We may just be aliens after all: Study

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Witchfinder General

punched Wheelchair Mike
Genetic material from outer space found in a meteorite in Australia may well have played a key role in the origin of life on Earth, according to a study to be published on Sunday.

European and US scientists have proved for the first time that two bits of genetic coding, called nucleobases, contained in the meteor fragment, are truly extraterrestrial.

Previous studies had suggested that the space rocks, which hit Earth some 40 years ago, might have been contaminated upon impact.

Both of the molecules identified, uracil and xanthine, "are present in our DNA and RNA," lead author Zita Martins, a researcher at Imperial College London, said.

RNA, or ribonucleic acid, is another key part of the genetic coding that makes up our bodies.

These molecules would also have been essential to the still-mysterious alchemy that somehow gave rise, some four billion years ago, to life itself.

"We know that meteorites very similar to the Murchison meteorite, which is the one we analysed, were delivering the building blocks of life to Earth 3.8 to 4.5 billion years ago," Dr Martins said.

Competing theories suggest that nucleobases were synthesised closer to home, but Dr Martins counters that the atmospheric conditions of early Earth would have rendered that process difficult or impossible.

A team of European and US scientists showed that the two types of molecules in the Australian meteorite contained a heavy form of carbon - carbon 13 - which could only have been formed in space.

"We believe early life may have adopted nucleobases from meteoric fragments for use in genetic coding, enabling them to pass on their successful features to subsequent generations," Dr Martins said.

If so, this would have been the start of an evolutionary process leading over billions of years to all the flora and fauna - including human beings - in existence today.

The study, published in Earth Planetary Science Letters, also has implications for life on other planets.

"Because meteorites represent leftover materials from the formation of the solar system, the key components of life - including nucleobases - could be widespread in the cosmos," said co-author Mark Sephton, also at Imperial College London.

"As more and more of life's raw materials are discovered in objects from space, the possibility of life springing forth wherever the right chemistry is present becomes more likely."

Uracil is an organic compound found in RNA, where it binds in a genetic base pair with another molecule, adenine.

Xanthine is not directly part of RNA or DNA, but participates in a series of chemical reactions inside the RNA of cells.

The two types of nucleobases and the ratio of light-to-heavy carbon molecules were identified through gas chromatography and mass spectrometry, technologies that were not available during earlier analyses of the now-famous meteorite.

Even so, Dr Martins said, the process was extremely laborious and time-consuming, one reason it had not be carried out up to now by other scientists.
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Source: http://www.abc.net.au/news/stories/2008/06/14/2274877.htm

So very cool.
 
I think it's just as probable as the idea life arose spontaneously on earth. But I remember when this idea was just a crackpot theory.
 
xf1x04.jpg



I told you so!
 
Witchfinder General said:
A team of European and US scientists showed that the two types of molecules in the Australian meteorite contained a heavy form of carbon - carbon 13 - which could only have been formed in space.
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One thing, C13 is found on the earth. About 1 percent of earth's carbon is C13. I'm sure they'll be more details tomorrow to indicate what's special about their C13 detection.. like maybe half of the carbon was C13... but this alone doesn't tell me much.
 
Little do we know that the Aliens have observed what has become of this planet and they have lobbed another meteorite to destroy it all.

Operation: My bad!
 
I still believe in Stanley Miller's original hypothesis on this matter. Chemical evolution makes sense in the context of early earth if you consider the millions of years theorists give as a time frame for the formation of even the simplest peptide. We already know that RNA can form under the conditions of early earth (from that experiment). We know RNA has catalytic activity in protein synthesis. The jump from simple RNA to complex proteins and DNA can be made without considering extraterrestrial origin.

It's intriguing that they found purine compounds in a meteorite, though. It shows that the meteorite came from a place with a climate and atmosphere similar to ours. It's too bad the original article doesn't list which journal this paper is from.
 
Razkolnikov said:
I still believe in Stanley Miller's original hypothesis on this matter. Chemical evolution makes sense in the context of early earth if you consider the millions of years theorists give as a time frame for the formation of even the simplest peptide. We already know that RNA can form under the conditions of early earth (from that experiment). We know RNA has catalytic activity in protein synthesis. The jump from simple RNA to complex proteins and DNA can be made without considering extraterrestrial origin.
It's intriguing that they found purine compounds in a meteorite, though. It shows that the meteorite came from a place with a climate and atmosphere similar to ours. It's too bad the original article doesn't list which journal this paper is from.
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This jump is incredible. The specific chains involved are so complex it would take hundreds of times the age of the the earth to develop by random chance. The only reason scientists are looking to outerspace for DNA origin is because they know this. The time line doesn't work, it's too complex for 4 billion years.
 
I was hoping for something a little more alien I guess.

I mean, the planet was formed of interstellar matter too. I was hoping to see like "CRO MAGNON MAN FROM EXTRASOLAR ATLANTIS" or something. Of course we come from space, where you draw the line on that is arbitrary... I dunno, I guess if you have "native" RNA and it gets jumpstarted by an infusion of alien jizz, that's pretty cool. I just had my expectations too high. :D
 
Ela Hadrun said:
I was hoping for something a little more alien I guess.

I mean, the planet was formed of interstellar matter too. I was hoping to see like "CRO MAGNON MAN FROM EXTRASOLAR ATLANTIS" or something. Of course we come from space, where you draw the line on that is arbitrary... I dunno, I guess if you have "native" RNA and it gets jumpstarted by an infusion of alien jizz, that's pretty cool. I just had my expectations too high. :D
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Yeah, I mean, given the Drake equations, it's more or less 100% certain tht there is pleeeeenty of organic life out there, so whether or not panspermia is true seems to me to be almost... irrelevant o_O
 
Batmonk said:
This jump is incredible. The specific chains involved are so complex it would take hundreds of times the age of the the earth to develop by random chance. The only reason scientists are looking to outerspace for DNA origin is because they know this. The time line doesn't work, it's too complex for 4 billion years.
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RNA can chemically take the place of protein or DNA and not just be an intermediate or assistant, so it's quite plausible it's what was around before the two roles became specialized. It didn't have to start out complex either, just a basic chemical engine in a cell wall.

After all, gene coding itself has evolved over time, and it took 3 billion years to get single-celled life to where it is today.
 
Hitokage said:
RNA can chemically take the place of protein or DNA and not just be an intermediate or assistant, so it's quite plausible it's what was around before the two roles became specialized. It didn't have to start out complex either, just a basic chemical engine in a cell wall.
After all, gene coding itself has evolved over time, and it took 3 billion years to get single-celled life to where it is today.
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I'll give you the engine, but you've already put it in the car. Who's cell wall are we speaking of?
But that's not the whole puzzle. RNA or protein strands still have a levels of complexity that cannot be explained by "random chance x years". The base chemicals are there, but they have to be in the right order to become proteins, then those proteins have to be in the right order to become DNA, then the DNA has to be in the right order to be self-replicating. The jump from base chemicals to life-forms is bigger than most people are willing to admit.
 
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