an exotic environment, but they are certainly not the first creatures exhibiting such distinctness. There are microbes living in the undersea geysers in temperatures over 100 °C (212 F), microbes multiplying in very salty solutions or below the freezing point, and even microbes merrily going about their business inside nuclear reactors. In my opinion none of these environments is any less deadly to ordinary life than a caustic arsenic lake. All of these microbes must have altered out common biological wiring significantly to be able to prosper in such places on they evolutionary path. Interesting? Definitely. Exciting? Surely for someone. Astounding? Definitely NO.

  134. Anchor

    @#144 Bill Nettles, who says, “I’m getting tired of PR statements; they play the game so poorly.”

    Well, the BASIC problem is that they feel the need to play the “game”, not that they are playing it poorly.

    It’s been a pet peave of mine for decades: the emergence of ‘Public Outreach’ campaigns have been an increasing pain in the neck and have caused as many eye-rolling problems in ‘educating the public’ as they have allegedly solved precisely BECAUSE they look to the game-book of strategies employed by commercial advertisers and Hollywood…with increasingly hideous results.

    That is not and never has been the proper way to inform, excite, and inspire the public. If anyone doubts this, just look at how comparatively more scientifically literate, informed and inspired the public was on the value of scientific knowledge and research during the late ’50s and ’60s, when no such ‘public outreach need’ evidently ever existed.

    The “GAME” is all about gaining an advantage in SELLING something. Why does NASA or any scientific institution or university feel they need to SELL anything? Science education and inspiration isn’t some saleable product or property that needs selling. It’s just information and information is valuable as knowledge. If they can’t even get THAT simple point across, not only to the public but themselves, what makes the Public Outreach folks think they’ve got skilled and talented dibs on the ‘most effective way’ to inform and inspire the public? They have an effective way of selling their own reason for being in that position. Period.

    Science doesn’t need an agent to promote it. It sells itself as long as it isn’t pasteurized, homogenized and otherwise ‘popularized’ before the remaining tasteless sludge is shoveled down the consumer gullet.

    People naturally respond to authentic deeds, discoveries and accomplishments. They don’t need the braying carnival barker middleman huckster who thinks that repackaging the stuff in shiny paper will induce increased attention and sales. That’s the FIRST insult thrown at the public, and after decades of this baloney we today reap a harvest of a growing groundswell of distrust, denialism and anti-scientific passion that is unprecedented.

    Just because we left the business of informing the public to ‘experts’ who supposedly know how to market something.

  135. Skeptic As-hole

    I’m not sold on this. Really not sold on this and here’s why:

    1) The best As:P ratio they got was 7.3:1 in dry cell weight. They are using media with phosphate contaminants (~3 uM). The extremely slow growth rate (20-fold in six days; compared to E. coli roughly 20-fold in 90 min) suggests limted growth that is occuring from phosphate salvage.

    2) Their As measurements are unconvincing for ICP-MS. The dry weight of As was measured at 0.19% +/- 0.25 % over eight measurements. The error is bigger than the data. There are numerical fubars obvious in the paper – the ratio of As to P calculated from 0.19/0.019 (Table 1) shoud not be 7.3.

    3) There is no evidence that As is incorporated into functional DNA or RNA and that such As-nucleotide is competent in replication/translation. They have evidence that As is incorporated into nucleic acids. That’s a major leap from there to functionally competent DNA/RNA.

    4) Arsenate diesters are unstable in water. The hydrolysis rates for arsenate esters are 10,000 – 1,000,000 times faster than the corresponding phosphate esters. No stability; no genetic information. The notion that water is kept away is curious at best and the halmark of pathological science at worst.

    5) The available redox potentials for As can cause problems as As(III) and As(V) can cycle under physiological conditions… for example, anoxic lake bed sediment. Only As(V) has the tetrahedral geometry needed to mimic phosphate.

    6) It’s been known that arseno-ADP, the ATP analog, is not stable in water. Hydrolysis rates have been estimated at 70 min-1. To put that into context, the study of enzyme kinetics using arseno-ADP is challenging as the straightforward water hydrolysis reaction is far faster than any enzymic reaction. How do you get to arseno-DNA without arsenic analogs of ATP?

    7) Arsenic accumulation by plants and bacteria has been known for a long time. The organisms have been genetically engineered to sequester high levels of arsenic with the hopes that they can be used in bioremediation. Bacteria are known to generate polymeric material to sequester arsenic.

    It would be poor of me to bash this work so harshly without giving an alternate theory, so here goes. There is no As incorporation into canonical, functional DNA. The organism is generating garbage nucleic acid to sequester the arsenic and avoid the toxicity. The garbage nucleic acid is being partitioned into vacuoles and, thus, the cells get bigger. This theory fits the data presented without rewriting any biochemistry. Much as I would love this result to be true I can’t just throw out a whole bunch of very well established chemistry. In support of the authors, the Science paper is fairly muted and only really claims As incorporation into ‘biomolecules.’ The press conference, the media frenzy and the breathless acceptance of As-based life on the other hand… stink.

  136. Keith Bowden

    I’ve always preferred to call it 7.1 Digital Surround Lake (because neither Mono nor Stereo were good enough).

    “Not only is the universe stranger than we imagine, it is stranger than we can imagine.”
    – Sir Arthur Eddington

    Someone needs to write a science parody of “Arsenic and Old Lace.”

  137. AnarchoEpistemologist

    Hhhhmmmmm, life defying the boundaries of what scientists thought was possible? Not exactly news there huh?

  138. Hannes

    @Skeptic As-hole: good call !

    Especially the extremely slow growth rate is VERY informative.

    This only shows the ability of life in general to adapt to extreme conditions.

    I really like NASA, but they are in trouble with Obama. This is fund raising.

  139. Nigel Depledge

    Martin Vajsar (146) said:

    I think this is a bit overdone. Yes, these critters prosper in an exotic environment, but they are certainly not the first creatures exhibiting such distinctness. There are microbes living in the undersea geysers in temperatures over 100 °C (212 F), microbes multiplying in very salty solutions or below the freezing point, and even microbes merrily going about their business inside nuclear reactors. In my opinion none of these environments is any less deadly to ordinary life than a caustic arsenic lake. All of these microbes must have altered out common biological wiring significantly to be able to prosper in such places on they evolutionary path. Interesting? Definitely. Exciting? Surely for someone. Astounding? Definitely NO.

    I think you missed the point.

    We now have knowledge of many extremophiles that can tolerate environments that would be deadly to most other forms of life. Indeed, the most extreme thermophiles, for instance, cannot grow and replicate below a certain temperature. (But that’s nothing unusual – E. coli is pretty incompetent at 15 °C.)

    The news here isn’t an organism that tolerates a toxic substance. The news is that this organism has incorporated said toxic substance into its biochemistry.

    Now, IIUC, it is not yet clear whether (a) the incorporation of As into DNA is deleterious and the organism is merely tolerating its presence, or (b) the organism is equally competent with (say) 3% of phosphates in its DNA replaced by arsenates as with 100% phosphates. But this really could be a whole new branch of biochemistry, which is very exciting indeed.

  140. Martin Blaise

    Keith Bowden writeth: “Someone needs to write a science parody of “Arsenic and Old Lace.””

    The appallingly ignorant pseudoscientist Richard Hoagland called his 2-hour radio rant on the subject “Arsenic and Old Space.” It will come as no surprise to anyone here that very little of what he said had any contact with reality.

    Just in case anyone feels the need to cringe in real-time:
    http://www.coasttocoastam.com/show/2010/12/02

    …and here’s a rebuttal by “expat”
    http://dorkmission.blogspot.com/2010/12/tiny-bacterium-defeats-pseudoscientist.html

  141. AJ in CA

    @Skeptic As-hole: I find your ideas intriguing and I wish to subscribe to your newsletter :D

    Srsly though, you obviously have expertise on the subject that I don’t, but what you say makes sense to me, anyway. I’m going to have to throw my lot in with what others here have already said, that this (not the original research, but the embargo/press conference stuff) is attention-seeking by NASA, and it may end up blowing up in their face.

  142. Nigel Depledge

    Hmmm … having thought about this more and having re-read coment #150 (Skeptic As-hole) I now see that the press release is all mouth and no trousers. It would be amazing if they found functionally-active arseno-DNA, but this does not appear to be what they have found.

    It seems to be just another arsenic-tolerant microorganism.

    Maybe the arsenic is merely binding to DNA (after all, there’s plenty of scope for a variety of metals to interact with DNA).

  143. Bill Daley

    This is an amazing development that is bound to enlarge our vision of what is necessary for life. Just one concern: is the new bacterium being contained to prevent any harm from its ingestion by other organisms?

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