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Imagine a molecule that can create identical copies of itself from some other molecules floating around; not by any "factory" but just by "lego mechanics". This

by arp242 3y ago

Imagine a molecule that can create identical copies of itself from some other molecules floating around; not by any "factory" but just by "lego mechanics". This is more or less what prions do. At some point a slightly different molecule appears which is better at converting the molecules, or perhaps they can convert other types of molecules for replication: the first evolutionary step. Perhaps some other mutation allows molecules to "harvest" the other molecules to replicate themselves: the first predators. Over time this becomes more complex; from singular molecules and proteins to lots of molecules and proteins. I don't know what Von Neumann "showed us", but IMHO it's not hard to imagine life starting from very simple and humble origins given the enormous timeframes involved (IMO the biggest challenge in understanding these sort of things is understanding just how long a million or 10 million years is, insofar we're even able to do that in the first place).

SkyBelow 3y ago
>This is more or less what prions do. I feel this is a bad example to use because prions only do so due to the existence of plenty of things as complex as prions. We would need an example that creates more complex structures out of simpler building blocks, not equally complex building blocks.
- arp242 3y ago
  That's fair, but it's the best example I know of to demonstrate how this could have worked, even though it's not perfect. Happy to hear of other better examples.
- akasakahakada 3y ago
  Crystal can grow itself if you put it into or let it touch a solution of its own kind. I would say solid state is more complex than fluid.
  - pfdietz 3y ago
    Crystals have very little information content, though.
    - flangola7 3y ago
      What do you mean by information content.
      - pfdietz 3y ago
        The entropy of a perfect crystal approaches zero (at absolute zero). All the positions of the atoms are completely predetermined, so there is no information stored.
        akasakahakada 3y ago
        You remind me this thing. Those non perfect crystals which are dominant in the real world can have some of the most weirdest behavior in term of quantum chemistry e.g. photo synthesis. Advanced material science is making use of those crystals to make semi-conductors and stuffs because they can just absorb sunlight and then react with other substances.
ezion 3y ago
You do know that organic chemistry will quickly degrade right? And they have no memory, correct? So you're telling me that compounds floating around self-assemble into a factory and the information necessary for the factory, including error correcting code, in a short amount of time, randomly? I don't think you've thought this through.
- arp242 3y ago
  You're approaching this from a very high-level abstract theoretical point of view; things probably were significantly simpler than you're imagining. There was no "factory" or "information" or anything like that: just basic mechanics on the molecular level. This is still how things like DNA work today, as well as prions as I mentioned before, albeit these are much more complex than earlier life of course.
- johncolanduoni 3y ago
  Perhaps you could detail how organic chemicals without exception degrade rapidly. You may want to share this groundbreaking insight with those that study PFAs, some of which have estimated environmental half-lives of over 1000 years. It's also worth noting that a lot of environmental degradation is caused by the processes of living organisms, which is obviously not an issue if life has not evolved yet.
  - AstralStorm 3y ago
    Additionally there are some theories that rudimentary cell like structures formed in clays, which could protect initial unstable molecules. Then it turned out that adding a biofilm improved the resilience of the barrier. Cell wall is a really amazing thing.
  - marcinzm 3y ago
    Even modern RNA and viruses can last for days which is frankly a lot of time. A quick Google indicates you can probably get weeks out of some RNA molecules in reasonable environments.
- AbrahamParangi 3y ago
User23 3y ago
> I don't know what Von Neumann "showed us", but IMHO it's not hard to imagine life starting from very simple and humble origins given the enormous timeframes involved It’s not hard to imagine a fire-breathing red dragon or a unicorn either. What is hard is coming up with an even remotely testable hypothesis for how non-living molecules became alive.

by arp242 3y ago

SkyBelow 3y ago

>This is more or less what prions do. I feel this is a bad example to use because prions only do so due to the existence of plenty of things as complex as prions. We would need an example that creates more complex structures out of simpler building blocks, not equally complex building blocks.

arp242 3y ago
That's fair, but it's the best example I know of to demonstrate how this could have worked, even though it's not perfect. Happy to hear of other better examples.
akasakahakada 3y ago
Crystal can grow itself if you put it into or let it touch a solution of its own kind. I would say solid state is more complex than fluid.
- pfdietz 3y ago
  Crystals have very little information content, though.
  - flangola7 3y ago
    What do you mean by information content.
    - pfdietz 3y ago
      The entropy of a perfect crystal approaches zero (at absolute zero). All the positions of the atoms are completely predetermined, so there is no information stored.
      - akasakahakada 3y ago
        You remind me this thing. Those non perfect crystals which are dominant in the real world can have some of the most weirdest behavior in term of quantum chemistry e.g. photo synthesis. Advanced material science is making use of those crystals to make semi-conductors and stuffs because they can just absorb sunlight and then react with other substances.

ezion 3y ago

You do know that organic chemistry will quickly degrade right? And they have no memory, correct? So you're telling me that compounds floating around self-assemble into a factory and the information necessary for the factory, including error correcting code, in a short amount of time, randomly? I don't think you've thought this through.

arp242 3y ago
You're approaching this from a very high-level abstract theoretical point of view; things probably were significantly simpler than you're imagining. There was no "factory" or "information" or anything like that: just basic mechanics on the molecular level. This is still how things like DNA work today, as well as prions as I mentioned before, albeit these are much more complex than earlier life of course.
johncolanduoni 3y ago
Perhaps you could detail how organic chemicals without exception degrade rapidly. You may want to share this groundbreaking insight with those that study PFAs, some of which have estimated environmental half-lives of over 1000 years. It's also worth noting that a lot of environmental degradation is caused by the processes of living organisms, which is obviously not an issue if life has not evolved yet.
- AstralStorm 3y ago
  Additionally there are some theories that rudimentary cell like structures formed in clays, which could protect initial unstable molecules. Then it turned out that adding a biofilm improved the resilience of the barrier. Cell wall is a really amazing thing.
- marcinzm 3y ago
  Even modern RNA and viruses can last for days which is frankly a lot of time. A quick Google indicates you can probably get weeks out of some RNA molecules in reasonable environments.
AbrahamParangi 3y ago

User23 3y ago

> I don't know what Von Neumann "showed us", but IMHO it's not hard to imagine life starting from very simple and humble origins given the enormous timeframes involved It’s not hard to imagine a fire-breathing red dragon or a unicorn either. What is hard is coming up with an even remotely testable hypothesis for how non-living molecules became alive.