Progress in origin of life research - RNA world

[shunyadragon]

There is no argument by weblink. Make the appropriate quotations.

I previously cited parts from the articles that were relevant.

[shunyadragon]

Source: http://www.geochemicaltransactions.com/content/10/1/9

Reduction of nitrogen compounds in oceanic basement and its implications for HCN formation and abiotic organic synthesis

Nils G Holm* and Anna Neubeck



Hydrogen cyanide is an excellent organic reagent and is central to most of the reaction pathways leading to abiotic formation of simple organic compounds containing nitrogen, such as amino acids, purines and pyrimidines. Reduced carbon and nitrogen precursor compounds for the synthesis of HCN may be formed under off-axis hydrothermal conditions in oceanic lithosphere in the presence of native Fe and Ni and are adsorbed on authigenic layer silicates and zeolites. The native metals as well as the molecular hydrogen reducing CO2 to CO/CH4 and NO3-/NO2- to NH3/NH4+ are a result of serpentinization of mafic rocks. Oceanic plates are conveyor belts of reduced carbon and nitrogen compounds from the off-axis hydrothermal environments to the subduction zones, where compaction, dehydration, desiccation and diagenetic reactions affect the organic precursors. CO/CH4 and NH3/NH4+ in fluids distilled out of layer silicates and zeolites in the subducting plate at an early stage of subduction will react upon heating and form HCN, which is then available for further organic reactions to, for instance, carbohydrates, nucleosides or even nucleotides, under alkaline conditions in hydrated mantle rocks of the overriding plate. Convergent margins in the initial phase of subduction must, therefore, be considered the most potent sites for prebiotic reactions on Earth. This means that origin of life processes are, perhaps, only possible on planets where some kind of plate tectonics occur.

© Copyright Original Source

http://www.geochemicaltransactions.com/content/10/1/9

Again . . .

[shunyadragon]

Narrowness is hardly relevant: that scientists are still exploring varied possibilities for the environment indicates that it is not established that ocean regions were the site of abiogenesis.

Again why do you have a problem with this?!?!?!?! You do not know the motivation of the scientists involve. Again it is perfectly normal science to explore all possibilities in their research.

[Paprika]

Well I explained why it was important in my last post. Go back and read it.

You really can't read, can you? Go back and try again.

I was simply making the easy point that natural OOL experiments can be traced back a few hundred years to the downfall of vitalism.

The synthesis of urea was not OOL science. Stop trying to defend your stupid point that urea had anything to do with OOL science.

But you did say that you might tell me.

Looks like you don't even know what 'might' means.

It looks as if you have no good hypothesis and no experiments.

So you say, but that's hardly irrelevant to the topic. But you choose to focus on it because there's no other way for you to counterattack.

On the other hand, Christians and non Christians who think that natural processes may have given rise to life, do have a solid hypothetical basis which allows them to experiment and test various ideas

Indeed, the faith is rather remarkable.

So you have already written. But given that you think very little progress has been made since Urey-Miller, do you think that U-M offered anything like this understanding in their experiments:-

http://www.cell.com/abstract/S0092-8674(12)01438-9

I have no desire to entertain any of your elephant-hurling, especially when I have not denied that progress has been made.

Read the paper yourself, and make your own summary here, and I might humour you.

As with shunya, I have no wish to deal with your adolescent argument by hurling weblinks. Come back when you have something better.

[Paprika]

I previously cited parts from the articles that were relevant.

You made one correct quote, and large chunks that you wrongly attributed to it, and yet have not retracted it.

Hydrogen cyanide is...

What on earth is this supposed to establish? Though convergent margins may be the "most potent sites" or where life mostly likely started it hardly implies that life actually starting there is likely at all.

[Paprika]

Again why do you have a problem with this?!?!?!?! You do not know the motivation of the scientists involve. Again it is perfectly normal science to explore all possibilities in their research.

It is simple to deduce from their research that they are exploring different environments for abiogenesis. Hence the ocean regions are unlikely to be the established case as you paint them to be.

[shunyadragon]

It is simple to deduce from their research that they are exploring different environments for abiogenesis. Hence the ocean regions are unlikely to be the established case as you paint them to be.

Unsubstantiated assertion. Please cite references to support this. You are assuming the motive for research without a basis in how scientists determine what they research.

References please, especially a reference that the ocean regions, particularly the mid-ocean ridge are in any way unlikely for abiogenesis.

[shunyadragon]

You made one correct quote, and large chunks that you wrongly attributed to it, and yet have not retracted it.

Nothing at all to retract. If I made a mistake in the astrobiology references I will check it out. All the astrobiology reference I may have cited the first source. All the astrobiology references refer to research papers as first sources.

What on earth is this supposed to establish? Though convergent margins may be the "most potent sites" or where life mostly likely started it hardly implies that life actually starting there is likely at all.

The articles I cited describe the mid-ocean ridge environments as suitable environments for abiogenesis. The above is a bit confusing.

Convergent margins are subduction zones where ocean plates meet continental plates, not mid-ocean ridges?' You need to review you science knowledge that you frog hair picking.

Basic knowledge science and geology is important before you nitpick and criticize.

What are your academic qualifications in geology, chemistry, and the biology of abiogenesis.

[Paprika]

Nothing at all to retract.

Everything here to retract.

The above is a bit confusing.

More like it blows apart your entire case.

Convergent margins are subduction zones where ocean plates meet continental plates, not mid-ocean ridges?' You need to review you science knowledge that you frog hair picking.

Dumbass, I'm quoting the article you cited.

Source: http://www.geochemicaltransactions.com/content/10/1/9

Convergent margins in the initial phase of subduction must, therefore, be considered the most potent sites for prebiotic reactions on Earth.

© Copyright Original Source

Basic knowledge science and geology is important before you nitpick and criticize.

What are your academic qualifications in geology, chemistry, and the biology of abiogenesis.

And now you want to play the citation game to disqualify? When you can't even attribute quotes correctly? When you can't even recognise that I'm quoting from a source you first introduced?


Pathetic.

[Paprika]

Unsubstantiated assertion. Please cite references to support this. You are assuming the motive for research without a basis in how scientists determine what they research.

Why would so much research be conducted if the site of abiogenesis is established? The implication is very clear.

References please, especially a reference that the ocean regions, particularly the mid-ocean ridge are in any way unlikely for abiogenesis.

Since you don't clarify which scenario I'll try to be as general:

This paper critically evaluates various RNA world scenarios. I quote some relevant points:

4.1. Problem 1: the primitive formation of RNA proceeds only under specific conditions

The RNA world hypothesis has been experimentally verified on the basis of different principles. However, further critiques from different viewpoints are also valuable for improving the studies on origin of life as well as the RNA world hypothesis.

Data from simulation experiments for the chemical evolution of RNA indicted that the formation pathways of RNA polymers are through activated nucleotide monomers and inorganic materials (Tables 2and 3). However, some questions remain. First, it is difficult to determine whether the initial conditions are comparable to primitive earth environments. Second, it is not yet clear whether the efficiency of each chemical evolution step is sufficient for usage in later steps, such as the formation of long oligonucleotides. For instance, the yield of ribose formation is considered too low for it to be a source of RNA components [35] and [36]. In addition, the formation of nucleotides from their components seems to be difficult except for under very limited conditions; these investigations were only carried out in very early studies. Thus, the experimental conditions are regarded as plausible primitive earth conditions. It is difficult to determine the exact amount or concentration of ribose necessary for the formation of nucleosides; this evaluation has not yet been carried out. Similar questions can be asked for proteins. Verification of the initial conditions, where the RNA polymers could have formed, would be important for the evaluation of the accumulation of RNA or RNA-like molecules.

Those proposing ocean scenarios (or most scenarios in general) cannot verify the initial conditions, which was necessary in the experiments they report. Now without such empirical proof, all we have to fall on is the very well known difficulties and hence unlikely reactions involved in forming RNA, especially macromolecule formation.

The accumulation of RNA is determined by both the rate of its formation and its degradation, and the flow rate of inflow and outflow to the system (Fig. 7) [28] and [83]. This is important since a life-like system emerged in a thermodynamically open system. However, it is noted that the importance of the relative rates of the formation and degradation is not appropriately studied. For instance, if the relative rate between formation and degradation is similar between the two different systems, the accumulation behavior as a function of time becomes analogous between these systems.

An experimental setup that simulates an open system of RNA chemical evolution is currently difficult. Mathematical simulations cannot be properly performed, since kinetic data are not sufficiently available for the formation and degradation of activated nucleotide monomers and product oligonucleotides. Thus, the discussion about the assumption that under the primitive earth conditions, proteins are more likely to accumulate compared to the RNA molecules is not meaningful even if one attempts to assume whether RNA or protein is suitable as the first material for the life-like system based on the stabilities of the molecules.

So much is still unknown, as above.

4.3. Problem 3: In vitro selection for functional RNA requires molecular biology techniques. were there such effective selection mechanisms for the RNA-based life-like system?

In vitro selection of RNA involves analogous processes to the real evolution of organisms. However, this method consists of totally artificial materials and procedures such as a DNA synthesizer, in vitro transcription of DNA to RNA, affinity column chromatography, which binds target RNA, and reverse-transcription PCR ( Fig. 5). The question is whether such an evolutionary system was present under the primitive earth environment. Although this should be experimentally verified, such attempts have not been successful.

In sum, to the best of our knowledge there is no natural mechanism for sorting through useless and [life-]functional RNA. Without such a mechanism, the rise of life would be quite unlikely.

And so on and so forth; you can read the rest at the link.

Now, do note that I don't plan to give any more references unless a) you can provide any reference that supports your own position - that the ocean regions, particularly the mid-ocean ridge are in any way likely for abiogenesis, which you haven't up to this point and b) you can refute what this paper has brought up.

[shunyadragon]

Everything here to retract.


More like it blows apart your entire case.


Dumbass, I'm quoting the article you cited.

Source: http://www.geochemicaltransactions.com/content/10/1/9

Convergent margins in the initial phase of subduction must, therefore, be considered the most potent sites for prebiotic reactions on Earth.

© Copyright Original Source

And now you want to play the citation game to disqualify? When you can't even attribute quotes correctly? When you can't even recognise that I'm quoting from a source you first introduced?


Pathetic.

What are your qualifications for making your assertions?

[Paprika]

What are your qualifications for making your assertions?

I can actually quote and make arguments from papers, unlike yourself.

Which is why you're playing the qualifications game, trying to disqualify because you can't win by reasonable argument. Utterly pathetic.

[shunyadragon]

It is simple to deduce from their research that they are exploring different environments for abiogenesis. Hence the ocean regions are unlikely to be the established case as you paint them to be.

Again and again and again. I need sources not opinions.

[shunyadragon]

I can actually quote and make arguments from papers, unlike yourself.

Which is why you're playing the qualifications game, trying to disqualify because you can't win by reasonable argument. Utterly pathetic.

No you have not supported your assertions, nor have you provided you qualifications to make ridiculous assertions.

[Paprika]

No you have not supported your assertions

You lie.

nor have you provided you qualifications to make ridiculous assertions.

I don't need to provide qualifications to make statements supported by scientific literature.

But go on, keep trying to disqualify. Expose your desperation.