Scientists propose new hypothesis on the origin of life

Sep 04, 2009 by Anuradha K. Herath
The new hypothesis suggests that life on Earth originated at photosynthetically-active porous structures made of zinc sulfide similar to deep-sea hydrothermal vents. Credit: The Institute for Exploration, the University of Rhode Island (URI) Graduate School of Oceanography (GSO), and the URI Institute for Archaeological Oceanography.

The Miller-Urey experiment, conducted by chemists Stanley Miller and Harold Urey in 1953, is the classic experiment on the origin of life. It established that the early Earth atmosphere, as they pictured it, was capable of producing amino acids, the building blocks of life, from inorganic substances.

Now, more than 55 years later, two scientists are proposing a hypothesis that could add a new dimension to the debate on how life on Earth developed.

Armen Mulkidjanian of the University of Osnabrueck, Germany and Michael Galperin of the U.S. National Institutes of Health present their hypothesis and evidence in two papers published and open for review in the web site Biology Direct.

The scientists suggest that life on Earth originated at photosynthetically-active porous structures, similar to deep-sea hydrothermal vents, made of zinc sulfide (more commonly known as ). They argue that under the high pressure of a carbon-dioxide-dominated atmosphere, zinc sulfide structures could form on the surface of the first continents, where they had access to sunlight. Unlike many existing theories that suggest was a hindrance to the development of life, Mulkidjanian and Galperin think it actually helped.

“The problem of the is such that you have to answer a set of different questions to explain how life has originated,” says lead author Mulkidjanian. “We just provide answers to the problem of energetics of the origin of life.”

Altering the Early Atmosphere

According to Mulkidjanian, the debate about whether life could arise from chemical reactions began to change when scientists started to question the atmospheric conditions used by Miller and Urey. In their famous experiment, Miller and Urey replicated the atmosphere with a mixture of methane, hydrogen, ammonia and water vapor. This mixture, along with some “sparks” which simulated lightning, led to the formation of amino acids. With this setup, Miller and Urey assumed that the early Earth had a reducing atmosphere, which meant it had large amounts of hydrogen and almost no oxygen.

Miller-Urey experiment (1953). Image: YassineMrabet, via Wikipedia.

However, many scientists have now abandoned the notion of a reducing early . Instead, they believe Earth had a neutral atmosphere, composed primarily of , with smaller amounts of nitrogen and hydrogen, similar to the modern atmospheres of Mars and Venus. Researchers who have repeated the Miller-Urey experiment under the new atmospheric assumptions, including Miller, have shown that this new mixture does not produce amino acids.

“After it became clear that the origin of the atmosphere was made of carbon dioxide,” says Mulkidjanian, “there was no physically or chemically plausible hypothesis of the origin of life.”

Living organisms can exist only if there is some form of energy flow—solar radiation or chemical reactions, for example.

“If you have an atmosphere of carbon dioxide, you need, in addition, a source of electrons to reduce carbon dioxide if you want to make complex compounds,” Mulkidjanian explains.

From A-biotic to Zinc

Mulkidjanian’s “Zn world” hypothesis presents a different version of the prebiotic Earth atmosphere—one in which zinc sulfide plays a major role in the development of life. In nature, zinc sulfide particles precipitate only at deep-sea hydrothermal vents. Its unique ability to store the energy of light has made it popular in many modern-day devices, from various types of television displays to glow-in-the-dark items (and zinc oxide is used in sunscreen).

Its ability to store light makes zinc sulfide an important factor in the discussion on life’s origin. Mulkidjanian explains that, once illuminated by UV light, zinc sulfide can efficiently reduce carbon dioxide, just as plants do.

To test the hypothesis, Mulkidjanian and Galperin analyzed the metal content of modern cells and found “surprisingly high levels of zinc,” particularly in the complexes of proteins with DNA and RNA molecules.

“We have found that proteins that are considered ‘evolutionarily old’ and particularly those related to handling of RNA specifically contain large amounts of zinc,” Mulkidjanian says.

The scientists say the result is evidence that the first life forms evolved in a zinc-rich environment. But as the authors indicate in their paper, acceptance of a new hypothesis for the origin of life will likely require more work, particularly to further describe the nature of life and the chemical reactions in these zinc-rich communities.

“We cannot explain fully the properties of modern organisms unless we understand how life has originated,” says Mulkidjanian.

For astrobiologists, this new hypothesis presents a considerable shift in the debate on the origin of life.

“If this hypothesis is adopted in the origins of life community, it would represent a real conceptual shift, and so it would be significant,” says NASA astrobiologist Max Bernstein. “Whether it will be adopted or not eventually I cannot say, but I expect that many will want to see experimental evidence of the viability of reactions consistent with the hypothesized scheme under prebiotic conditions.”

Source: Astrobio.net, by Anuradha K. Herath

Explore further: Oxygen levels were only 0.1 percent of today's levels for roughly billion years before rise of animals

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Myria83
4.2 / 5 (5) Sep 04, 2009
I don't think that one hypotesis rules out the other... Why don't we consider multiple mechanisms in action billions of years ago, instead of looking for one single explanation? Maybe life originated in different environments and in different ways, along the course of the Earth's history...
tkjtkj
3 / 5 (6) Sep 04, 2009
.. Why don't we consider multiple mechanisms in action billions of years ago, instead of looking for one single explanation? Maybe life originated in different environments and in different ways, along the course of the Earth's history...


i think its a 'hold-over' from our history of religions.. where its easiest to conjure up some ecclesiastical finger pointing to earth, and an uttering of 'let there be light ..and man ... ' etc ..


GaryB
4.7 / 5 (3) Sep 04, 2009
One thing that makes a lot of sense is their consideration of the need of an energy flow. It's not enough to have a soup and some membranes, the soup needs energy (here, UV light) and a method of converting the energy to useful work in the physics sense. They at least have that.
exapted
4 / 5 (3) Sep 04, 2009
I don't think that one hypotesis rules out the other... Why don't we consider multiple mechanisms in action billions of years ago, instead of looking for one single explanation? Maybe life originated in different environments and in different ways, along the course of the Earth's history...

I think this might explain it, from the article:

“The problem of the origin of life is such that you have to answer a set of different questions to explain how life has originated,” says lead author Mulkidjanian. “We just provide answers to the problem of energetics of the origin of life.”

So they think there are other mechanisms involved.

I don't think they are rejecting the Miller-Urey experiment. But if life originated in a neutral atmosphere, then the Miller-Urey experiment doesn't seem to apply.

I really don't think biologists are looking for a single moment of creation. It's just that there only needs to be one sort of complete set of mechanisms, explaining how the replicators of evolution originated.
E_L_Earnhardt
1.5 / 5 (8) Sep 04, 2009

A "closed mind" can not conceive of anything new!
If they have a TEACHER with a "closed mind" they will not be ENCOURAGED to LOOK for something new!
I say the ELECTRON has the longest history! There is no "life" without it even today!



MongHTanPhD
1 / 5 (4) Sep 04, 2009
RE: The new dynamism of the origin of life on Earth!?

I don't think that one hypothesis rules out the other... Why don't we consider multiple mechanisms in action billions of years ago, instead of looking for one single explanation? Maybe life originated in different environments and in different ways, along the course of the Earth's history...


I think that's exactly the new scientific thinking of life origins on Earth, that I outlined in my seminal book "Gods, Genes, Conscience" (URL links below; and please see Chapter 2: The Universal Elements of Life; and Chapter 3: The Physicochemical Basis of Life) from the Quantum Mechanics of STEM (space, time, energy, matter) point of view; and approached it from the interdisciplinary method and dynamism of STEM (science, technology, engineering, mathematics) analyses!?

Best wishes, Mong 9/4/9usct3:54p; practical science-philosophy critic; author "Decoding Scientism" and "Consciousness & the Subconscious" (works in progress since July 2007), "Gods, Genes, Conscience" (2006: http://www.iunive...95379907 ) and "Gods, Genes, Conscience: Global Dialogues Now" (blogging avidly since 2006: http://www2.blogg...50569778 ).
Ant
1.6 / 5 (7) Sep 04, 2009
None of these hypothasis explains our mental capabilities. OK it may explain why our planet has biological entities but not why we are sentient.
fortinbras
3.5 / 5 (2) Sep 04, 2009
omg Ant, spell correctly and we can take your question seriously. Sentience is a highly complex set of both sensing and information processing systems. There is no single definition of sentience, and attempts at reduction bring flawed conclusions. The question you might be seeking to ask might be more "What are the possible origins of counter-entropic biological systems of ordering leading to both thought and autonomy?" Now that is a real miracle...
Ant
2.3 / 5 (3) Sep 04, 2009
whats omg
Balanor
5 / 5 (1) Sep 04, 2009
Enough with the amino acids and amoeba.
Who is the idiot that created roaches and mosquitoes!!
gideon
3 / 5 (2) Sep 04, 2009
whats omg


Oh My God if you don't know by now you may never figure it out.
MrFred
1 / 5 (7) Sep 05, 2009
I think that one day when we know how this all happened, all of us are either going to laugh or cry at some of the ideas we came up with for the origin of life.
It's too bad evolution is driven by the religion of anti-creationism instead of by science. Science might actually take us somewhere!
Ethelred
3.3 / 5 (7) Sep 05, 2009
It's too bad evolution is driven by the religion of anti-creationism


Go learn something. Evolution is a process, there is no religion involved in understanding it. Creationism is a religious belief that is primarily about denying evolution. Turning the truth around on its head won't make that go away.

Science took us to the Moon. What planet are you living on where you think it has done nothing?

Here is a good site to start learning so you can have a clue as what evolution is instead of using Creationist propaganda.

http://pandasthumb.org/

Ethelred
MongHTanPhD
1 / 5 (5) Sep 05, 2009
RE: The origins of consciousness and sentience!?

None of these hypotheses explains our mental capabilities. OK it may explain why our planet has biological entities but not why we are sentient.
and

omg Ant, spell correctly and we can take your question seriously. Sentience is a highly complex set of both sensing and information processing systems. There is no single definition of sentience, and attempts at reduction bring flawed conclusions. The question you might be seeking to ask might be more "What are the possible origins of counter-entropic biological systems of ordering leading to both thought and autonomy?" Now that is a real miracle...
and

I think that one day when we know how this all happened, all of us are either going to laugh or cry at some of the ideas we came up with for the origin of life.

It's too bad evolution is driven by the religion of anti-creationism instead of by science. Science might actually take us somewhere!


I thought these are more advanced scientific and spiritual queries that are beyond the scope of this panel discussion of the origin of life question; and that you all might be interested in exploring some of my recent, relevant comments here: http://ecodevoevo...09613882 "Do ants think? -- RE: Do or can ants think? -- Hardly!" (TheMermaid'sTaleUSA; September 1); and here: http://www.physor...182.html "Why sleep? Scientist delves into one of science's great mysteries -- RE: How/why we sleep!?" (PhysOrgEU; August 23); and here: http://www.guardi...df1fec75 "When does fandom become religion? -- RE: It all depends on fans' wisdom!?" (GuardianUK; July 21).

Best wishes, Mong 9/5/9usct11:02a; practical science-philosophy critic; author "Decoding Scientism" and "Consciousness & the Subconscious" (works in progress since July 2007), "Gods, Genes, Conscience" (2006: http://www.iunive...95379907 ) and "Gods, Genes, Conscience: Global Dialogues Now" (blogging avidly since 2006: http://www2.blogg...50569778 ).
Ant
5 / 5 (2) Sep 05, 2009
Fortinbras & Gideon

those that should be banned from this forum are those who prefeer to be abusive to others when a simple statement is made or a question is asked quite respectfully of the inteligent who use this site of which there seems to be very few.



Good English is that which is clear and concise that all others can understand it does not include acronyms or abreviations like some demented texter. It also should not include fancy phrases such as counter-entropic when simple wording such as "ordering" is adequate. I will admit spelling is not one of my best skills but I am prepared to bet that far more understood my post than that of Fortinbra, shouldnt that have a capital initially as should omg. please note that I have reported both the post from the above as inapropriate and damaging to this forum.



A Rigby BSc(hons),PGd
Doug_Huffman
2.5 / 5 (2) Sep 05, 2009
It would be convergent evolution for multiple life origins to result in the common life type that we see now - or only one survived making the other 'origins' not of life as we now know it.
PhilJM
not rated yet Sep 06, 2009
Ant:"None of these hypothasis explains our mental capabilities. OK it may explain why our planet has biological entities but not why we are sentient."

Expecting an explination of how life got started to explain how we became sentient is like expecting an explination of the materials for an abicus to explain how a computer functions.

And omg, wtf, otoh, imo, imho, and other short hand comments are common on the web and in comments. Just a part of web life. Get used to it as it isn't likely to change. You can even find lists to make it easier. I know, because I did.
Danie
1 / 5 (2) Sep 07, 2009
whats omg








Oh My God if you don't know by now you may never figure it out.






Oh, so you do believe in Him... Then I wonder why you still have theories as to where intelligent life originated from.
stonehat
not rated yet Sep 07, 2009
Can the author please avoid nonsense like "some form of energy flow".
Ricochet
not rated yet Sep 08, 2009
After sharing a hotel with an alternative education convention (as in unschooled kids running amok and causing damage everywhere), I'm not sure that we're all that sentient...
Ricochet
1 / 5 (1) Sep 08, 2009
After sharing a hotel with an alternative education convention (as in unschooled kids running amok and causing damage everywhere), I'm not sure that we're all that sentient...
mabarker
1.6 / 5 (7) Sep 08, 2009
2 cheers 4 ethyl red! I would partly agree with her post and adjust it saying, *Go learn something. Evolution is an unobserved process, there is much religion involved in understanding how organic life came from inorganic non-life. Evolutionism is a religious belief that is primarily about denying creation science. Turning the truth around on its head won't make that go away.*

MongHTanPhD
1 / 5 (4) Sep 08, 2009
RE: Separating the new dynamism of life-origin on Earth from Dawkinsism!?

I just found out that the young Manchester physicist, Brian Cox, has had been trying to decipher the Quantum Mechanics of life-origin (on Earth and elsewhere in the Universe) all along here: http://www.ted.co...der.html and more here: http://www.ted.co...lhc.html .

Furthermore, I had much difficulty in understanding this one:
2 cheers 4 ethyl red! I would partly agree with her post and adjust it saying, *Go learn something. Evolution is an unobserved process, there is much religion involved in understanding how organic life came from inorganic non-life. Evolutionism is a religious belief that is primarily about denying creation science. Turning the truth around on its head won't make that go away.*
until I properly compared (per verbatim) and edited (with parentheses) the above quote to the original one, like so:
It's too bad evolution is driven by the religion of anti-creationism

Go learn something. Evolution is an [unobserved] process, there is [much] religion involved in understanding [how organic life came from inorganic non-life]. [Evolutionism] is a religious belief that is primarily about denying [evolution]. Turning the truth around on its head won't make that go away. [Ethelred]
and that religion (or evolutionism) is the world-renowned armchair Dawkinsism, that has had been proselytizing from Oxford (UK) since the mid-1970s!? Caveat lector!

Best wishes, Mong 9/8/9usct2:45p; practical science-philosophy critic; author "Decoding Scientism" and "Consciousness & the Subconscious" (works in progress since July 2007), "Gods, Genes, Conscience" (2006: http://www.iunive...95379907 ) and "Gods, Genes, Conscience: Global Dialogues Now" (blogging avidly since 2006: http://www2.blogg...50569778 ).
Ethelred
3.7 / 5 (6) Sep 08, 2009
2 cheers 4 ethyl red!


Amazing! Mabarker acknowledges one of my posts. I think this is a first.

Of course he goes on from there into fantasy land.

*Go learn something. Evolution is an unobserved process, there is much religion involved in understanding how organic life came from inorganic non-life.


Evolution has been observed both in the lab and in fossils. There is no religion needed in understanding evolution. However mabarker keeps pretending that evolution has something to do with biogenesis. Evolution cannot occur occur before life got started. Evolution is real even if a god started life.

Evolutionism is a religious belief that is primarily about denying creation science.


There is no Creation Science. No creationist has ever done a single experiment to support creationism. The only thing they do is to try obfuscate reality.

Go ahead Ma. Show where a Creationist has done an experiment to prove Creationism. Show where they did a test to prove the world is young for instance.

Turning the truth around on its head won't make that go away.*


Absolutely, so why do you do it?

Ethelred
Ethelred
2.3 / 5 (3) Sep 08, 2009
MongHTanPhD said:
Furthermore, I had much difficulty in understanding this one:

That sort of false and misleading bogus or out of context quote is very popular with creationist like Mabarker. He once called someone a convert to Creationism because the man died. Except he failed to mention that the reason was that he died. He first simply claimed that the person had converted. Basically Mabarker is of the Eusebius school of religion where it is OK to lie to support your religious beliefs.
and that religion (or evolutionism) is the world-renowned armchair Dawkinsism, that has had been proselytizing from Oxford (UK) since the mid-1970s!? Caveat lector!


I am not Dawkins. He is an Atheist. I am an Agnostic.

Nor is Dawkins religious. Someone here claimed that he hates religion. I think that is at least as over the top as Dawkins sometimes is. I think he is disturbed by religion and the violence that it has engendered, especially recently. His earlier writings, before the turn of the millennium, were not hostile towards religion. He was however upset, justifiably so, with the way Creationists, such as Ma, keep quoting him out of context. That sort of garbage has been going on for over a century with Darwin.

There is no need for religious beliefs to understand reality. At least not so far. Perhaps in the future but even then it is likely that religious people will claim that since we don't understand everything then a god, most likely THEIR god, must therefor exist.

Ethelred
austux
1 / 5 (2) Sep 12, 2009
I don't think they are rejecting the Miller-Urey Experiment.

Perhaps they should. Miller/Urey failed. It produced interesting chemicals, but _none_ of them useful life-precursors (even-handed molecular polarity was one of several Epic Fails).
austux
1.7 / 5 (6) Sep 12, 2009
There is no need for religious beliefs to understand reality.

Since an Atheist, by definition, holds a key religious belief (A Theism == "there is no Theos"), they are excluded from understanding reality. I think Mr Dawkins would get a bit sad if he were required to acknowledge that.
austux
1 / 5 (4) Sep 12, 2009
Evolutionism is a religious belief that is primarily about denying creation science.


Amendment: Evolutionism is _based_on_ a religious belief (materialism: hyper-determinism), it is not a belief in itself.
MongHTanPhD
1 / 5 (4) Sep 12, 2009
RE: Evolutionism is Dawkinsism vs. Darwinism!?

Evolutionism is a religious belief that is primarily about denying [evolutionary] science.
Amendment: Evolutionism is _based_on_ a religious belief (materialism: hyper-determinism), it is not a belief in itself.
Evolutionism is Dawkinsism: one which Dawkins reduces Darwinism into his pseudo-genetic determinism since the 1970s; and Dawkinsism has since further reduced Darwinism into his current anti-religious rhetoric or neo-atheism without conscience: one which has since become a religious belief in itself by his current worldwide uncritical readership as I analyzed here: http://www.guardi...df1fec75 "When does fandom become religion? -- RE: It all depends on fans' wisdom!?" (GuardianUK; July 21);

[to be continued in next post]
MongHTanPhD
1 / 5 (3) Sep 12, 2009
RE: Evolutionism is Dawkinsism vs. Darwinism!?

[continued from last post]

and here: http://ecodevoevo...28231716 "Genetics in Brazil -- RE: Separating wheat from the chaff -- Neo-Darwinism (or Dawkinsism) vs. Darwinism!?" (TheMermaid'sTaleUSA; September 6).

Best wishes, Mong 9/12/9usct10:34a; practical science-philosophy critic; author "Decoding Scientism" and "Consciousness & the Subconscious" (works in progress since July 2007), "Gods, Genes, Conscience" (2006: http://www.iunive...95379907 ) and "Gods, Genes, Conscience: Global Dialogues Now" (blogging avidly since 2006: http://www2.blogg...50569778 ).
HarshMistress
5 / 5 (3) Sep 12, 2009
For "austux":

Using poetic licence in translation, aren't we?

Prefix "a" is used to indicate absence of something, as in a-theos: godlesness, godless, whith one and only meaning of "non-believer". Atheist allows existence of god(s), but does not believe in it without a firm evidence.

Another problem is that definition of atheism in our dictionaries and encyclopedias is, more often than not, written by a-moral theologians with a sole purpose of distorting the actual meaning of atheism and bringing it to the market of religions as just another one. According to them, atheism is "a belief system which denies existence of god(s)" which is, of course, manipulation at its best.

By the way, "amoral" means "someone who doesn't care whether what they do is considered to be right or wrong" - a total absence of moral scruples. Amoral characters are not *against* morality, they just don't care about it.
gideon
not rated yet Sep 13, 2009
Ant - you can ban me for being ironic i guess.

By the way since it apparently went completely over your head - 'omg' stands for 'oh my god' and I wrote it like that to be funny and let you figure it out yourself but some people don't look for any humor only confrontation on these sites I guess. Frankly I'm rather shocked that you were upset at what I wrote. And if you already knew what omg was before you asked then having someone responding to your question that you put out there to be responded to shouldn't cause you insult since you put it up to be commented on in the first place (whats omg - like that question doesn't sound like a joke in the first place).

Lighten up.
Ethelred
3 / 5 (4) Sep 13, 2009
Since an Atheist, by definition, holds a key religious belief (A Theism == "there is no Theos"), they are excluded from understanding reality.

False. They MAY be unable to understand reality IF there is a god. ONLY IF there is a god and even then it would have to be an active god.
I think Mr Dawkins would get a bit sad if he were required to acknowledge that.

Well it would be a requirement that he lie so he would have right to be sad.

Besides he has admitted that there is tiny possibility of there being a god.

So you are wrong on two points.

Ethelred

Brevity is for soulless twits.

1000 = half as stupid as Youtube.
Which is still indistinguishable from brain dead.

A continuing campaign to convince Pysorg to show that do not want to be Youtube without video.
Ethelred
3 / 5 (4) Sep 13, 2009
Amendment: Evolutionism is _based_on_ a religious belief (materialism: hyper-determinism), it is not a belief in itself.

Evolution is neither a religion nor a religious belief in any way at all. Only a person so steeped in religion that they are unable look at the world at all without filtering it through religious thinking would make such a claim.

It is a theory based on evidence that shows that life evolves.

Perhaps you mean that SCIENCE is based on an IDEA, that is not in any way religious. That idea being that the world is understandable or at least we will never understand it if we assume that we can't.

Then again maybe you really can't look at the world except through the bottom of glass filled with religion.

Ethelred

Brevity is soul of wit but there are no wits at physorg so why be brief.

1000 is the limit Mr. Lincoln, you will have remove 479 words from your address.

A continuing campaign to convince Physorg that they do not want to emulate Youtube.
Ricochet
Sep 15, 2009
This comment has been removed by a moderator.
rab96
1 / 5 (2) Sep 17, 2009
It is a theory based on evidence that shows that life evolves.


Evidence? All we have is theoretical constructions, of which this article is just another one.
Ethelred
3 / 5 (4) Sep 17, 2009
Evidence?


Megatons of fossils. Lab studies and field studies. Genetic evidence. Biological evidence that make no sense except in terms of evolution.

None of which are mere constructs.

The article is about the origin of life and not evidence or even a theory of evolution.

If you think we don't have evidence your knowledge is faulty and likely based on religious sources like the Aggressively Ignorant at Answers In Genesis and other deniers of reality.

Ethelred

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