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What appear to be biochemical processes may be a natural feature of geology

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Re: What appear to be biochemical processes may be a natural feature of geology

#111

Post by IAmBroom »

pocksuppet wrote: post #86
adrian_b wrote: post #27

Earlier quoted context omitted.

I agree. It seems that the choice between left-handed and right-handed amino-acids was random. However, it is unlikely that other kinds of life forms could use both kinds indiscriminately, because mixing them creates difficulties in the assembling of polymers. So it is likely that amino-acids produced by some extra-terrestrial life form would also be predominantly of only one orientation, but it could happen to be th…

It could also be that other forms of life produce both forms, but selectively use one.

Wouldn't that require a constant filter, to ensure that L-processes never use R-amino compounds? Seems almost like a Maxwell's Demon would be required in every cell...

Re: What appear to be biochemical processes may be a natural feature of geology

#112

Post by IAmBroom »

trentnix wrote: post #46

Genesis 2:7 (NIV) Then the Lord God formed a man from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being.

Yeah... so pretty much exactly, precisely, 100.000% the opposite of that.

Re: What appear to be biochemical processes may be a natural feature of geology

#113

Post by pocksuppet »

IAmBroom wrote: post #111
pocksuppet wrote: post #86

Earlier quoted context omitted.

It could also be that other forms of life produce both forms, but selectively use one.

Wouldn't that require a constant filter, to ensure that L-processes never use R-amino compounds? Seems almost like a Maxwell's Demon would be required in every cell...

They just can't use those compounds. Many medications have L and R forms of which only one is active. Right-methamphetamine is, well, methamphetamine, but left-methamphetamine is a nasal decongestant. Which is to say that the unwanted variation of a compound can be harmless.

Just about every molecule in every cell is already a maxwell's demon. They only fit together in specific ways.

Re: What appear to be biochemical processes may be a natural feature of geology

#114

Post by eks391 »

nilkn wrote: post #103
eks391 wrote: post #101

Earlier quoted context omitted.

I almost agreed with your comment, but then I remembered there are countless planets with conditions unsuitable for life (as we know life). We have found a couple planets that are optimisticly closer to Earth conditions, but very few, and there is usually some characteristic that makes it a stretch still. With that said, if Earth was compared to a super computer, the initial conditions and perturbations (weights and…

I've actually thought about this. My personal interpretation (which I admit is absolutely a bit playful, but I also find it very fulfilling) is that gravity acts like a resource allocator. It clumps matter together into stars, planets, etc., forcing it to interact, while keeping those objects far enough apart that they generally can run independently of each other for very long periods of time. If you allow me to exe…

You had me at

> gravity is just launching countless trillions of parallel instances of the same computation, with nearly all possible initial starting conditions

Great take and conclusion, no issue with the playful language here. It makes sense that, entropy being a required output with time, and 'infinite' near isolated cases would find just about every way to create that entropy, to include the efficiency at creating it (life, as you said).

Lovely take. Earth is a supercomputer. And to play on sibling responses to your first comment, this supercomputer is solving the answer to life, the universe, and everything. The answer is entropy though, not 42

Re: What appear to be biochemical processes may be a natural feature of geology

#115

Post by mjanx123 »

nilkn wrote: post #41

It's been speculated for at least a decade now that geochemistry spawned biochemistry and life as we know it. This appears to be the latest instance of this pattern. One of the most notable examples is geothermal processes simply creating calm energy gradients that are stable for billions of years (e.g., underwater alkaline vents), which can then essentially "manufacture" organic compounds, which naturally assemble i…

> I like to think of the Earth as a supercomputer running a vast self-interactive chemical computation of unfathomable scale for an unfathomably long amount of time.

42

Re: What appear to be biochemical processes may be a natural feature of geology

#116

Post by myrmidon »

trentnix wrote: post #46

Genesis 2:7 (NIV) Then the Lord God formed a man from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being.

It would have been very easy for older religions to present strong evidence for divinity: just have some explicit, non-trivial facts in the holy book that were unknown to humankind when those books were written, like earth-moon/sun distance, speed of light, etc.

Complete absence of anything like that is a pretty strong indicator by itself...

Re: What appear to be biochemical processes may be a natural feature of geology

#117

Post by asdff »

adrian_b wrote: post #83
cyberax wrote: post #47

Earlier quoted context omitted.

> The fact that on Earth the living beings eventually used ATP and RNA appears to have been determined in great part by chance, while the use of amino acids seems to have been much more deterministic. It looks like on Earth the RNA was the initial replicant. RNA can be folded into complex shapes and can have catalytic properties in itself. Ribosomes that assemble proteins have RNA at the active site with proteins onl…

RNA was indeed the initial replicant, i.e. the first molecule that contained an arbitrary sequence of blocks and which could be used as a template to generate copies at itself. However, such a replicant could appear only after a life form with metabolism already existed. For replicating RNA, there must exist a complex system that extracts energy from the environment and uses that energy to synthesize nucleotides like…

Some caveats with this theory is that these non ribosomal peptides are synthesized by an enzyme that itself is encoded in DNA.

But RNA alone is sufficient to template off itself and create new copies. It can fold into catalytic forms akin to folded proteins. It can even spontaneously generate into chains from the constituent monomers under certain assumed early earth conditions (1). There is a lot of literature behind this formation under various conditions. A lot of guestimates on what these conditions might translate to experimentally, but the general trend is that this seems to be possible under early earth conditions.

1. https://pubs.acs.org/doi/full/10.1021/acscentsci.5c00488

What is left is determining how the consitutent nucleotides might have formed. People have ideas on this though. This review is a bit old now but on topic at least: https://pmc.ncbi.nlm.nih.gov/articles/PMC6316623/#sec4-life-...

Re: What appear to be biochemical processes may be a natural feature of geology

#118

Post by mjanx123 »

adrian_b wrote: post #88
cyberax wrote: post #84

Earlier quoted context omitted.

Sugars are just chains of hydrocarbons with alcohol groups, they are probably going to be ubiquitous. ATP is useful because the phosphate groups make a stable bond that nevertheless can be hydrolyzed, releasing a lot of energy. But the adenosine "backbone" of the ATP is more-or-less arbitrary. Other forms of life can use something different. Or they might use the phosphorus bonds themselves where terrestrial life use…

I also do not believe that our RNA and complex amino acids are likely to be universal. On the other hand, the simple amino acids are known to be universal, both from chemical analyses of celestial bodies and from abiotic syntheses in laboratories. In theory, sugars can be produced abiotically by the polymerization of formaldehyde. However, sugars are not very stable chemically and suitable catalysts for formaldehyde…

- cells appear very soon after the hadean Earth - meteorites contain life building blocks

These suggest that the life chemistry evolved in the proto solar cloud (and exploring the conditions in there would yield how that happened) and the life on Earth evolved from the already complex stuff that fell on it after the hadean phase.

Re: What appear to be biochemical processes may be a natural feature of geology

#119

Post by mjanx123 »

vanderZwan wrote: post #78
foota wrote: post #76

What if life was born under the surface?

Well, as far as I understand it's pretty much a given that it happened underwater or underground, to protect against cosmic radiation and other harsh conditions averse to lifeg so that's not really a "what if" unless you meant something else than I think you did. Mind you, "soil" as we know it did not exist before life was there to create it. Geology as it exists on Earth does not exist on lifeless planets.

Water is also averse to emergence of life chemistry, despite the mature life depending on it, it hydrolyzes and damages the fragile structures. It is the same situation as with oxygen in principle.

Re: What appear to be biochemical processes may be a natural feature of geology

#120

Post by gamblor956 »

stymaar wrote: post #58
gamblor956 wrote: post #36

Earlier quoted context omitted.

You might be thinking of something else. UHT has a very long shelf life compared to other forms of liquid milk.

Compared to other forms forms of liquid milk indeed, but it has a rather short shelf life compared to most sterile food. (Imagine if canned meat or fish had the same shelf life than UHT milk…)

Meat and fish subjected to the same processes as UHT milk (i.e., brief explosure to ultra-high temperatures) only lasts a few days, so UHT milk lasts way longer than the comparables.
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