Mono Lake in California, with the bacteria (inset) that lives there. Credit: Science

NASA Finds a “Weird” Kind of Life on Earth

2 Dec , 2010

by

No, NASA has not found life on another planet, but has found life here on Earth that is almost “alien” to our narrow, phosphate-based view of life. Scientists have discovered — or “trained,” actually — a type of bacteria that can live and grow almost entirely on a poison, arsenic, and incorporates it into its DNA. This “weird” form of life, which can use something other than phosphorus — what we think of as a basic building block of life — is quite different from what we think of as life on Earth. It doesn’t directly provide proof of a “shadow biosphere,” a second form of life that lives side-by-side with other life on our planet, but does suggest that the requirements for life’s beginnings and foundations may be more flexible than we thought. This means life elsewhere in the solar system and beyond could arise in a multitude of conditions.

“Our findings are a reminder that life-as-we-know-it could be much more flexible than we generally assume or can imagine,” said Felise Wolfe-Simon, lead author of a new paper in Science. “If something here on Earth can do something so unexpected, what else can life do that we haven’t seen yet?”

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The salt-loving bacteria, strain GFAJ-1 of the Halomonadaceae family of Gammaproteobacteria,came from the toxic and briny Mono Lake, near Yosemite Park in California. The lake has no outlet, so over millennia has become one of the highest natural concentrations of arsenic on Earth.

Although the bacteria did not subsist entirely on arsenic in the lake, the researchers took the bacteria in the lab grew it in Petri dishes in which phosphate salt was gradually replaced by arsenic, until the bacteria could grow without needing phosphate, an essential building block for various macromolecules present in all cells, including nucleic acids, lipids and proteins.

Using radio-tracers, the team closely followed the path of arsenic in the bacteria; from the chemical’s uptake to its incorporation into various cellular components. Arsenic had completely replaced phosphate in the molecules of the bacteria, right down its DNA.

“Life as we know it requires particular chemical elements and excludes others,” said Ariel Anbar, a biogeochemist and astrobiologist from Arizona State University. “But are those the only options? How different could life be? One of the guiding principles in the search for life on other planets, and of our astrobiology program, is that we should ‘follow the elements. Felisa’s study teaches us that we ought to think harder about which elements to follow.”

Felisa Wolfe-Simon, right, a NASA astrobiology research fellow in residence at the USGS, and Ronald Oremland, an expert in arsenic microbiology at the USGS, examine sediment in August 2009 from Mono Lake in eastern California. Credit: Henry Bortman

Wolfe-Simon added, “We took what we do know about the ‘constants’ in biology, specifically that life requires the six elements CHNOPS (carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur) in three components, namely DNA, proteins and fats, and used that as a basis to ask experimentally testable hypotheses even here on Earth.”

The idea that arsenic might be a substitute for phosphorus in life on Earth, was proposed by Wolfe-Simon and developed into a collaboration with Anbar and theoretical physicist and cosmologist Paul Davies. Their hypothesis was published in January 2009, in a paper titled “Did nature also choose arsenic?” in the International Journal of Astrobiology.

“We not only hypothesized that biochemical systems analogous to those known today could utilize arsenate in the equivalent biological role as phosphate,” said Wolfe-Simon “but also that such organisms could have evolved on the ancient Earth and might persist in unusual environments today.”

This new research is the first time that shows a microorganism is able to use a toxic chemical to sustain growth and life.

Sources: Science, paper



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K-PAX
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K-PAX
December 2, 2010 10:45 AM

“Our findings are a reminder that life-as-we-know-it could be much more flexible than we generally assume or can imagine,” Felise Wolfe-Simon

healeyb
Member
December 2, 2010 11:05 AM

This is such amazing news! Can we please start funding NASA more, please?

tims_universe
Member
December 2, 2010 11:14 AM

Watching this now on NASA TV; very exciting research! If only entertainment spending could be forwarded to this kind of research focus, imagine where our species could be!

GekkoNZ
Member
December 2, 2010 11:23 AM

“If only entertainment spending could be forwarded to this kind of research focus, imagine where our species could be!”

We would be knowledgeable but bored smile

tims_universe
Member
December 2, 2010 11:30 AM

@GEKKONZ Really? Ya true, (not to generalize…) but to generalize, most people are pretty dumb… they actually do have the mental capacity to learn, but hey… that requires work!

Nafin
Member
Nafin
December 2, 2010 11:56 AM
Mono lake is gorgeous, it is the second saltiest body of water on the planet and has been shrinking due to the LA aqueduct (which siphons water from its feeder streams) for decades which threatens the chemical process that occurs when the fresh water feeding the lake meets with the brine of the lake resulting in the interesting salt formations you see in the picture that do not exist anywhere else, it also results in a steady climb of the salt content of the water body and will eventually kill the brine shrimp and possibly the strange bacteria that live in it. This is one extreme environment we’d better research before it evaporates, A warning, don’t go swimming… Read more »
Jon Hanford
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Jon Hanford
December 2, 2010 12:07 PM

It really is fun to see the enthusiasm these researchers display in describing their findings at this press conference, which has just ended (their phosphorous guy sounded positively breathless). And they actually fielded some really tough, insightful questions (not too many “where’s ET?” queries). And certainly, a reference to Star Trek’s “Devil in the Dark” episode (w-the Horta) made my day. smile

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
December 2, 2010 12:13 PM
Surely it ain’t alien if it has DNA in it. (I pray not, otherwise we will be having those panspermia nutters on our backs forevermore! As for poor Nafin, I’d be worried about going to sleep at night after swimming in Mono Lake!.Who knows, you might wake up one morning at be transmogrified into on of these critters. Q. Was Mono Lake actually named after the dreaded mononucleosis, I wonder? The inset in the image sure looks like a large phagocytic white blood cell with a simple oval nucleus and clear, grayish cytoplasm. I still think Sarah Palin is likely the best prime candidate for alien life! (I mean, she says she can see Russia from her backyard… Read more »
CrazyEddieBlogger
Member
December 2, 2010 12:45 PM
Hey Crumb – easy with the nut gun… While there’s obviously no evidence for Panspermia, there was also no evidence for extrasolar planets before we had the capability to detect them. Sometimes, lack of evidence is not evidence of a lack. The idea is not discountable. It is not likely that high level functioning organisms can cross interstellar or interplanetary space, and while it is clear that simple molecules can, their transfer is not needed since they can form spontaneously on any planet. BUT – can a self-replicating precursor, or fragments of an organism, which are unlikely to form spontaneously on a planet be more likely to form once (either in space or on a different planet) and… Read more »
Torbjorn Larsson OM
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Torbjorn Larsson OM
December 2, 2010 1:21 PM
It will be interesting to poke behind the article paywall. (Nuts, I should have realized Science or Nature had this _before_ going home.) Cells usually sequester elements they find poisonous, either they use them (say, iron) or not (say, mercury). They say they found arsenic associated with DNA by markers, but if that is that all they have on DNA specifically it is thin gruel; arsenic and DNA could perhaps simply associate. (Say, wrapping DNA around protein sequestered arsenic clumps.) This new research is the first time that shows a microorganism is able to use a toxic chemical to sustain growth and life. Perhaps it was meant to be “_the_ toxic chemical”, because bacterias using perchlorates as food… Read more »
Meate
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Meate
December 2, 2010 1:49 PM

@Nafin

I’m not sure where Mono Lake lies in the list of saltiest lakes, but it’s not second. Lake Asal (~35% [salt content]), the Dead Sea (~34%), the Great Salt Lake (~25%) and a few lakes in the Antarctica (~40%) have much higher salt concentrations than Mono Lake (~10%).

Question
Member
Question
December 2, 2010 3:04 PM

Hmmmm…. I always kinda figured Crumb would have liked having nuts on his back.

Bariman43
Member
Bariman43
December 2, 2010 8:59 PM

I find it more awkward that he used the word “nutters” right after the word panspermia >.<

Anyway, this monumental breakthrough is mentioned almost everywhere I go! If life really is this flexible with the elements that make it up, then life just might be more common that we originally thought!

tdaonp
Member
tdaonp
December 2, 2010 9:15 PM

The definition of life has changed. Instead of the six building blocks all life seemed to be build with, it now turns out life can improvise a little. As many a science fiction writer predicted.

http://thesecondopiniontribune.blogspot.com/2010/12/and-again-science-fiction-writers-led.html

Tony Ryals
Member
Tony Ryals
December 2, 2010 9:51 PM
Pretty amazing however still doesn’t hurt the concept of organic-inorganic coevolution.It almost strengthens it…. Organic-Inorganic Coevolution … by Tony Ryals Before life made a cell it must have occurred, Carbon and minerals wrote their first word, It was the basis of the biospheric revolution, Organic-inorganic co-evolution, From the simplest life-form viral, To the most complex evolutionary spiral, Dances within a watery solution, Using the elements of organic-inorganic co-evolution Even the genetic strand has the phosphorous mineral in its carbon configuration Phosphorous holds not only the key to energy transformation, And life’s respiration But is also essential to store life’s genetic information, And eventually human intellectualization, And what would be chlorophyll, Without magnesium its carbon bonds to fill ?,… Read more »
astronary
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astronary
December 2, 2010 11:21 PM

Bravo! : )

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
December 3, 2010 12:42 AM
I said; “Surely it ain’t alien if it has DNA in it. (I pray not, otherwise we will be having those panspermia nutters on our backs forevermore!”) I made such an assessment, mostly because some panspermia proponents have made comments here at UT in the past that WERE really made by so-called nutters! (NOTE: Actually, not all panspermia proponents are nutters) I’d think that if an organism has DNA, it is probably from earth and not necessarily from elsewhere! If it were alien it is far more likely to have a completely different structural and chemical organisation; and even a different energy source (I.e. radioactivity.) (An example is in the Michael Crichton sci-fi film “The Andromeda Strain” (1969).)… Read more »
GBendt
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GBendt
December 3, 2010 12:56 AM

If you think you know all the essential demands life needs to flourish, it may teach you the lesson that it can replace a missing essential demand if it needs to do so. It is somehow prepared to cope with the unforeseeable. Are we?

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
December 3, 2010 1:31 AM

@ Gbendt,

I agree, and philosophically, this is quite true!
However, it does not necessarily mean it is alien but life instead is far more diverse. … and that IS a very important distinction.

Ask yourself, how many different species have ever lived on our planet since the first signs of life?

Question
Member
Question
December 3, 2010 2:40 AM

Dear mr.Crumb

You brought it upon yourself by constantly picking fights with people who disagree with you. Don’t be surprised when someone finally calls you on it.

If you go back over all of my responses to your “every word”, you will see that I only respond when you are trolling. That includes this article. When you are actually sticking to the topic and behaving, I ignore you. If you don’t want me writing counter-troll to your troll, then simply stop carrying on with it and you’ll never hear from me again. Trolling is not “critical thinking”.

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