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Get Your Biology Textbook...and an Eraser!
December 2, 2010 / Posted by: Aaron Gronstal
Geomicrobiologist Felisa Wolfe-Simon, collecting lake-bottom sediments in the shallow waters of Mono Lake in California. Wolfe-Simon cultured the arsenic-utilizing organisms from this hypersaline and highly alkaline environment. Credit: ©2010 Henry Bortman
One of the basic assumptions about life on Earth may be due for a revision thanks to research supported by NASA’s Astrobiology Program. Geomicrobiologist Felisa Wolfe-Simon has discovered a bacterium in California’s Mono Lake that uses arsenic instead of phosphorus in its DNA. Up until now, it was believed that all life required phosphorus as a fundamental piece of the ‘backbone’ that holds DNA together. The discovery of an organism that thrives on otherwise poisonous arsenic broadens our thinking about the possibility of life on other planets, and begs a rewrite of biology textbooks by changing our understanding of how life is formed from its most basic elemental building blocks. Astrobiology Magazine has the story.Wolfe-Simon’s research is supported by NASA’s Exobiology and Evolutionary Biology (Exo/Evo) Program and the NASA Astrobiology Institute. Among the goals of these programs is determining the evolution of genes, metabolic pathways, and microbial species on Earth in order to understand the potential for life on other worlds. Wolfe-Simon’s discovery represents the first time in the history of biology that an organism has been found to use a different element to build one of its most basic structures. The paper appears in today’s issue of “Science Express“ and will subsequently be published in the journal Science.
Source: [NASA]
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- Exposing Organics on the ISS
- A Slow Death in the P-T Extinction
- An Alternative Path for the Evolution of Nitrogen Fixation
- A New Pathway to Life's Origin
- Ground Truth
- 2012 Astrobiology Graduate Student Conference
Joel A. Francis said:
I’m certainly no expert, but I’ve heard it argued that the nuclear instability of phosphorus over long periods of time is one reason why panspermia is unlikely — that any DNA would not be able to survive the long trip intact. I wonder what the stability is of a DNA-like molecule with phosphorus replaced with arsenic over the time scales necessary for panspermia.
Alex Martin said:
My congratulations to Felisa and all who worked on this amazing discovery.
Cheers from Barcelona!
Jack Llewelyn said:
I am not surprised at this finding but very pleased that Felisa Wolfe-Simon has taken our understanding of basic biological structures to another level with her proofs and research. Looking forward to reading much more in A M. et al, Meanwhile, keep on searching! and thanks Felisa.
Charles Ivie said:
This remarkable discovery lends support to the idea that life based on other chemistries is possible. This opens the door to new concepts in life detection and even the definition of life its self. It also raises the question regarding substitution of other elements in the DNA and protein molecules. Is the arsenic for phosphorous substitution the only one possible or are there others? The old SciFi idea of silicon based life forms may be closer to reality than we think.
It is one thing to discuss “Life as we Know it” quite another to think about “Life as we Don’t know it”. Great work. Kudos to Felisa and her team. Very impressive.
Jason said:
It’s life Jim. But not as we know it.
emre yener said:
congratulations to Felisa and rest of the team for their outstanding discovery!
I am pretty sure that mr. Craig Venter will not going to sleep tonight!! well done….
All the best.
Samantha said:
As told by Isaac Asimov !!! Master! :)
Nigel Straightgrain said:
The fact that this discovery (which is significant in its own right) is hailed as something that might change the “definition of life” simply makes more conspicuous the fact that no such definition actually exists. If a proper definition did exist, this discovery would not change it—indeed, could not change it.
This is the tragedy that out-of-control reductionism’s monopoly stranglehold on scientific epistemology has engendered. Life will never be defined in terms of its fractionated, constituent elements. The answer to the question, “What is life?” is not at the molecular or atomic levels.
Physics and chemistry are wonderful sciences—very effective in their respective domains. And, to be sure, all biological systems are constrained by physical and chemical laws and principles. But they can’t tell the whole story; they are the wrong tool for the job…sort of like using a bobcat to tune a piano.
Until the biological sciences recognize that they are not a special case of physics, and they learn how to incorporate concepts like function, process, relation, and context into their models, discoveries like this one will remain orphaned, disembodied factoids that await integration into the bigger picture. I don’t believe we can see that picture while our heads are buried in the periodic table.
John Hunter said:
Absolutely fantastic work. Thanks for using some of my tax dollars so well. Keep up the good work.
Robert K. Gieseler, Ph.D. said:
This most remarkable finding may only be surpassed by two facts, i.e.,
(i) That this life-form was not outcompeted by the supposedly massive selection pressure exerted by those life-forms whose genomes have a phosphorus backbone, and
(ii) That its genome still is a variant of DNA rather than some other kind of polymer that enables to conserve genetic information.
Thus, as always, once a new answer is given many new questions arise.
Most sincere congrats from Germany to Felisa and everybody else involved in arriving at this true milestone finding.
Michelangelo said:
I can’t believe this, even ATP……
Paul D. said:
Congratulations for this important discovery! Greetings from Guatemala.
Daniel Campbell said:
@ Joel A. Francis. I’m not sure what you mean about nuclear instability. Phosphorus is stable:
http://en.wikipedia.org/wiki/Phosphorus
Jeff Magella said:
The phase “game changing” is used much too often, but in this case, it applies.
Steven E. Streight aka Vaspers said:
LIfe based on other chemistries, or no chemistry at all, and what about all astral bodies (comets, stars, moons, planets, black holes, HIggs bosons, etc.) being living entities, with quasi-biological life cycles and aims?
Anyway we now have to assess the predictability of this nuance as life potential in the universe.
Congratulations for this discovery and tentative explanation. Science has only begun to explore anything, we have vast plethoras that are still Total Unknowns.
Good job. Proud to be a human today.
Str8 Sounds
Renato said:
You make History today !!
Congratulations from Rio de Janeiro – Brazil !!!
Gabriele Foresti said:
Only to say my congratulations to Felisa Wolfe-Simon and her team for this big discovery!
Stein Fjellseth said:
My biggest congrats to Felisa Wolfe-Simon and her collegues! I love when new discoveries are made and I believe that many more discoveries will be made in the future! I myself studies another field that is extremely interresting and that is quantum physics and what humans are capable to transform in their bodies concerning bodily functions and sickness. I suffer from rosacea and tinnitus and my theory is that if I can change the information In my skincells, I can change my cells appearance and by doing so create perfect cells without a trace of Rosacea. I believe this can be done through a combination of meditation and focused intention. Any comments about this will be highly appreciated. Send your comments to: http:://pushme.to/livewithpassion and I will later publish my results and if you state name and emailaddress, I will keep in touch and we can exchange thoughts about the subject. I have by using focused intention already erased sickness like flu and all mental illness from my vocabulary and hasn’t been sick for ages. I’m also studying how we can reverse or stop the aging process! Thank you so much for taking your valuable time to read this! Hope to hear from you! Greetings from Stein In Norway!
Jeanine and Chuck said:
There’s a Nobel Prize…
Wayne Tyson said:
What size would a “comet” of a common water content have to be to be heated to a temperature less than the maximum of a known encysted thermophilic bacterium?
How would this bear on the dirty snowball theory?
What conditions, exactly, would be necessary for an arsenic-eating bacterium (GFAJ-1 of the Halomonadaceae) be necessary to survive such an entry?
What are the physiological limits and requirements of GFAJ-1 of the Halomonadaceae?
Ashwin said:
Next Nobel prize winner is here :).
Mike Locke said:
While discussing Mono Lake, perhaps we could all be aware that this is a native American word (not Greek) meaning Salt Fly and is pronounced with 2 long Os.
Felisa (also Opra) are both on camera mispronouncing Mono Lake.
Eduardo said:
Congratulations Felisa, I watched carefully the announcement yesterday on NASA Tv and it was amazing! Im very proud of people like you.
Greetings from Mexico!
Christian Schmidt said:
This is certainly an extremely interesting discovery and I like to congratulate Felisa Wolfe-Simon and her team!
However, from the results published in the Sciencexpress article I would conclude that GFAJ-1: – Still requires phosphate for its growth – Can partially substitute arsenate for phosphate – Shows reduced growth under +As/-P conditions.
It seems to me that this clever little bug has learned to survive under adverse conditions, but still has to pay the price of the instability of the arsenate-analogues of phosphorylated compounds like 1,3-Bisphosphoglycerate and many others.
It should be very interesting to learn how this is achieved: By brute force (e.g. increase the turnover until you get as much energy as you need to survive in combination with a DNA repair system as efficient as in Deniococcus) or by a more subtle approach that stabilizes vital compounds (e.g. by binding to special proteins or by modifications of the cytoplasm like the synthesis of compatible solutes as in halophilic organisms).
It will also be very interesting to find out if there are other organisms that can do the same as GFAJ-1. The current phylogenetic analysis suggests to me that the unusual skills of GFAJ-1 are the results of a “late” adaptation rather than a relic of archaic properties (compare references to the panspermia hypothesis in another comment). The discovery of other organisms (in particular members of the Archaea) with similar properties could change this interpretation (but still will not make me a believer of the panspermia hypothesis).
Steve said:
Even as a child I used to say “Why does life on other planets have to be the same as us? Maybe they could breathe methane or something?”. Why has it taken scientists so long to come to the same conclusion? (Minus the methane, that was just an example). I never understood why they always ruled out life on planets that had no oxygen. Just because we need it doesn’t mean aliens do!
John Taylor said:
This is very interesting indeed and raises other questions. What would happen to humans if these bacteria became a part of the extensive microbiological flora on and in our bodies?
Another point, could there be other interesting microorganisms in, for example, the Aral sea and other similar areas?
Peter Smith said:
One thing is not quite clear from a close reading of the text.
Are the microbes growing naturally in the Mono Lake using arsenic instead of phosphorus in their DNA or was it merely that in the laboratory, being initially fed on high arsenic and low phosphorus, when the latter was withdraw altogether they were able to continue by replacing phosphorus with arsenic?
Although even the latter is significant, there is a big difference between the two scenarios. The headline suggests a naturally occurring phenomena, but the detailed text suggests (human) intelligent design.
Anonymous said:
This “discovery” sounds like NASA is taking the first baby step into revealing to us that alien life exists, has visited this planet, and may be about to visit us again, perhaps in 2012. Sounds nutty … like ancient peoples building pyramids by themselves. Stand by for more baby steps.
jc said:
That’s an amazing discovery; congratulation to the entire team!
But let me add my question here: what does it exactly imply to our life theory? Don’t we already know life’s forms staying deep into oceans, based on chmiosynthesis instead of photosynthesis, using sulfur instead of oxygen to grow? Is it not “just a new” breach in life paradigms?
adam said:
Is this second genesis?
Kai Ren said:
As a 10th grade biology teacher, I’m just blown away with this discovery. The timing couln’t be better, as this comes at the very point where I’m teaching my kids about DNA replication. Can’t wait to tell them about it. Congrats to Felisa and her colleagues from Shanghai, China!
Binbin said:
What an amazing discovery.
Even though I am not a biology expert, i am still amazed by this discovery.
Alan Kellogg said:
One important thing to remember is that arsenic is similar chemically to phosphorus, but it is not exactly the same. Which means that if GFAJ-1 uses arsenic in place of phosphorus in all particulars, technically speaking the bacterium does not have DNA, but an analogous chemical. If this be the case, then Dr. Wolfe-Simon and colleagues have discovered a new domain of life. An arsenic using domain alongside our phosphorus using domain.
With two domains of life now known, that means it is now far more likely that other domains exist in the universe. I’d say that further study of GFAJ-1 is warranted.
jean-claude Perez said:
we could prove theoretically why ARSENIC and PHOSPHORUS provide a good atomic mass level od DNA skeleton as described in the book CODEX BIOGENESIS by J.C. perez
see here:
golden
Sam said:
First of all, congratulations to Felisa and her team :)
Being a science student in my school days, I can certainly vouch for the importance of this discovery by Felisa. Although it has been over 10 years that I last touched my chemistry book (I work in the media sector for international treaties now), I can certainly feel this will motivate the younger generation to think beyond the obvious and now that we have a seventh member in the family (Arsenic), this is one of the biggest proof that alternative life is certainly possible.
Love and Regards from London.
Gwen E. Shafer said:
Very impressive finding. Is it “just” the DNA that includes arsenic rather than phosphorous? Does the bacterial equivalent of the Krebs cycle utilize it as adenosine triarsenate? Or is there another mechanism for incorporating As versus P into DNA and elsewhere?
Proteins processing arsenic rather than phosphorus presumably need a slightly larger, or more flexible, pocket to accommodate the somewhat larger As ion. Since these microbes seem able to grow in the lab on either As or P, it implies flexibility.
Surely some phosphorous must be available in Mono Lake, if only from bird droppings.
Alex said:
CONGRATULATIONS to all researchers!!!
This is amazing unbelievable historic discovery!!!
molecular biology student
David Komanek said:
Certainly too far from the real science, but I like to play with the thoughts about terestrial life being prepared itself to go to the Space before our planet is unhabitable:-)
Jason Pickering said:
Does anyone know where I can get the publication to read about the new microbe?
Alexandre Wajnberg -Skynet said:
Did she found in the lake microorganisms already incorporating arsenic, or did she select, in her lab, some bacteria which happened to mute (by chance) and which, just after, found a good growing support in her phosphorus-starved arsenic-rich growth medium?
Peter Naus said:
So I guess ATP is now adenosine tri-arsenate, right? ATA?
So what will they be calling RNA/DNA built using arsenic? Or are the acid groups the only thing that defines the ribonucleic bit?
Whatever the answers are, I think Felisa’s work is an exciting extension of our knowledge. Well done to her and her team!
Gwen Davies said:
I’m unclear- was the bacteria discovered in its natural environment already substituting arsenic for phosphorous, or were they cultured to do so in a laboratory environment?
john clean said:
Where the conditions of life are right, life will exist. We just have to get away from this egocentric view of life on earth as some sort of ‘divine miracle’. In our known universe, what is becoming apparent is not the miracle of life, but the inevitability of life.
carsten said:
- Any response to the criticism?
www.nature.com/news/…
Antonio Kobashikawa Carrasco said:
Congratulations, and thank you.
Hugo Wagner said:
Great discovery! Congratulations! Keep up the good work and may be one day we will be able to widen the mere concept of “LIFE”.
Athos Robinson said:
First. congratulations to Dr. Felisa Wolfe-Simon, for her commitment for science, till extremes to risk skin damage introducing legs through extremely alcaline waters. Discoveries come regularly, but to give a life to science is the value.
Second. I think the next step is to study the cristalography of As-DNA, as Drs. Watson and Crick did it around 1951. This approach can bring new data, about atom distances and the locus for fit nucleotids. I think the As-ADN must have a little wider stair because the bigger arsenic atom. Could be possible to fit a little different nucleotids?
Third. Phosphorus is a much more important element for biochemistry. For example, glucose needs PO4 to activate, in the form of glucose-6-phosphate, to enter the cell, with the help of insulin.
To conclude, I suspect the As-DNA case, is a weird metabolic way.
Not a possible style of life.
Athos Robinson
John said:
While I am impressed and delighted in the discovery, I cannot get over one simple thing. We caused the environment that they found themselves in. It was not a natural habitat, it’s a man made one. They adapted to that environment, like life on earth does. In effect, we didn’t find new life, we found life that alter’s the paradigm of what we think is needed to live, based upon our own biology. A bit different of a situation.
Kenneth Lifshitz said:
I was excited to hear this. I have been working on a novel
‘monoville’ for about four years now which focuses in part on the lake (starting back in the 1850s thru the NASA projects-Viking, Rovers, TROV etc). Something new to incorporate in the DNA of the novel.
Gwen Davies said:
@ John,
Again, did they “cause the environment?” Alexandre Wajnberg-Skynet above and I basically had the same question. (“Was the bacteria discovered in its natural environment already substituting arsenic for phosphorous, or were they cultured to do so in a laboratory environment?”)
Did you read somewhere that they did (that we overlooked?) Coverage in the Washington Post and New York Times suggested different answers to this question.
An official comment on this would be nice. (Some of us are college students and can’t pay for the entire report.)