Fermi paradox may be not paradoxical at all, when you realize that accidental self-assembly of self-replicating mechanism is unlikely, namely:
Earth, being a diversely dynamic planet, had billions of years to spare, and yet it seems that it has not been able to create an alternative to ribonucleic life. If it was easy, we would expect to see life based on many kinds of self-replicating molecules, yet all life that we see is based on a single kind -- RNA/DNA, and just a single tree of life... or so we think?
SNRL would be the effort to search for non-ribonucleic life, and function a bit like SETI, as a public-benefit non-profit, and an open publicly funded effort.
The good part -- everyone could start looking for the new kind of life pretty much wherever they are.
NOTE: self-replication in nature seem to be hard, because with all our advanced computing technologies, we struggle to make a self-replicating machine even at macroscopic scale. Think of an independent self- replicating drone? Nah, you need complex supply chains. No robots terraforming Mars.-- Mindey, May 26 2019 Hypothetical types of biochemistry https://en.wikipedi...pes_of_biochemistryRelated to the quest: People had long been pondering about the alternative types of biochemistry, but never really witnessed a replicator form in them. [Mindey, May 29 2019] Exo stuff found in mountain https://www.science...h-african-mountains [not_morrison_rm, Jun 01 2019] Elephant snowshoes Snowshoes_20for_20elephants [not_morrison_rm, Jun 02 2019] Santa Fe Institute: Origins of Life https://www.complex.../95-origins-of-lifeFor anyone interested, the Santa Fe Institute of Complexity Science is running an open and free course going into exactly this topic. Starts June 14th [zen_tom, Jun 11 2019] I think your premise ([i]f it was easy, we would expect to see life based on many kinds of self-replicating molecules) is flawed. Once one biochemistry has established itself for a million years or so, no new biochemistry has a chance.
All extant life benefits hugely from being interrelated. Lions can eat gazelles because they share the same biochemistry. Gazelles can eat grass for the same reason. Bacteria can eat dead lions, likewise. I'd be very surprised if any planet had two or more fundamentally different types of native life.-- MaxwellBuchanan, May 26 2019 // I think your premise ([i]f it was easy, we would expect to see life based on many kinds of self-replicating molecules) is flawed.
Thought of that. Thing is, with that vast amount of time, and diversity of environments and materials, and potential niches,.. if it was easy, you would still see *something* (e.g., some principally different basic replication mechanisms that barely evolved, yet continue to manifest in some environments). Being different can even be helpful, because you might be not competing for the same kind of stuff.-- Mindey, May 26 2019 I have got a funny feeling life is just a higher recursive amalgamation of the underlying energy flows. Our corner has set flows, with our produced materials hence RNA/ DNA is the overall collective production.
This does not mean we can't use our mind to circumvent nature and travel to another unique energy place with non RNA/DNA underlying prototyping energies.
So , yes, on [Maxwell]'s side about our section of the universal energy tree.-- wjt, May 26 2019 > Once one biochemistry has established itself for a million years or so, no new biochemistry has a chance.
But look at the crystals, they are some form of multiplication of pattern. While they don't mutate to more complex stuff, yet they don't seem to be pushed out by competition. So, suppose there is a crystal that does mutate to something a little replicating and more complex. Would it be expected to be pushed out by existing life? I think not, it would be there, just manifesting around like a more complex and dynamic form of fun matter. Yet, we don't see that. Why? Well, as said, I think because self- replication is hard. The other possibility is that superior form of replicator out-competes the previous one, which may be true (e.g., future computers may obsolete biology), however, we had not seen that happen in the past and with respect to self-assembled replicators. For as long as we know, there was just RNA.
> I have got a funny feeling life is just a higher recursive amalgamation of the underlying energy flows.
It very much feels like it. I tend to think of life as recursive replication, that's opposing the noise or entropy, much like nuclear fusion opposes gravity... Life may be the accretion disk of information around some entropy field, and these amalgamations may be like proto-planets orbiting the source of entropy field.
SIDE NOTE: IF (self-assembly of self-replicating molecule is inherently hard) AND (we witness Fermi paradox) THEN (that rules out panspermia).-- Mindey, May 26 2019 But wait; contra [MB], supposing that the putative non- ribonucleic life started in an autotrophic form, surely that life form would derive great advantage from the fact that nothing could eat it. That fact alone would cause it to elbow aside the grazed grasses etc. until such a time as it evolved into its own predators. No?-- pertinax, May 26 2019 //But look at the crystals// Oddly enough, I've seen arguments that clay does what you're describing, with clay minerals seeding new environments and triggering the crystallization of more of themselves.
//surely that life form would derive great advantage from the fact that nothing could eat it// Yes, that's a fair point.-- MaxwellBuchanan, May 26 2019 This/our energy environment doesn't support or allow the crystals freedom enough to cycle onwards to complexity. Although the level the clay crystals have reached is still part of our formation and complexity.
Out there there maybe a system with the right astrology, I mean astro-physical pattern that produces agamogenic Golems. Or if sexual, some way of getting their little rocks off.-- wjt, May 26 2019 [Ian Tindale], so you now decoupled life as information process from its substrate. I have no objections to that. But what would then follow from it?-- Mindey, May 26 2019 // human language being a form of an information-based life //
It has been shown (through creation of simple computer viruses), that self-replication in our virtual universes (like language) may be easy. It's not the point. The point is, that it may be a hard thing to arise spontaneously given the existing laws of physics of our universe. We've got just one example where self-replicator has spontaneously arisen, namely, RNA.-- Mindey, May 29 2019 The information always needs a substrate. Complex 'living' information won't survive on a simpler substrate.-- wjt, May 29 2019 //We've got just one example where self-replicator has spontaneously arisen, namely, RNA.// It also quite likely that there were other replicators before RNA. Either they got et by the more advanced nucleic acid-based protolife, or they evolved into it.-- MaxwellBuchanan, May 29 2019 //...and yet it seems that it has not been able to create an alternative to ribonucleic life//
With a few faith-based exceptions, everyone who knows and understands enough about the biochemistry of life on Earth is fairly comfortable with every living thing being related and having 'the same' encoding in nucleic acids... But this overarching theme doesn't go in to all the details of variation in chemistry. You presumably already know that all large organisms use DNA for their genome, while some viruses use RNA. There are also variations in the pairing state of the genome - some viruses use single-stranded DNA, for instance (the 'typical' structure is two anti-parallel molecules). But beyond this, there are also a variety of tweaks to the chemistry which some organisms have made. DNA is often methylated in a variety of different ways, depending on the organism. I don't remember any of the details, but for examples: I met a guy with a poster at a conference who worked on ... some marine microorganism... the genome of which couldn't be directly sequenced, because the chemistry of it was too different to that used in sequencing reactions. (He'd had to make do with mRNA sequencing) Viruses are in a perpetual arms race with their hosts. Some bacteriophages modify the bases in their DNA - sometimes multiple times ('hypermodification') - to protect it from the host's defences or as part of their life-cycle. Within an organism, a very large variety of individual base modifications are made at very specific sites, particularly in functional RNA molecules like transfer- and ribosomal RNA.
//We've got just one example where self-replicator has spontaneously arisen, namely, RNA.//
We don't strictly know that. We think that might be the case. And if so, there was a take-over event.
So to sum up - it really isn't that one functional data storage molecule arose, and has been used ever since in all life. The data seems very much consistent with the idea that from the initial replicators a generally well- suited molecule type was selected for, and variations on that have been evolving ever since, in niches to which they are specifically suited.
If you want 'non-ribonucleic' life, you're going to have to be more specific on what that means, because it's a pretty broad church. I wouldn't be surprised if, with a bit of poking around, I could find a paper about an organism which modifies the DNA backbone (the ribose - phosphate chain) in some minor way, either before or after synthesis. Scientists have made a number of nucleic acid variants, changing the phosphate and/or the sugar groups - such as PNA - peptide nucleic acid. (Note that I haven't claimed that they'd function as genomic material; it's an example to help you consider what you'd accept as sufficiently different.)
//Thing is, with that vast amount of time, and diversity of environments and materials, and potential niches,.. if it was easy, you would still see *something* (e.g., some principally different basic replication mechanisms that barely evolved, yet continue to manifest in some environments). Being different can even be helpful, because you might be not competing for the same kind of stuff.//
I'm not saying self-replicating molecules are 'easy', but life seems to have arisen on the Earth pretty much as soon as it was physically possible for it to work. (With a certain degree of measurement error - which is quite a long time on a human scale of course.) And once you have one replicator type almost ubiquitously present on a planet, in a certain sense it really will be competing for the same stuff - energy, and useful atoms. If you want your xeno-replicators not to be using the generally useful atoms... well, the bad news is that what's left is going to be harder to work with, and those pesky high-function life-forms may just use your energy source before you get to it. This doesn't mean it's impossible - but if it's on Earth, I think you'd expect to find a reason - why more normal life-forms just plain couldn't live in that environment.-- Loris, May 29 2019 <makes note to test Sturton for DNA>-- MaxwellBuchanan, May 29 2019 You beat me to it. Anyway, novel new non-rna stuff is to be found on any chem project that gets forgotten and ends up on a windowsill in the lab.-- not_morrison_rm, May 31 2019 I'm sure someone else must have already pointed this out?
But any new precursors to life that develops in some pond scum somewhere anytime after life first becomes reasonably prevalent on a world is liable to get gobbled up by the extant life long before it can evolve.
Just to be clear, when I say "liable to" I mean it's inevitable.
Any semi-organic compounds that can't run away are just a tasty snack for anything that's already there.
It's the main argument against a multiple genesis of life ever taking hold on a single planet & makes this idea a bit moot.-- Skewed, May 31 2019 //It's the main argument against a multiple genesis of life ever taking hold on a single planet & makes this idea a bit moot//
So in short SETI itself is in fact your best chance of finding your "Non-Ribonucleic Life".
That or close inspection (probably requiring a visit) of other planets in our own solar system perhaps?-- Skewed, May 31 2019 Is there a quantified amount or density for materials to start life?
I'm imaging a big rocky planet and the only life is where a small rich vein of materials, in one canyon, resides in complex pattern of planetary motion.-- wjt, Jun 01 2019 There is a need for new clarity over the term 'life' as the digital world displays many characteristics that fit the current descriptor.-- xenzag, Jun 01 2019 Put up a link to extraterrestrial organic matter found in South Africa, almost sure it's nothing to do non-Ribina stuff.-- not_morrison_rm, Jun 01 2019 //almost sure it's nothing to do non-Ribina stuff//
You sure about being almost sure?
From your link [morri] "we don't know what form this ancient organic matter once took"
So it could be orangeaid or a lime wedgie (both distinctly non- ribena) for all they know?-- Skewed, Jun 01 2019 I would point you to the mysterious origins of umbongo but...
While I'm here, I was pondering if Kurosawa stint in San Francisco, in a cold cuts store owned by an uncle ,gave him his lifelong penchant for bacon. It's quite sure the original title was Rasher-mon.
And kids, that how the elephant got its snowshoes.-- not_morrison_rm, Jun 01 2019 Hey, guys, if you've got drugs it's nice to share them around.-- MaxwellBuchanan, Jun 01 2019 Hmm, the pachydermal ones have their own post know - link. Like Oppenhomer ©NMRM* after the Trinity test, I suspect that most yeti remains will be now found on the soles of elephants.
*the happy go-lucky joe who directs a nuke bomb factory, with his catch phrase "Hmmm, Strontium".
Ok, I'll stop hogging HB.-- not_morrison_rm, Jun 02 2019 //you've got drugs it's nice to share them around//
Now that's how dosage gets out of control.-- wjt, Jun 02 2019 The Santa Fe institute is running a (free, open) course on this exact theme - enrolment open till June 14th - see link.-- zen_tom, Jun 11 2019 [zen_tom], good discovery. [enrolled]-- Mindey, Jun 11 2019 random, halfbakery