Bacteria not made of arsenic after all

Claims of ‘new biology’ and ET life fall flat


Published: 12 July 2012 (GMT+10)
NASA Mono Lake, California—where the supposed ‘arsenic-eating bacteria’ were found.
Mono Lake, California—where the supposed ‘arsenic-eating bacteria’ were found.

At the end of 2010, we commented on claims that NASA scientists had found evidence of arsenic-eating bacteria that supposedly supported the idea of ET life (see NASA’s ET suffered arsenic poisoning!) and followed the controversy as it unfolded (see the two postscripts appended to the original article). The whole controversy started with a cryptic press release by NASA that said this:

“NASA will hold a news conference at 2 p.m. EST on Thursday, Dec. 2, to discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life [emphasis added].”

The mere mention of ‘ET’ set the media and the blogosphere ablaze with speculation. It had some more radical commentators prognosticating that NASA was going to produce a live ET, or some other such nonsense. The find was much more prosaic than this, but was still very significant for our understanding of biology on Earth if true. Research was published in Science that announced evidence of the discovery of the first life we knew of that incorporated Arsenic (As) into its biomolecules, including its DNA.1

Arsenic is a close chemical analogue of phosphorus (P), and this research was presented as evidence that an organism was able to replace P with As in its biochemical structure. Phosphorus is essential for numerous biomolecules, including essential ones like DNA, RNA, and ATP (adenosine triphosphate), and the substitution of such an essential and ubiquitous nutrient was completely unheard of. Arsenic is certainly not identical to phosphorus,2 and is better known as a poison.

However, upon hearing the news the blogosphere was again set abuzz. However, this time it was not by radical speculations about ET, but by numerous highly qualified scientists slamming the work as bad science. The researchers defended their work, and basically said: “The blogosphere is not the place for scientific debate—let our detractors refute us in the scientific literature.” While this was rather disingenuous given the way the news was revealed, scientists took up the challenge. Two research papers from independent teams seeking to confirm the original claims have just recently been published—again by Science.3,4 It looks like the skepticism this claim was met with was justified—the results are not pretty for the idea that these bacteria (called GFAJ-1) incorporate As into their biomolecules.

What was wrong with the original claim?

The research teams identified numerous problems with Wolfe-Simon et al.’s1 claims. One problem identified by both Reaves et al.3 and Erb et al.4 was that numerous tests failed to find any detectable As in the DNA of GFAJ-1 regardless of As or P concentrations. Both studies found that no As was found in the structure of the DNA of GFAJ-1 when analysed by mass spectrometry,5 and the DNA didn’t behave in water outside of the cell as would be expected if it contained As in its structure.

Moreover, As was not found in any molecules linked to metabolism in GFAJ-1 regardless of As concentration, but P was always found. This was confirmed by the fact that when the P levels were too low for growth, even high As concentrations didn’t enable growth, which directly contradicts Wolfe-Simon et al.’s claims. Some potential As ‘metabolites’ were found in low concentrations, but Erb et al. concluded that they were due to abiotic reactions and only a negligible amount might have been due to biotic reactions—certainly not enough to significantly impact either core or secondary metabolism in GFAJ-1.

Perhaps the most overtly damning result of both studies for the original research is that they were both able to grow GFAJ-1 on concentrations of P lower than the “–P” trials of Wolfe-Simon et al. even at high As concentrations. This not only suggests that As has nothing to do with the growth of GFAJ-1, but it also suggests that the methodology of Wolfe-Simon et al. was sloppy. If the so-called “–P” trials had enough residual P in them to facilitate growth of GFAJ-1 regardless of the As concentration, then there is no evidence that As actually contributes to the growth of GFAJ-1, and Wolfe-Simon et al. failed to purify their trials well enough to demonstrate what they purported to demonstrate.

It is interesting that this was exactly what one of the original scientific skeptics of the claims with relevant expertise to comment, Dr Alex Bradley, predicted would happen. Dr Bradley’s whole blog comment is eerily predictive of most of what both research teams did, and the results they got—and he was not involved with either research paper. For those interested in the original research, I recommend reading Dr Bradley’s comments alongside the current research—it’s an instructive look at science at its predictive best.

With the original claims basically invalidated, the onus is now on the proponents of the ‘As-eating bacteria’ claims to put forward some proper evidence.

Proponents of As-eating bacteria respond?

Not surprisingly, the proponents of the original claims have not been silent in response. Lead researcher of the original claims Felisa Wolfe-Simon intimated that she and others are seeking to publish new data in support of their original interpretation in the future.6 It will be interesting to see if they can successfully address the criticisms levelled at the original claims. But she also made this rather bizarre comment:

“The original GFAJ-1 paper emphasized tolerance to arsenic, but suggested the cells required phosphorus, as seen in these two new papers. However, our data implied that a very small amount of arsenate may be incorporated into cells and biomolecules helping cells to survive in environments of high arsenate and very low phosphate. Such low amounts of arsenic incorporation may be challenging to find and unstable once cells are opened [emphasis added].”7

There are a number of excuses offered in this statement, despite the fact that there were numerous ways in which these present studies were much more careful in their methods than her own. However, one aspect of this statement left me completely bewildered. Her article “emphasized” As tolerance and only “suggested” the replacement of P with As? I have to say that if this is true, then everything I’ve heard or read on this controversy—including her original research article—has profoundly misrepresented her intended point. The very title of her original paper explicitly contradicts what she says: “A bacterium that can grow by using arsenic instead of phosphorus”.1 The emphasis is clearly on As replacing P as an essential part of biomolecular structure, not As tolerance. She has blatantly contradicted herself and everyone else who has ever written on this controversy.

The title of one science news article deserves special comment. The article is titled “Arsenic-munching bacteria doubted, but still alien-like”.7 It is the only article I have come across on this latest research to mention ET life. The recent research completely crushed the original claims, and the text of the article doesn’t mention anything about ETs. The closest the article comes is at the end, where the writer and one of the researchers say that GFAJ-1 is a “remarkable” organism given its extreme As tolerance. And this is true, but what’s that got to do with ET life? Life is an amazing phenomenon, but that doesn’t mean ETs exist! It just goes to show that some still want to use this whole controversy to promote the ET agenda. The fact is, however, even I was aware of numerous As-tolerant microbes and plants nearly 10 years ago as an undergraduate environmental science student—and they are all most definitely earthly organisms. There’s nothing new or ET about As-tolerant microbes, which now appears to include GFAJ-1. They are just another type of extremophile (see Life at the extremes).

A publicity stunt gone bad

This was a publicity stunt from the beginning promoting the ET/evolutionary worldview, and it backfired almost immediately. Microbiologist Rosemary Redfield of the University of British Columbia, and co-author of ref. 3, was among the first outspoken critics of the initial study, with a scathing blog comment:

“I don’t know whether the authors are just bad scientists or whether they’re unscrupulously pushing NASA’s ‘There’s life in outer space!’ agenda.”8

And now we’ve got two independent studies presenting strong support that it should have backfired from the beginning. Even if some organisms, even GFAJ-1, can incorporate As as a replacement for P into their biomolecules, there is at present no evidence supporting the claim—and such a claim wouldn’t even be antithetical to biblical creation. But all the evidence put forward to date has been invalidated. So now it’s time for the proponents to provide new evidence—if they can. These two research papers are examples of how science should work—it’s just a shame that good science almost invariably only gets the spotlight whenever bad science gets the spotlight first.


  1. Wolfe-Simon, F. et al., A bacterium that can grow by using arsenic instead of phosphorus, Science 332:1163–1166, 2 December 2010. Return to text.
  2. Arsenic is larger, and its V oxidation state—the state of phosphorus in most biochemicals—is less stable, easily reduced to III. Return to text.
  3. Reaves, M.L. et al., Absence of detectable arsenate in DNA from arsenate-grown GFAJ-1 cells, Science (DOI:10.1126/science.1219861), Published online 8 July 2012. Return to text.
  4. Erb, T.J. et al., GFAJ-1 is an arsenate-resistant, phosphate-dependent organism, Science (DOI: 10.1126/science.1218455), Published Online 8 July 2012. Return to text.
  5. See for a helpful definition of a mass spectrometer. Return to text.
  6. Kaufman, M., Journal retreats from controversial arsenic paper, Washington Post,, as at 10 July 2012. She made this statement with Dr John Tainer. Return to text.
  7. Emspak, J., Arsenic-munching bacteria doubted, but still alien-like, LiveScience,, 9 July 2012. Return to text.
  8. Redfield, R., cited in: Scientists disprove arsenic life form claim, ABC News,, 9 July 2012. Return to text.

Helpful Resources

By Design
by Dr Jonathan Sarfati
US $15.00
Alien Intrusion
by Gary Bates
US $12.00

Reader’s comments

Haydn M.
Its mind boggling how hungry the the world is to swallow the lies of any anti-christian world view or false science and how disinterested they are in the truth. Thanks CMI.
Danie P.
What a shocker! My parents, specifically my Mom now age 62, have tremendous respect for anyone with a high qualification. She never doubted any claim made by "clever people with doctorates", cause they obviously know what they are talking about, they studied extensively and she is only a primary school teacher. It took me a couple of years to convince them that they can rather trust the Word of God than the word of man. This is why I hate publicity stunts like these, it deliberately misinforms the public and there are many people like my parents...
Rodney F.
When bad science gets out, it usually reaches beyond the boundary of good science that refutes it. Therefore bad science has a lot (and long lasting) collateral damage that we can never rectify. Bad scientists know this, so they will do this time and time again – now for 150 years. Present bad science often and long enough, the false collateral or surplus data is unreachable and becomes ‘truth.’ “We all know that the Neanderthal man is a proven fact.” (tongue in cheek).
Andrew S.
While it seems there is an agenda to prove the existence of life elsewhere - or at least try to find evidence of it - the NASA crowd jumped the gun with their early statements. The fact that their claims have been brought into question is simply science continually questioning, checking and re-checking claims that are made. It is a positive outcome that, while not proving "ET", proves the efficacy of scientific rigour.
Shaun Doyle
We need to be careful with our praises here. This was not a simple victory for the notion of “science continually questioning, checking and re-checking claims that are made”. This one was an easy target that was goading the scientists to shoot it down. Scientists may not have been so quick to test these claims if it wasn’t for the way NASA publicized the original research. Scientists would’ve questioned it, sure—it was a bold claim regardless of how it was promoted. But as scientifically important as it was, few people outside the scientific world would’ve known or cared about it if the ‘ET’ label hadn’t been attached to the claim. So we can thank NASA’s penchant for shameless promotion of the ET agenda more than anything else for the rapid and very public downfall of this bad science. But the evolutionary framework hasn’t been abandoned—see e.g. this quote from the PhysOrg article: “NASA has conducted numerous probes at eastern California’s Mono Lake, an unusually salty body of water with high arsenic and mineral levels, as it is likely to reflect conditions under which early life evolved on Earth, or perhaps Mars.” Such a statement is baseless speculation, and yet we won’t find secular scientists getting worked up about that. The notion of science as “continually questioning, checking and re-checking claims that are made” doesn’t reflect the regular realities of what actually goes on. Science is a human discipline, and for all its great achievements it’s still subject to all the same foibles, blind prejudices, and sins that any human endeavour is. And evolution only serves to make it worse—see A look at some myths about scientists.
Grant D.
I completely agree with John. Good article
Kyle L.
As a Christian that has studied evolution in college, I can say that CMI is absolutely right in every sense. The athiest, using evolutionary theory as his tool, will always be grasping for straws. I know that sounds rude, but I have spoken to them myself, and there are too many things that point to a Creator. I hope the CMI becomes known worldwide and by everyone. Keep up the good work.
Kyle L.
As a Christian that has studied evolution in college, I can say that CMI is absolutely right in every sense. The atheist, using evolutionary theory as his tool, will always be grasping for straws. I know that sounds rude, but I have spoken to them myself, and there are too many things that point to a Creator. I hope the CMI becomes known worldwide and by everyone. Keep up the good work.
John T.
When the original ‘alien life form’ claim was made, the mainstream media hyped it dramatically, including, if I recall correctly, front page coverage. Now that it turns out to be bogus, I have not seen the mainstream media report this, and the propaganda remains in the minds of the general public. This is how evolution claims normally operate. CMI is at its very best here exposing such nonsense.
Al M.
Thank you for the wonderfully written article.
This really makes you think about how blatantly obsessed mainstream culture is with ETs, and how incredibly foolish the assumptions behind it are. First and foremost, life has been demonstrated innumerable times to only come from life, which alone dashes any ET pipe dreams. To believe life arose on other planets is to believe in breaking at least 2 proven scientific laws (biogenesis and entropy) that are so damning to evolutionary theory that I'm surprised people still think abiogenesis is plausible and a creature could remain EXACTLY THE SAME over "hundreds of millions of years."
With that in mind, the speculation of life using Arsenic (which is known as poison to life by many) instead of Phosphorus shows another clear lack of understanding in biochemistry. Every day science pulls us closer to the truth, creationism.

Thank you for your wonderful ministry, it brings a ray of hope to a weary world. Keep up the good work!
Errol B.
Thanks to Calvin Smith in ‘Genesis Unleashed’ for alerting me to a science forum titled ‘What is Life?’ held at Arizona State University Feb 2011 and included 8 scientists including Richard Dawkins, Paul Davies, NASA’s Chris McKay and genome guru Craig Venter. There were some very interesting admissions, which should have been made a great deal more of, but mostly ignored. At the 5:40 mark, NASA’s Chris McKay admitted the fossil record shows that the earliest life forms seem to have just appeared fully formed to a high level of complexity, suggesting these life forms likely hitched a ride on a meteor. McKay was trying to justify NASA’s agenda of searching for life in space. With all the dollars spent over the decades on research of the origin of life, it looks like the genetic code wrote itself on another planet but then came the bomb shell at the 9:00 minute mark to 11:45 mark when Craig Venter, (an evolutionist who made world news a few years ago by custom designing chromosomes and is involved in 'hands on' experimental science in the lab, more than any other scientist on the panel) told Davies he was wrong, there are multiple genetic codes, as tabled on the website for the ‘National Centre for Biotechnology Information’ (NCBI), 17 or 18 so far. Venter said, “Well I think the [Darwinian] tree of life is an artefact of, arr, some early scientific studies that aren’t really holding up”. So now we’ve gone from historical or forensic type of science (fossil record) revealing the genetic code didn’t write itself on earth, to laboratory research revealing there are at least 17 instances of genetic codes writing themself, which is in conflict with the fossil record, and common sense for that matter. The final exchange between Venter and Dawkins said it all, with Dawkins stammering for words; “I, I, I’m in, intrigued in Craig saying that he, that, that the [Darwinian] tree of life is a fiction, I’d, I’d, mean the, the DNA code of all creatures that have ever been looked at is all but identical and um, surely that means that they’re all related..............doesn’t it?” To which Venter just smiles. Why did Dawkins, McKay etc decide to not believe Venter? They couldn’t afford to, as Dawkins was at least brave enough to put his neck out in ‘The Greatest Show on Earth’ (2009, p. 409-10), admitting the common ancestry theory would be dealt a fatal blow if there were evidence the genetic code itself had mutated. This is huge. It’s one thing to ignore a biblical creationist during origins discussions, they can accuse us of bias and being brainwashed, but how do they justify ignoring one of their own, who is a leader in that particular field? Leading evolutionists choose what evidence to believe, not base on science or facts, but on ideology.
andrei T.
Very good article; thanks for keeping us up to date on this. Our tax funded media outlets clearly have more important things to worry about ;).

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