Progress in origin of life research - RNA world

[rwatts]

Layperson’s writeup:-

Scientists solve the 'chicken and the egg' conundrum for life’s beginnings

Paper:-

Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism

[oxmixmudd]

Layperson’s writeup:-

Scientists solve the 'chicken and the egg' conundrum for life’s beginnings

Paper:-

Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism

interesting ...

[shunyadragon]

Layperson’s writeup:-

Scientists solve the 'chicken and the egg' conundrum for life’s beginnings

Paper:-

Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism

Neat!!!

[rwatts]

interesting ...

It's darn chemistry though, and I could never really get the hang of that subject, for some reason.

[Omniskeptical]

RNA doesn't reproduce without a ribosome.

[shunyadragon]

RNA doesn't reproduce without a ribosome.

This occurs in complex cells, and does not apply in the primitive situation proposed.

[Epoetker]

Absolutely nothing in the lay or "scientific" writeup is new or relevant. The occasional production of organic building blocks in a chemical soup was never in theoretical doubt, what was in doubt was that those building blocks could ever come together to form self-replicating organisms that gave natural selection something to select:

The perceived differences and incompatibilities between these subsystems have led to the widely held assumption that one or other subsystem must have preceded the others. Here we experimentally investigate the validity of this assumption by examining the assembly of various biomolecular building blocks from prebiotically plausible intermediates and one-carbon feedstock molecules. We show that precursors of ribonucleotides, amino acids and lipids can all be derived by the reductive homologation of hydrogen cyanide and some of its derivatives, and thus that all the cellular subsystems could have arisen simultaneously through common chemistry.

The relevant details of the GROUNDBREAKING article that supposedly ROCKS MY ORIGIN-OF-LIFE WORLD is of course behind a paywall, but the Pretty Pictures accompanying the article indicates that is probably isn't going to address things like "concentration necessary for these reactions to succeed", "impurities that would make other chemical reactions more likely", "environmental states preventing hydrolysis and reversibility of reactions among the substrate components" and other things that chemists with an actual job would in fact be very interested in indeed. OOL press releases are, as they always have been since the Miller and Urey experiments, popular voodoo for unquestioning midwits who'll pay good money for whatever passes as science journalism.

[Omniskeptical]

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[klaus54]

National Vaccine Information Center

http://www.mentalhealthamerica.net/

Source: http://www.cdc.gov/Features/PolioFacts/

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[rwatts]

Layperson’s writeup:-

Scientists solve the 'chicken and the egg' conundrum for life’s beginnings

Paper:-

Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism

Even more recent stuff:-

Layperson's writeup:-

New study hints at spontaneous appearance of primordial DNA

Paper:-

Abiotic ligation of DNA oligomers templated by their liquid crystal ordering

[Epoetker]

Abiotic ligation of DNA oligomers templated by their liquid crystal ordering

The idiotic assumptions write themselves in the first sentence:

"concentrated solutions of short DNA oligomers develop liquid crystal ordering as the result of a hierarchically structured supramolecular self-assembly."

Do you know why the smart money was on the RNA world hypothesis in the first place? It's because DNA IS TOO STABLE A MACROMOLECULE TO CATALYZE OR EVEN TEMPLATE ITS OWN REPRODUCTIVE CYCLE WITHOUT THE AID OF HELPER MOLECULES ADAPTED TO THE TASK.

Leaving aside the likelihood of the creation and concentration of the DNA Lincoln Logs they postulate here, there is no reproductive mechanism outside of MEGA-GLOMMING:

"In the presence of abiotic condensing agents, liquid crystal ordering markedly enhances ligation efficacy, thereby enhancing its own phase stability. The coupling between order-templated ligation and selectivity provided by supramolecular ordering enables an autocatalytic cycle favouring the growth of DNA chains, up to biologically relevant lengths, from few-base long oligomers."

What's the over-under on pulling those hypothetical DNA globs out to form something protein-wise?

"This finding suggests a novel scenario for the abiotic origin of nucleic acids."

It was never about finding possible abiotic orgins for organic compounds, it was about whether those compounds could seriously expect to arise in a form subject to mutation and selection, given what we know about the behavior of those molecules in solution. The images are already a minefield of assumptions:

ncomms7424-f1.jpg

Hmmm, yes, I'll assume that the primordial soup was able to magick me up a situation where each individual building block is a stable and symmetrical 12-base DNA pair with matching 3' ends, then I'm going to assume that it concentrated the agent that allows these sweet balanced building blocks to actually react together to form my biological superstructure, no need for God here, no siree.

[HMS_Beagle]

The idiotic assumptions write themselves in the first sentence:

"concentrated solutions of short DNA oligomers develop liquid crystal ordering as the result of a hierarchically structured supramolecular self-assembly."

Do you know why the smart money was on the RNA world hypothesis in the first place? It's because DNA IS TOO STABLE A MACROMOLECULE TO CATALYZE OR EVEN TEMPLATE ITS OWN REPRODUCTIVE CYCLE WITHOUT THE AID OF HELPER MOLECULES ADAPTED TO THE TASK.

Leaving aside the likelihood of the creation and concentration of the DNA Lincoln Logs they postulate here, there is no reproductive mechanism outside of MEGA-GLOMMING:

"In the presence of abiotic condensing agents, liquid crystal ordering markedly enhances ligation efficacy, thereby enhancing its own phase stability. The coupling between order-templated ligation and selectivity provided by supramolecular ordering enables an autocatalytic cycle favouring the growth of DNA chains, up to biologically relevant lengths, from few-base long oligomers."

What's the over-under on pulling those hypothetical DNA globs out to form something protein-wise?

"This finding suggests a novel scenario for the abiotic origin of nucleic acids."

It was never about finding possible abiotic orgins for organic compounds, it was about whether those compounds could seriously expect to arise in a form subject to mutation and selection, given what we know about the behavior of those molecules in solution. The images are already a minefield of assumptions:

Hmmm, yes, I'll assume that the primordial soup was able to magick me up a situation where each individual building block is a stable and symmetrical 12-base DNA pair with matching 3' ends, then I'm going to assume that it concentrated the agent that allows these sweet balanced building blocks to actually react together to form my biological superstructure, no need for God here, no siree.

Awesome "scientific" rebuttal there Bro, especially the clever use of shouting giant capital letters. Why don't you write it up and submit it to Nature Chemistry? Just be sure to post their whole reply to you here.

[rwatts]

Awesome "scientific" rebuttal there Bro, especially the clever use of shouting giant capital letters. Why don't you write it up and submit it to Nature Chemistry? Just be sure to post their whole reply to you here.

My thoughts entirely.

In Jorge's absence, it's nice to have another ranter around.

I was going to reply but I have another paper to mention in the same way I have the others. So it's worth posting and watching a few more blood vessels pop.

[rwatts]

Layperson’s writeup:-

Scientists solve the 'chicken and the egg' conundrum for life’s beginnings

Paper:-

Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism

Anotheree:-

Abstract:-

Meteorite-catalyzed syntheses of nucleosides and of other prebiotic compounds from formamide under proton irradiation

Layperson's writeup:-

Life's building blocks created in space-like conditions

[Paprika]

“But the catch is that the total mass of meteorite that’s coming in after the Moon-forming event is negligible,” he adds. “You can’t rely on the Late Heavy Bombardment to bring you much in terms of organics. Besides, that amount of carbon is negligible compared to what’s here on Earth already.”

Another terribly unlikely possibility.

Let us know when there's anything more.