Prebiotic Generation of RNA Polymers

[JeffKos]

Hi,

I placed this question in the "Evolution, Morphology and Exobiology" sub-forum, and didn't get many responses, so i thought I try my luck here.

I’m curious about how biological processes arose from pre-biological ones (i.e., how life arose).  The “RNA World Hypothesis” suggests that RNA-like molecules are a good candidate.

However, in order to entertain this hypothesis, one has to presume there was either a natural abundance of nucleotide monomers floating around – in an environment that encouraged them to form into polymers… or, there was some natural process that was essentially producing RNA chains, of various lengths and consisting of various nucleotides.

Question:  Are we aware of any natural (non-biological) environments on earth today, in which nucleotide monomers (or oligomers) are produced?

Or, for that matter, ANY monomer – polymer families that are naturally occurring - from which RNA might have slowly evolved / emerged?

And as long as I’m on the topic, what about sugar polymers?  Are there any examples today of the non-biological creation of sugar monomers or oligomers?

Thanks in advance,

JeffKos

[Area54]

18 hours ago, JeffKos said:

And as long as I’m on the topic, what about sugar polymers?  Are there any examples today of the non-biological creation of sugar monomers or oligomers?

Since I provided an affirmative answer to this question on your previous thread, but you have chosen to ignore that response I see little point in making the effort to answer it again, or to address any of your other questions. Good luck with your search.

[Moontanman]

18 hours ago, JeffKos said:

Hi,

I placed this question in the "Evolution, Morphology and Exobiology" sub-forum, and didn't get many responses, so i thought I try my luck here.

I’m curious about how biological processes arose from pre-biological ones (i.e., how life arose).  The “RNA World Hypothesis” suggests that RNA-like molecules are a good candidate.

 

However, in order to entertain this hypothesis, one has to presume there was either a natural abundance of nucleotide monomers floating around – in an environment that encouraged them to form into polymers… or, there was some natural process that was essentially producing RNA chains, of various lengths and consisting of various nucleotides.

 

 

Question:  Are we aware of any natural (non-biological) environments on earth today, in which nucleotide monomers (or oligomers) are produced?

 

 

Or, for that matter, ANY monomer – polymer families that are naturally occurring - from which RNA might have slowly evolved / emerged?

And as long as I’m on the topic, what about sugar polymers?  Are there any examples today of the non-biological creation of sugar monomers or oligomers?

 

Thanks in advance,

JeffKos

I answered you as well, I guess googling the clay assertion was a bit much to expect. I should have provided citations. I can provide you with two one hour videos by Jack Szostak but this one is shorter and gives you the idea and possibly some places to start searching. 

 

[JeffKos]

Area54: 

Thanks for your reply.

Sorry for the misunderstanding. 

Not sure what makes you think I was "ignoring" your response.  I was just hoping to get a few more responses in this specific sub-forum.

Yes, I'm aware that sugars have been identified on some asteroids and comets, as well as deep space.  However, as my question alludes, I'm looking for evidence for processes occurring here on earth - that might have helped feed the basic pre-biotic processes.

Thanks again...

JeffKos

 

Moontanman:

Thanks for the reply; on both sub-forums.

Yes, I'm aware of the "clay" hypothesis - as a means of acting as a template for catalyzing chains of monomers.

However, I'm interested in finding pre-biotic sources of the monomers themselves.  The "clay" theory presupposes the ribo-nucleotides were already there.  I'd like to know where they might have come from.

Thanks again,

JeffKos

[Area54]

7 hours ago, JeffKos said:

Area54: 

Thanks for your reply.

Sorry for the misunderstanding.

No problem.

On 09/09/2017 at 2:11 AM, JeffKos said:

Question:  Are we aware of any natural (non-biological) environments on earth today, in which nucleotide monomers (or oligomers) are produced?

I believe you are asking the wrong question, for two reasons.

Firstly, the vast majority of Earth environments (surface and upper crust) that exist today are substantially different at the time prebiotic material was likely to have been produced. A more measured question would be "Are we aware of any natural (non-biological) environments on the primeval Earth in which nucleotides could have been produced?"

Secondly, as I pointed out in my original reply, restricting the origin of prebiotic molecules to the Earth is an uneccessary and unwarranted restriction. An even better question would have been, for the sugars, "Are we aware of any natural (non-biological) environments on the primeval Earth in which sugars could have been produced, or of any mechansim by which they could be delivered from space?" The answer, as I gave, is yes.

In regard to the sugars, what do you find unsatisfactory about an extraterrestrial origin?

Note: In the original thread someone else suggested, I think, that the Miller-Urey experiment yielded nucleotides. I'm pretty sure it generated gunk and several amino acids, but no nucleotides. I stand ready to be corrected on that point.

[JeffKos]

Area54,

Thanks again for your reply.  Here's my two cents to your two cents.

You say >> I believe you are asking the wrong question <<

Interesting choice of words:  I believe there are great questions, better questions and good questions - but I've never thought about what a "wrong" question is.  Hmmm.  (Are there "bad" questions as well???)

You say >>

On 9/14/2017 at 2:07 AM, Area54 said:

A more measured question would be "Are we aware of any natural (non-biological) environments on the primeval Earth in which nucleotides could have been produced?"

However, if I understand you, you suggest there IS no answer to this question, because...

On 9/14/2017 at 2:07 AM, Area54 said:

Firstly, the vast majority of Earth environments (surface and upper crust) that exist today are substantially different at the time prebiotic material was likely to have been produced.

... inferring that the environment of the primeval earth, which would likely be vastly different than today's,  is not available for research.  (And maybe, not necessarily a more measured question?)

My personal hunch about this is, yes, the primeval world was so un-imaginably different than today's, and may have in fact been exuding / producing massive quantities of nucleotide precursors.  In which case, there would be no need for extra-terrestrial assistance.  In which case, the RNA world theory gets further support.

However, before I naively presume that the earth was somehow naturally (and pre-biotically) producing scads of RNA monomers, I thought I'd ask this forum if anybody was aware of any evidence on TODAY'S earth, where this was in fact actually happening.  To date, I've found no information that contends that it is occurring.  (Which doesn't necessarily prove that it isn't though).

Regarding your comment about extra-terrestrial sugars:  What bothers me about the idea of pre-biotic "seeds" arriving on earth via asteroids and meteors, is that all of these vehicles had to pass through the atmosphere first, and be subjected to horrendous temperatures.  Small meteorites would probably completely vaporize.  Only very large ones would make to the earth's surface with their interiors not scorched and um, thermally readjusted.  But if they made it this far, they'd next have to contend with contacting either liquid or solid surfaces, at hyper-sonic speeds - which also would not likely be hospitable to the organic chemicals that survived re-entry.

And I could be totally wrong about this.  Maybe there were in fact zillions of Goldilocks-sized meteorites falling to earth, and maybe the pre-biotic atmosphere wasn't that inhospitable, yadda yadda.  But ultimately, IMHO, it would make for a simpler story, if there was an identified mechanism in place on earth, or one that could be fairly easily imagined.

My hope is that, should we ever make it to Titan and Enceladus, we'll discover geo-thermal chemistry going on that will make our scientific eyes pop out of our simian heads.  Chemistry that we'll be able to infer very-likely happened on earth as well.  My hope.

Thanks again for your reply.

Jeff