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

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

And still doesn't answer anything....

Where did those amino acids come from?

Re:Discussed Organic Material in Meteor

The idea that nucleic acids and other organic building blocks were delivered to Earth from a meteor is not new. In fact, I remember reading about that in a space book when I was 5.

Personally, I think that whether or not the "seeds of life" originated here or came here on a meteor is a stupid idea, as it's not where they came from that is even remotely interesting, but how they came to be in the first place. If they originated here, then an asteroid impact may have scattered them elsewhere, and there may be other bewildered life forms on other planets wondering where they came from, or vice versa. What difference does it make?

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.

Re:Discussed Organic Material in Meteor

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.

Re:Discussed Organic Material in Meteor

No, that book is an evolution (pardon the pun) of the theory of evolution. It deals with what happened (in RD's view) *after* the avalanche of life had been triggered.

What I was asking was, what was the first snowflake that started that avalanche. Wake me up when people have started caring about that, coz I don't see much discourse on that subject in the scientific media.

Re:Discussed Organic Material in Meteor

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.

This is good news!

It means that there is only a 50% chance we are edible for aliens!

God vs. ...that.

I have a feeling a creation vs. evolution flamewar is about to start. Creationists will be creationists, but everyone else just think for a second:

If you were an average joe, not even a stupid joe but an average joe, which honestly sounds more convincing: 1) A supreme being did it, or 2) blah blah amino acids blah blah meteorites blah blah neutron star light rays blah blah?

So y'know, take it easy on the creationists. They may not understand how science works, but when faced with an article like this, can you really blame them?

Re:God vs. ...that.

Well, you've actually hit on one of the main creationist talking points -- "what are the odds that we'd all have left-handed amino acids, instead of a random mix that wouldn't work?" I'd be intersted to hear how they respond. I'd imagine with the same response as always (God put it here), but who knows. A good theory of why left-handeness is preferred (at least among amino acids) is a pretty big deal.

Re:God vs. ...that.

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

Re:God vs. ...that.

Seems there's a lot of people out there who think that this or that scientific discovery will make all the creationists wake up and finally abandon creationism. Not going to happen. You just can't reason somebody out of something they weren't reasoned into in the first place.

Re:God vs. ...that.

Also called the Anthropic Principle

Re:God vs. ...that.

They may not understand how science works, but when faced with an article like this, can you really blame them?

Poorly written news articles don't excuse flawed thinking. One shouldn't depend on shallow news stories or vague religious texts for explanations of the physical world.

Re:God vs. ...that.

"A cosmic Jewish Zombie who was his own father can make you live forever if you symbolically eat his flesh and telepathically tell him you accept him as your master, so he can remove an evil force from your soul that is present in humanity because a rib-woman was convinced by a talking snake to eat from a magical tree."

vs.

"A rock from space covered in particular chemicals crashed into the earth three billion years ago, and through a process of self-replication and environmental pressure, these chemicals produced more complex molecular structures, leading to life as we know it."

Yeah, Christianity is so much more plausible.

Re:God vs. ...that.

For not being plausible, there sure are a lot of people calling on God to save them during moments of suffering and death.

Of course they do, God made them to suffer, so only God can make it stop. We're all victims, pleading with a serial killer before He finishes His grisly work.

Re:God vs. ...that.

WEll..... try here: http://objectiveministries.org/creation/sciencefair.html [objectiveministries.org] 1st Place: "Life Doesn't Come From Non-Life" Patricia Lewis (grade 8) did an experiment to see if life can evolve from non-life. Patricia placed all the non-living ingredients of life - carbon (a charcoal briquet), purified water, and assorted minerals (a multi-vitamin) - into a sealed glass jar. The jar was left undisturbed, being exposed only to sunlight, for three weeks. (Patricia also prayed to God not to do anything miraculous during the course of the experiment, so as not to disqualify the findings.) No life evolved. This shows that life cannot come from non-life through natural processes. 2nd Place: "Women Were Designed For Homemaking" Jonathan Goode (grade 7) applied findings from many fields of science to support his conclusion that God designed women for homemaking: physics shows that women have a lower center of gravity than men, making them more suited to carrying groceries and laundry baskets; biology shows that women were designed to carry un-born babies in their wombs and to feed born babies milk, making them the natural choice for child rearing; social sciences show that the wages for women workers are lower than for normal workers, meaning that they are unable to work as well and thus earn equal pay; and exegetics shows that God created Eve as a companion for Adam, not as a co-worker.

Re:God vs. ...that.

(Patricia also prayed to God not to do anything miraculous during the course of the experiment, so as not to disqualify the findings.

Oh man... I *so* want to be the one grading the projects and to sit down and talk with sweet little Patricia about her science experiment. I would be abundantly enthusiastic and impressed with all of her scientific work as I went over the various aspects of her project. I would be particularly impressed and particularly commend her on her thoroughness in considering that God could potentially interfere with the experiment and specifically praying to God not to do so...

then I would get a thoughtful look on my face, and say "hmmmmmmm......"

Hmmmmm, Patricia, your excellent work just made me think of something. I'm impressed by how you scientifically accounted for possible supernatural influence in the experiment, but are you certain you accounted for all such possible effects? You accounted for God, but is God the only potential influence? What about Satan? Did you scientifically account for Satan? What if a charcoal briquet, purified water, and a multi-vitamin *do* spontaneously create life when left in the sun, but what if Satan interfered and kept killing any such new life just because he wanted to invalidate your findings?

You've done some excellent science work so far Patricia, and I don't want to score you badly for the oversight and inconsistent treatment of supernatural influences, so I'm going to let you take your project back so you can fix it. Do a new write up addressing the problem, and possibly re-do the experiment if necessary, and then bring it back to me when the problem is solved.

Okay, I'm a cruel bastard with a twisted sense of humor. Chuckle.

-

Re:God vs. ...that.

"Before we can arrive at any *hard proof* of evolution, we will first need to know what it takes to create a self-replicating organism in the first place."

Evolution (and the evidence for it) does not depend (logically or otherwise) on the origin of life. It doesn't really matter if the first self-replicating organism developed in a pool on the beach or in a deep-sea thermal vent, if it came from a meteorite from somewhere else, or if God poofed it into existence.

To suggest that evolution depends on this in any way is just moving the goal posts around.

Space sperm

Makes sense in a way: the meteors are sperm, the Earth the egg, the orbital bombardment the BDSM.

Amino Delivery: Under 30 Eons or your money back

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??

So this is news?

The fact that meterorite showers brought life to our planet is no mystery to me. See, I lived in Smallville for a while and I've seen things you wouldn't believe.

- Chloe Sullivan

Preventing Unwanted Earths

Now that we know that life as we know it sprang from meteorite-sperm, we owe it to the rest of the Universe to immediately deploy Dyson condoms.

Thought it had already been explained

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:Thought it had already been explained

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:Thought it had already been explained

I at least can recall the following. We have plenty of stereospecific molecules to the extent that sometimes the lefthanded molecule of something is good for us while the righthanded variant is poisonous. It doesn't mean that for every molecule in nature only one handedness will occur. Amino acids are nearly always lefthanded. Google for "homochirality".

If we create a mirror case for the current biological condition where all lefthanded molecules are replaced by righthanded and vice versa, this condition would be equally plausible.

The idea of symmetry breaking is that each of the conditions is equally plausible but mutually exclusive, and that a small perturbation early on would magnify to result in complete dominance of one variant. The origin of this perturbation is trivial, a butterfly flapping its wings if you wish, the important thing is the magnifying effect.

Parent post refers to a modification of that idea, where the two conditions are not exactly similar but there is actually a slight preference for one of the conditions. In the first case on half of the planets with life will have lefthanded life, the other half will have righthanded life. In the second case, all life is lefthanded.