h a l f b a k e r yThis ain't rocket surgery.
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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.
Hypothetical types of biochemistry
https://en.wikipedi...pes_of_biochemistry
Related 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-life
For 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]
[link]
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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. |
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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. |
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// 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. |
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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. |
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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. |
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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. |
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So , yes, on [Maxwell]'s side about our section of the universal energy tree. |
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> Once one biochemistry has established itself for a million years or so,
no new biochemistry has a chance. |
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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. |
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> I have got a funny feeling life is just a higher recursive amalgamation
of the underlying energy flows. |
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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. |
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SIDE NOTE: IF (self-assembly of self-replicating molecule is
inherently hard) AND (we witness Fermi paradox) THEN (that rules out
panspermia). |
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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? |
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//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. |
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//surely that life form would derive great advantage from the
fact that nothing could eat it// Yes, that's a fair point. |
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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. |
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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. |
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[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? |
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// human language being a form of an information-based life // |
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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. |
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The information always needs a substrate. Complex 'living' information won't survive on a simpler substrate. |
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//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. |
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//...and yet it seems that it has not been able to create
an alternative to ribonucleic life// |
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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. |
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//We've got just one example where self-replicator has
spontaneously arisen, namely, RNA.// |
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We don't strictly know that. We think that might be the
case. And if so, there was a take-over event. |
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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. |
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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.) |
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//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.// |
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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. |
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<makes note to test Sturton for DNA> |
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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. |
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I'm sure someone else must have already pointed this out? |
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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. |
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Just to be clear, when I say "liable to" I mean it's inevitable. |
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Any semi-organic compounds that can't run away are just a
tasty snack for anything that's already there. |
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It's the main argument against a multiple genesis of life
ever taking hold on a single planet & makes this idea a bit
moot. |
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//It's the main argument against a multiple genesis of life
ever taking hold on a single planet & makes this idea a bit
moot// |
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So in short SETI itself is in fact your best chance of finding
your "Non-Ribonucleic Life". |
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That or close inspection (probably requiring a visit) of other
planets in our own solar
system perhaps? |
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Is there a quantified amount or density for materials to start life? |
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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. |
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There is a need for new clarity over the term 'life'
as the digital world displays many characteristics
that fit the current descriptor. |
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Put up a link to extraterrestrial organic matter
found in South Africa, almost sure it's nothing
to do non-Ribina stuff. |
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//almost sure it's nothing to do non-Ribina stuff// |
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You sure about being almost sure? |
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From your link [morri] "we don't know what form this ancient
organic matter once took" |
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So it could be orangeaid or a lime wedgie (both distinctly non-
ribena) for all they know? |
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I would point you to the mysterious origins of
umbongo but... |
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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. |
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And kids, that how the elephant got its
snowshoes. |
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Hey, guys, if you've got drugs it's nice to share them around. |
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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. |
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*the happy go-lucky joe who directs a nuke bomb factory, with his catch phrase "Hmmm, Strontium". |
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Ok, I'll stop hogging HB. |
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//you've got drugs it's nice to share them around// |
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Now that's how dosage gets out of control. |
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The Santa Fe institute is running a (free, open) course on
this exact theme - enrolment open till June 14th - see link. |
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[zen_tom], good discovery. [enrolled] |
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