Re: OoL – out at first base?

On 10/12/2024 8:57 am, erik simpson wrote:

On 12/9/24 2:05 AM, MarkE wrote:

On 9/12/2024 5:20 pm, erik simpson wrote:

On 12/8/24 9:54 PM, MarkE wrote:

We need prebiotic formation and supply of nucleotides for RNA world, and other models at some stage. The scope of the problem of the supply of these precursors is prone to underestimation.
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Nucleotides are chemically challenging in terms of the prebiotic synthesis and assembly of their three constituents of nitrogenous base, sugar and phosphate group.
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Harder again are the requirements for supply of these building blocks. You need (eventually) all canonical bases in sufficient concentration, purity, chirality, activation, distribution, location, etc.
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But the greatest problem I think is this: time. How long must you maintain the supply described above in order to assemble a self-replicating RNA strand? And even if you managed that, how much more time is needed before reaching a protocell capable of self-synthesising nucleotides? One million years? One hundred million years?
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A hypothised little warm pond with wetting/drying cycles (say) must provide a far-from-equilibrium system...for a million years...or hundreds of millions of years. You can’t pause the process, because any developing polymers will fall apart and reset the clock.
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What are the chances of that kind of geological and environmental stability and continuity?
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Therefore, the formation of an autonomous protocell naturalistically has vanishingly small probability.
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The LUCA (last universal common ancestor) lived about 200 My after the formation of the moon.  There's a very outside chance it lived of Mars. That would make the proximity of the moon's formation a little easier, but surviving the launch from Mars and months-long trip to earth isn't very likely.
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The first life probably in something like a "deep smoker" with lots clay available.  Clay is a fine surface to catalize organic compounds.
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This makes the problem of time worse. If the first protocell capable of self-synthesising nucleotides developed this way, you need a "deep smoker" (or localised group) operating steadily for millions of years.
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Also, you no longer have wetting and drying cycles, which seem indispensable to support concentration of reactants, polymerisation, etc.
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No you don't. The generation time for microbes in on the order of hours.   Self-catalyzing time for a strand of RNA is probably on the order of minutes.  A black smoker need only be present for few years, and the early earth had a much hotter interior means that there were at least millions of them.  As SJ Gould remarked "life may be as common as quartz". Indeed.  All you need is hot water and a thermal or chemical gradient and you're good to go.
 

"All you need is hot water and a thermal or chemical gradient and you're good to go."
We have a very different understanding of what is involved in the formation of life. I'm with these leading OoL researchers (Damer and Deamer):
“[OoL research has] been mainly focused on individual solution chemistry experiments where they want to show polymerization over here, or they want to show metabolism over here, and Dave and I believe that it's time for the field to go from incremental progress to substantial progress. So, these are the four points we've come up with to make substantial progress in the origin of life, and the first one is to employ something called system chemistry, having sufficient complexity so instead of one experiment say about proteins, now you have an experiment about the encapsulation of proteins for example, and informational molecules built from nucleotides in an environment that would say be like an analog of the early Earth, build a complex experiment. Something we're calling sufficient complexity, and all of these experiments have to move the reactions away from equilibrium. And what do we mean by that? Well, in in your high school chemistry experiments, something starts foaming something changes color and then the experiment winds down and stops. Well, life didn't get started that way. Life got started by a continuous run-up of complexity and building upon in a sense nature as a ratchet. So we have to figure out how to build experiments that move will move away from equilibrium...”
“You can't sit in a laboratory just using glassware. You have to go to the field. You have to go to hot springs, you have to go to […] Iceland and come check and sit down and see what the natural environment is like, rather than being in the ethereal world of pure reactants and things like that...”
Source: A new model for the origin of life: A new model for the origin of life: Coupled phases and combinatorial selection in fluctuating hydrothermal pools. https://youtu.be/nk_R55O24t4?feature=shared