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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."
Interesting read. It has been one of the more pressing questions of the theory of biogenesis: where did the first organic matter come from? I have always found chirality and the left-handed nature of Earth's proteins to be more than mere coincidence.
It is strange that our location in the galaxy led to a slight imbalance in the amount of gravitationally polarized light striking chunks of rock and metal floating in a cosmic dance 4 billion years before I was born....yet that combination of factors resulted in the alanine in my body to contain only the left-handed chiral.
Studies like this are the cause of my personal religious dilemma. Most of the major religions came about 1500-5000 years ago...and at the time they were conceived, they convincingly explained every natural occurrence well enough to placate the masses. I wonder what the Pope would have to say about this study...was God a southpaw??
khasim (12/9/06): In a blind taste test, more people preferred Coke over the Pepsi that I had previously pissed in.
"what are the odds that we'd all have left-handed amino acids..."
In econometrics, I learned this to be "Sample Selection Bias". The odds that we'd all have left-handed amino acids might be nill. However, the odds that we'd all have left-handed amino acids GIVEN that we've become conscious beings able to analyze such a thing?
I mean, maybe there WERE a lot of failures. But somewhere in the universe, ONE worked. And BECAUSE we worked, we're able to wonder about it.
Maybe complex organic molecules form into self-organising self replicating structures BECAUSE they were delivered from elsewhere. The two need not be mutually exclusive.
What if the "seeds" of life require foreign interference to mutate into life. I don't understand how we can evaluate a missing link if we don't know where all the components came from. The Earth could have been an unfertilized egg waiting to be inseminated. For that reason how they came to be is just as interesting as where they came from especially if they are intertwined.
Imagine the odds that would have to be overcome if it takes a specific type of meteor to react with a specific type of dead planet to make life. If that is true the odds of the right elements being present in both cases could be so high that they could be conceivably called divine. It would be pretty funny as well if the chain reaction took 7 days.