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Meteorites delivered the 'seeds' of Earth's left-hand life
American Chemical Society ^ | April 6, 2008 | Unknown

Posted on 04/06/2008 7:15:15 AM PDT by decimon

NEW ORLEANS, April 6, 2008—Flash back three or four billion years — Earth is a hot, dry and lifeless place. All is still. Without warning, a meteor slams into the desert plains at over ten thousand miles per hour. With it, this violent collision may have planted the chemical seeds of life on Earth.

Scientists presented evidence today that desert heat, a little water, and meteorite impacts may have been enough to cook up one of the first prerequisites for life: The dominance of “left-handed” amino acids, the building blocks of life on this planet.

In a report at the 235th national meeting of the American Chemical Society, Ronald Breslow, Ph.D., University Professor, Columbia University, and former ACS President, described how our amino acid signature came from outer space.

Chains of amino acids make up the protein found in people, plants, and all other forms of life on Earth. There are two orientations of amino acids, left and right, which mirror each other in the same way your hands do. This is known as “chirality.” In order for life to arise, proteins must contain only one chiral form of amino acids, left or right, Breslow noted.

“If you mix up chirality, a protein’s properties change enormously. Life couldn’t operate with just random mixtures of stuff,” he said.

With the exception of a few right-handed amino acid-based bacteria, left-handed “L-amino acids” dominate on earth. The Columbia University chemistry professor said that amino acids delivered to Earth by meteorite bombardments left us with those left-handed protein units.

“These meteorites were bringing in what I call the ‘seeds of chirality,’” stated Breslow. “If you have a universe that was just the mirror image of the one we know about, then in fact, presumably it would have right-handed amino acids. That’s why I’m only half kidding when I say there is a guy on the other side of the universe with his heart on the right hand side.”

These amino acids “seeds” formed in interstellar space, possibly on asteroids as they careened through space. At the outset, they have equal amounts of left and right-handed amino acids. But as these rocks soar past neutron stars, their light rays trigger the selective destruction of one form of amino acid. The stars emit circularly polarized light—in one direction, its rays are polarized to the right. 180 degrees in the other direction, the star emits left-polarized light.

All earthbound meteors catch an excess of one of the two polarized rays. Breslow said that previous experiments confirmed that circularly polarized light selectively destroys one chiral form of amino acids over the other. The end result is a five to ten percent excess of one form, in this case, L-amino acids. Evidence of this left-handed excess was found on the surfaces of these meteorites, which have crashed into Earth even within the last hundred years, landing in Australia and Tennessee.

Breslow simulated what occurred after the dust settled following a meteor bombardment, when the amino acids on the meteor mixed with the primordial soup. Under “credible prebiotic conditions”— desert-like temperatures and a little bit of water — he exposed amino acid chemical precursors to those amino acids found on meteorites.

Breslow and Columbia chemistry grad student Mindy Levine found that these cosmic amino acids could directly transfer their chirality to simple amino acids found in living things. Thus far, Breslow’s team is the first to demonstrate that this kind of handedness transfer is possible under these conditions.

On the prebiotic Earth, this transfer left a slight excess of left-handed amino acids, Breslow said. His next experiment replicated the chemistry that led to the amplification and eventual dominance of left-handed amino acids. He started with a five percent excess of one form of amino acid in water and dissolved it.

Breslow found that the left and right-handed amino acids would bind together as they crystallized from water. The left-right bound amino acids left the solution as water evaporated, leaving behind increasing amounts of the left-amino acid in solution. Eventually, the amino acid in excess became ubiquitous as it was used selectively by living organisms.

Other theories have been put forth to explain the dominance of L-amino acids. One, for instance, suggests polarized light from neutron stars traveled all the way to earth to “zap” right-handed amino acids directly. “But the evidence that these materials are being formed out there and brought to us on meteorites is overwhelming,” said Breslow.

The steps afterward that led towards the genesis of life are shrouded in mystery. Breslow hopes to shine more light on prebiotic Earth as he turns his attention to nucleic acids, the chemical units of DNA and its more primitive cousin RNA.

“This work is related to the probability that there is life somewhere else,” said Breslow. “Everything that is going on on Earth occurred because the meteorites happened to land here. But they are obviously landing in other places. If there is another planet that has the water and all of the things that are needed for life, you should be able to get the same process rolling.”

###

Please visit http://portal.acs.org/portal/acs/corg/content?_nfpb=true&_pageLabel=PP_ARTICLEMAIN&node_id=222&content_id=WPCP_008688&use_sec=true&sec_url_var=region1 for our press briefings schedule.

The American Chemical Society — the world’s largest scientific society — is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.


TOPICS: Culture/Society; News/Current Events; Technical
KEYWORDS: ajntsa; awjeeznotthisagain; catastrophism; godsgravesglyphs; panspermia; xplanets
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Cool. I'm left-handed.
1 posted on 04/06/2008 7:15:15 AM PDT by decimon
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To: decimon

Woo hoo! Left-handers dominate!


2 posted on 04/06/2008 7:18:29 AM PDT by mtbopfuyn (The fence is "absolutely not the answer" - Gov. Rick Perry (R, TX))
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To: decimon
The Columbia University chemistry professor said that amino acids delivered to Earth by meteorite bombardments left us with those left-handed protein units.

If that's true then why is only 3% of the world population left handed? Lefties have been and are discriminated against! I want an investigation! ;O)
3 posted on 04/06/2008 7:21:03 AM PDT by Man50D (Fair Tax, you earn it, you keep it!)
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To: decimon
There need be no underlying scientific explanation for the dominance of left handed amino acids any more than there was a underlying scientific explanation for the dominance of VCR’s over Beta-max.

Once one got a little more popular, for whatever reason, everybody wanted “in” on the game.

Moreover there are still right handed amino acid using life forms extant upon the earth. And amino acids form just fine by natural synthesis here on earth, there is no prerequisite for “amino acids FROM SPAAAAACE!” and I'm not sure a 10 to 20% bias towards left handed amino acids caused by meteorites being exposed to polarizing light added to the pool of terrestrial amino acids has much explanatory power.

Just my 0.02.

4 posted on 04/06/2008 7:28:36 AM PDT by allmendream
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To: decimon

Humm, does this explain why college professors swing left?


5 posted on 04/06/2008 7:28:52 AM PDT by RouxStir (No Peeing Allowed in the Gene Pool.)
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To: Man50D
Lefties have been and are discriminated against! I want an investigation!

The investigation found 'lefties' have a hanging chad in their DNA.
6 posted on 04/06/2008 7:32:20 AM PDT by presently no screen name
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To: decimon

Fairy tales.


7 posted on 04/06/2008 7:33:32 AM PDT by RoadTest ( None calleth for justice, nor any pleadeth for truth: they trust in vanity, and speak lies - Isaiah)
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To: decimon

Maybe Q was right.


8 posted on 04/06/2008 7:34:38 AM PDT by BigCinBigD (")
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To: decimon

Hmm. I use both hands interchangeably. I’m amphibious.


9 posted on 04/06/2008 7:35:58 AM PDT by Lancey Howard
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To: decimon
“These meteorites were bringing in what I call the ‘seeds of chirality,’” stated Breslow. “If you have a universe that was just the mirror image of the one we know about, then in fact, presumably it would have right-handed amino acids. That’s why I’m only half kidding when I say there is a guy on the other side of the universe with his heart on the right hand side.”

Don't need a mirror image universe. If the guy lives in a town of 10,000 folks, about ten of them have their heart biased to the right side of the chest.

10 posted on 04/06/2008 7:36:46 AM PDT by jwalsh07 (Obama, the King of Hope-a-Dope)
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To: presently no screen name
The investigation found 'lefties' have a hanging chad in their DNA.

Allegedly found by who? Righties?
11 posted on 04/06/2008 7:38:24 AM PDT by Man50D (Fair Tax, you earn it, you keep it!)
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To: Lancey Howard

LOL


12 posted on 04/06/2008 7:39:25 AM PDT by grjr21
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To: decimon

BS. Postulating that life on Earth arrived through a meteorite pushes the explanation for life on to an impossible-to-determine other planet.
Stupid.
It arose on Earth.


13 posted on 04/06/2008 7:41:23 AM PDT by Leftism is Mentally Deranged
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To: decimon

A fascinating theory. It must be nearly impossible to prove this. I suppose some meteors will need to be isolated before they become meteorites. One would have to examine meteors before they become “contaminated” by the Earth and its atmosphere. Right now, such a thing is the stuff of science fiction.


14 posted on 04/06/2008 7:43:16 AM PDT by plan2succeed.org (www.SafeLibraries.org)
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To: decimon
From The American Society of Imbibing Too Many Chemicals”, “It all came from meteorites! How do I know? Because I just said it did and that's proof enough for me. Research? I'll check what I said. Yep, research confirms what I said. Now write up a study and..blah,blah, blah.”
15 posted on 04/06/2008 7:54:19 AM PDT by count-your-change (you don't have to be brilliant, not being stupid is enough.)
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To: SunkenCiv; blam

Southpaws-are-better-than-you-are ping.


16 posted on 04/06/2008 7:56:01 AM PDT by decimon
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To: decimon

I remember when this happened.


17 posted on 04/06/2008 7:57:29 AM PDT by Conspiracy Guy (I voted Republican because no Conservatives were running.)
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To: Lancey Howard
I’m amphibious.

Should I be so gullible as to believe you are gillable?

18 posted on 04/06/2008 8:00:55 AM PDT by decimon
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To: Leftism is Mentally Deranged
BS. Postulating that life on Earth arrived through a meteorite pushes the explanation for life on to an impossible-to-determine other planet. Stupid. It arose on Earth.

Hey! What happened to the old chestnut about the comet that hits the Earth, melts, and then a bolt of lightning starts the Life Cycle chain???

But I have to agree with you. It's ironic that we have to have faith in these scientists that (the seeds of) life began somewhere else, was blown into outer space, and somehow found our world.

Yeah! Yeah! That's a LOT easier to swallow than a belief in God! /s

It's always something--anything--else.

19 posted on 04/06/2008 8:02:19 AM PDT by BradyLS (DO NOT FEED THE BEARS!)
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To: RoadTest

Why?


20 posted on 04/06/2008 8:02:52 AM PDT by tokenatheist (Can I play with madness?)
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To: BradyLS

How do you know that this isn’t the way your deity placed life on Earth?


21 posted on 04/06/2008 8:04:01 AM PDT by tokenatheist (Can I play with madness?)
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To: decimon

Just because he said it does not make it true.


22 posted on 04/06/2008 8:04:45 AM PDT by Piquaboy (22 year veteran of the Army, Air Force and Navy, Pray for all our military .)
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To: Conspiracy Guy
I remember when this happened.

No, no, this is more about RNA than LSD.

23 posted on 04/06/2008 8:04:48 AM PDT by decimon
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To: decimon

I didn’t know proteins have “hands.” Do they also have “arms”, “legs”, “heads”, “torso”, and “feet”?


24 posted on 04/06/2008 8:05:57 AM PDT by WashingtonSource
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To: BradyLS

...Point is, whether one believes in God or not, it’s ironic that scientists want to push a more preposterous theory for the origins of life on Earth onto some other world where an even freakier chain of random events brings it here!

It can’t be proven. Ya just have to believe!


25 posted on 04/06/2008 8:07:21 AM PDT by BradyLS (DO NOT FEED THE BEARS!)
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To: decimon
More 'Science Fiction'.

Geeze, will there ever be an end to junk science being presented as fact.

26 posted on 04/06/2008 8:07:24 AM PDT by Dustbunny (Freedom prospers when religion is vibrant and the rule of law under God is acknowledged. The Gipper)
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To: decimon
“If you mix up chirality, a protein’s properties change enormously. Life couldn’t operate with just random mixtures of stuff,” he said.


But I thought their entire premise was that the origins of the universe, as well as life on earth, were the result of random events.
27 posted on 04/06/2008 8:08:21 AM PDT by rottndog (Let us NEVER FORGET those that have paid the HIGHEST PRICE for our FREEDOM!)
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To: decimon

Wow dude.


28 posted on 04/06/2008 8:08:45 AM PDT by Conspiracy Guy (I voted Republican because no Conservatives were running.)
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To: tokenatheist

No, YOU PROVE that life began on some other world and was blown clear over here.


29 posted on 04/06/2008 8:09:20 AM PDT by BradyLS (DO NOT FEED THE BEARS!)
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To: Leftism is Mentally Deranged
It arose on Earth.

Since nobody knows and the evidence was eaten, such an assertion is not disproveable. FR would shrivel up and die without such non logic.

30 posted on 04/06/2008 8:10:08 AM PDT by RightWhale (Clam down! avoid ataque de nervosa)
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To: BradyLS

Is yelling really necessary?


31 posted on 04/06/2008 8:10:44 AM PDT by tokenatheist (Can I play with madness?)
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To: tokenatheist

Is that all you got?


32 posted on 04/06/2008 8:13:04 AM PDT by BradyLS (DO NOT FEED THE BEARS!)
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To: BradyLS

‘It can’t be proven. Ya just have to believe!’

That isn’t how science works however that is how religion works.


33 posted on 04/06/2008 8:13:44 AM PDT by tokenatheist (Can I play with madness?)
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To: BradyLS

You didn’t address my original question and I have no intention of getting into a shouting match with someone who simply wants to stir up trouble.

If you feel that you can debate in an honest and respectful way I will be available.


34 posted on 04/06/2008 8:14:54 AM PDT by tokenatheist (Can I play with madness?)
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To: tokenatheist

You make my point. This bunch just wants us to believe them. That’s no sort science.


35 posted on 04/06/2008 8:16:57 AM PDT by BradyLS (DO NOT FEED THE BEARS!)
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To: tokenatheist

When you can prove what these scientists assert, I’ll believe you.


36 posted on 04/06/2008 8:18:13 AM PDT by BradyLS (DO NOT FEED THE BEARS!)
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To: BradyLS

Please point out were I said that I support this theory.


37 posted on 04/06/2008 8:19:25 AM PDT by tokenatheist (Can I play with madness?)
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To: tokenatheist

Please point to which deity I supported.


38 posted on 04/06/2008 8:20:00 AM PDT by BradyLS (DO NOT FEED THE BEARS!)
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To: BradyLS

I assume the Christian god seeing as how you capitalized the G which is the custom of Christians.

I can rule out Islam and Judaism using that same sort of reasoning.


39 posted on 04/06/2008 8:23:39 AM PDT by tokenatheist (Can I play with madness?)
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To: decimon
Meteorites? I thought it was the Amish.
40 posted on 04/06/2008 8:25:55 AM PDT by ThomasThomas (Birthdays don't make you Old.iiiiiiiiii..It's the 364 days between them.)
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To: Conspiracy Guy

I’m still going with the Marooned Space Alien theory.
It’s more colorful.


41 posted on 04/06/2008 8:31:07 AM PDT by tet68 ( " We would not die in that man's company, that fears his fellowship to die with us...." Henry V.)
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To: tokenatheist

Let’s proceed that you are correct. If “scientists” are going to push their theories into the realm of faith (because it can’t be proved or reproduced) well that’s just religion, too. The Bible doesn’t say that’s how it happened. Whatever happened, happened here. If that’s my choice, I’ll simply go with God.


42 posted on 04/06/2008 8:38:38 AM PDT by BradyLS (DO NOT FEED THE BEARS!)
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To: tet68

Well that was several years later. Before the meteorite hit in the dry still desert all my friends and I were just free floating subatomic particles. Suddenly we began to develop molecular structure and we were thankful for that. First we ate dust but in time we had dirt to eat. Mud followed and that was a real treat.

We didn’t have much but we were thankful for what we had. We knew many who had less and we shared as much as we could. In time we all were able to divide our cells and prosper.


43 posted on 04/06/2008 8:53:05 AM PDT by Conspiracy Guy (I voted Republican because no Conservatives were running.)
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To: Man50D
found by who

By those that need a reason for non important things in life.
44 posted on 04/06/2008 8:56:54 AM PDT by presently no screen name
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To: BradyLS
The Bible doesn’t say that’s how it happened. Whatever happened, happened here. If that’s my choice, I’ll simply go with God.

The concept of building blocks of life, or even of life itself (panspermia) coming to earth from meteorites is not inconsistent with God creating life.

It is one of many possible mechanisms God could have used.

45 posted on 04/06/2008 9:20:31 AM PDT by CurlyDave
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To: Leftism is Mentally Deranged

By U/Pb-Th/Pb isotope ratios it seems that meteors originiated concomitant with the Sun. Thus those scientists who will, are left with still having to thrash about to discern what God wrought. Though I doubt they ever will, since discovering life’s beginnings necessarily also means discovering its end.


46 posted on 04/06/2008 9:27:22 AM PDT by onedoug
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To: BradyLS
I’ll simply go with God.

Yes, because God is the only Truth there is - The Creator, All Knowing. Yet man with his 5 natural senses, DAILY and ever changing, comes up w/what 'they think'. Prideful man says, "I'm smart - I have the answers". Natural man with his carnal mind trying to understand what was done supernaturally is laughable.
47 posted on 04/06/2008 9:28:03 AM PDT by presently no screen name
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To: decimon

Interesting hypothesis. The fact that the preponderance of amino acids found in those meteorites were of the left-sided type certainly suggests its a possibility. But, lets see where it goes from here.


48 posted on 04/06/2008 9:30:51 AM PDT by Youngblood
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To: BradyLS

These scientists are coming up with hypotheses based on evidence that they’re finding on meteorites or in the lab. Whether those hypotheses stand in the long run remains to be seen, as further experiments are carried out and new data is considered. That is how science works. Religion has nothing to do with it except that it seems to upset some people’s religious sensibilities that scientists have the audacity to actually tackle questions such as these in the first place.


49 posted on 04/06/2008 9:36:53 AM PDT by Youngblood
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To: decimon
"These amino acids “seeds” formed in interstellar space, possibly on asteroids as they careened through space."

'Splain me sometin':

Why would it be easier for amino acids to form on lifeless asteroids than on lifeless earth?

50 posted on 04/06/2008 9:44:52 AM PDT by cookcounty (Obama reach across the aisle? He's so far to the left, he'll need a roadmap to FIND the aisle.)
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