Meteorites May Have Delivered Seeds of Life On Earth

esocid writes "At the national meeting of the American Chemical Society, 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 result of that brew could be the dominance of "left-handed" amino acids, the building blocks of life on this planet. 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. 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."

Discussed Organic Material in Meteor

[eldavojohn]

We discussed something similar to this here [slashdot.org] where they found organic molecules in a Canadian meteor.

Thought it had already been explained

[MrKevvy]

Someone correct me if I'm wrong, but I was under the impression that the left-handed chirality bias had already been explained by the non-conservation of parity in the electroweak force. The L enantiomers have a slightly lower binding energy, so in any mole of racemic amino acids you'll have about a million excess on the L side, which is enough to tip the balance.

Re:God vs. ...that.

[WaltBusterkeys]

I'm trying to understand why the above is a troll. This is a big deal theory.

Re:Thought it had already been explained

[MrKevvy]

re: "Citation?"

TY - JOUR
JO - Molecular Physics
PB - Taylor & Francis
AU - Tranter, G. E.
TI - The parity violating energy differences between the enantiomers of -amino acids
SN - 0026-8976
PY - 1985
VL - 56
IS - 4
SP - 825
EP - 838
UR - http://www.informaworld.com/10.1080/00268978500102741 [informaworld.com]

Re:God vs. ...that.

[Peaker]

Anything that can be created by evolution

Evolution is not the origin of life, it is the origin of species.

The origin of life is thought to be some event whereby a self-copying structure was formed. Many believe this event is extremely rare. Perhaps it happens so rarely, that on one out of trillions of planets, in one of trillions of seconds, it happened by chance.

It is possible that this event cannot reasonably be catalyzed in a non-intrusive way. For example, maybe you can increase the odds by a factor of many millions, by putting forth the correct chemicals, but you might still be a factor of billions behind if some rare reaction is necessary. If you try to catalyze it by causing the chemical reaction then the experiment may lose credibility.

Re:Discussed Organic Material in Meteor

[ampathee]

What I want to know is how complex organic molecules were formed into self-organising, self-replicating structures. Bigfoot is not the missing link. How we got to elemental material spewed out from a supernova to DNA, *that's* the missing link.

For the answer, I recommend you read "The Selfish Gene" by Richard Dawkins. It's a very well written and interesting book which answers that exact question. I just finished it a couple of months ago.

You're doing it wrong

[dreamchaser]

I don't see much discourse on that subject in the scientific media.

You mean in popular scientific media. The origin of the first life is a very hot topic amongst those in biological disciplines, and there are several competing theories. I suggest you start with a bit of reading on Abiogenesis [wikipedia.org] on Wikipedia. You'll find quite a few relevant citations as well as a discussion of past and current models.

Re:God vs. ...that.

[drerwk]

Also called the Anthropic Principle

Re:God vs. ...that.

[db32]

The main creationist talking point stems from a piss poor understanding of math and probability as well. My favorite explanation was actually Douglas Adams. It had to do with since a point has 0 dimensions there is an infinite number of points on a dart board. The tip of a dart represents a single point. When you throw the dart at the dart board and you calculate the probability of the dart hitting any specific point you arrive at 1 / (infinite) and it becomes impossible to hit any specific point on a dart board. Yet the dart will still hit.

It seems funny to me that the whole thing stems from "the probability of that happening is so small that it couldn't possibly happen". No...the probability of that happening is so small that it makes it a near miracle that it happened. That is the whole damned point of probability. Determining the frequency of an event that COULD happen.