Humble beginnings. An experiment in the 1950s with primordial gases and sparks produced some of life's building blocks.
Credit: Ned Shaw/Indiana University/Science
Posted on 10/17/2008 11:08:42 PM PDT by neverdem
Humble beginnings. An experiment in the 1950s with primordial gases and sparks produced some of life's building blocks.
Credit: Ned Shaw/Indiana University/Science
A once-discarded idea about how life started on our planet has been given a new life of its own, thanks to a serendipitous find.
The story traces back to the early 1950s, when chemists Stanley Miller and Harold Urey of the University of Chicago in Illinois tried to recreate the building blocks of life under conditions they thought resembled those on the young Earth. The duo filled a closed loop of glass chambers and tubes with water and different mixes of hydrogen, ammonia, and methane--gases presumed at the time to be the main constituents of the atmosphere billions of years ago. Then, in an attempt to confirm a hypothesis that lightning may have triggered the origin of life, they zapped the mixture with an electrical current. The researchers then analyzed the gunk that began to collect after a few hours.
The residue contained traces of some of the amino acids that make up proteins. Their presence suggested that the molecular precursors of life could form through a simple electrochemical process. The problem was that theoretical models and analyses of ancient rocks eventually convinced scientists that Earth's earliest atmosphere was not rich in hydrogen.
Last year, after Miller's death, two of his former graduate students--geochemists Jim Cleaves of the Carnegie Institution of Washington (CIW) in Washington, D.C., and Jeffrey Bada of Indiana University, Bloomington--were examining samples left in their mentor's lab. They discovered the vials of products from the original experiment and decided to take a second look with updated technology. Using extremely sensitive mass spectrometers at NASA's Goddard Space Flight Center in Greenbelt, Maryland, Cleaves, Bada, and colleagues found traces of 22 amino acids in the experimental residues. That is about double the number originally reported by Miller and Urey and includes all of the 20 amino acids found in living things, the scientists report tomorrow in Science.
So could lightning have helped jump-start life on Earth? Possibly, Cleaves says. Although Earth's primordial atmosphere was not hydrogen-rich, as were the chambers in the Miller-Urey experiment, gas clouds from volcanic eruptions did contain the right combination of molecules. It is possible that volcanoes, which were much more active early in Earth's history, seeded our planet with life's ingredients. The big question is what happened next--how did those molecules turn into self-replicating organic compounds? "That's the frontier," Cleaves says, "and we're sort of stuck there."
The new study "highlights how easy it is to make the building blocks of life in plausible prebiotic conditions," says geochemist Robert Hazen of CIW, who was not involved in the research. At the same time, he says, the findings reinforce "the pioneering insight and experiments of Stanley Miller and Harold Urey."
No, that was God.
No!
Next question.
INTREP
*applause*
“Using extremely sensitive mass spectrometers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, Cleaves, Bada, and colleagues found traces of 22 amino acids in the experimental residues. That is about double the number originally reported by Miller and Urey and includes all of the 20 amino acids found in living things, the scientists report tomorrow in Science.”
I doubt the veracity of this claim. However, it will be very easy to reproduce the original experiment and verify if this can be repleted. No replication...no veracity. Besides, they still have the problem that these experiments produced racemic mixes of the amino acid (optical isomers). Only one isomer of all the 20 is found in life on this planet. That doesn’t fit well with the results. Another reason it was scraped.
Plus, as noted, proteins are not self replicating (don’t bring up prions because that is a different situation). DNA contains the code (Codons) for the sequence of amino acids that make up a protein. That code is transcribed into a messenger RNA which is then translated into protein (a sequence of amino acids) at a ribosome (an RNA and Protein body) in all cells types....both simple (prokaryotic) and more complex (eukaryotic). From a molecular biology point of view, the “secret” of life is DNA is transcribed to RNA which is then translated into protein. That is the Central Dogma since Watson and Crick. It is still pretty much accepted.
But Obama’d throw life away.
Subsequent work by Szostak has shown that ribozymes can catalyze template-directed ligation reactions that might, in principle, permit RNA replication. Recently, Noller has provided evidence suggesting that ribosomal RNA, without the help of proteins, can catalyze the peptide bond-forming step of protein synthesis. These experiments support the hypothesis that a biochemistry based on RNA alone preceded the familiar biochemistry based on nucleic acids and proteins.
Francis H. C. Crick
http://www.fasebj.org/cgi/reprint/7/1/238.pdf
How did molecules and the subsequent compounds obtain the knowledge and the initiative to form absurdly complex life forms with interdependent physical systems, a conscience, emotions and the ability to create art?
Hmmm...could it be...God?
Naw. Must have just been a bizarre series of accidents. /s
Found traces??? Does that mean they found the actual animo acids or did they find tracks that could have the potential to lead to these animo acids???
So it appears that whoever put animo acids in living things also put animo acids in non living things...
I wish these guys would move a little faster on the research tho...I'm really curious as to how and why my eyes were made...And what showed up first, my eyes or my brain...And my eyelids...How many billions of years did we have eyes but no eyelids to open to see thru them???
And what about eating??? When did the first little bug get a mouth??? And figure out it's good to eat other little bugs...
And I'm curious about mountain goats...Did they keep falling off mountains for a couple of billions of years til their little feet adapted to where they could climb the rocks???
In my view, discovering animo acids in non living things isn't all that big a deal...Now when they figure out what animo acids evolved from, that might be newsworthy...
Here's the other side of the issue...
Joh 1:3 All things were made by him; and without him was not any thing made that was made.
Joh 1:10 He was in the world, and the world was made by him, and the world knew him not.
Ecc 1:9 The thing that hath been, it is that which shall be; and that which is done is that which shall be done: and there is no new thing under the sun.
Ecc 8:17 Then I beheld all the work of God, that a man cannot find out the work that is done under the sun: because though a man labor to seek it out, yet he shall not find it; yea further; though a wise man think to know it, yet shall he not be able to find it.
Psa 139:14 I will praise thee; for I am fearfully and wonderfully made: marvelous are thy works; and that my soul knoweth right well.
Gen 2:7 And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.
“The big question is what happened next—how did those molecules turn into self-replicating organic compounds? “That’s the frontier,” Cleaves says, “and we’re sort of stuck there.”
It’s more the South Rim of the Grand Canyon. Even if I can see the other side I can’t get there by small steps.
The statement means that they found all the actual amino acids, but the the ones NOT reported in the original paper were present at levels below the detection limits of the techniques used in that paper.
"So it appears that whoever put animo acids in living things also put animo acids in non living things..."
No. What it means is that all those amino acids were formed in the original electrical discharge experiment. There WERE no amino acids present in the starting materials---that's the whole point.
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I have been told that scientists no longer believe the earth’s atmosphere started out with methane & ammonia. The combination of high temperature and low gravity (compared with those of Jupiter) would have allowed those light gasses to escape into space. If those theories are correct, what’s the point in repeating the experiment?
No, that was God.
Thank you!
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