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It also seems to assume that there is only one "path" to "observer" status. For example, could there be an alternative to Eukaryote cells that would allow equi

by enkid 6y ago

It also seems to assume that there is only one "path" to "observer" status. For example, could there be an alternative to Eukaryote cells that would allow equivalent cognition to our own? We don't know because we only have one instance of "observers" coming around.

jjoonathan 6y ago
Sure, all of this is speculative, but the eukaryotic jump is notorious for getting casually dismissed on account of being misunderstood. I think it's one of the better candidates for a filter, so let me advocate it for a second and make sure that if you still want to dismiss it's not due to oversight. The problem has nothing to do with having a nucleus. That's the solution. As you note, it's possible to imagine other solutions. The problem is dealing with gigabytes of genetic data instead of mere megabytes. Typically one would use units of base pairs, but in the context of talking about potential alternative forms of life I'd argue that units of information are more appropriate. In any case, the "easy" strategies suffer from a severe dead end that prevents them from going beyond a few megabytes. Lots of things go wrong at that limit, and while other forms of life would encounter those obstacles in slightly different places, the problem of "simple strategies that don't scale" is almost certainly universal. https://upload.wikimedia.org/wikipedia/commons/e/e4/Genome_size_vs_protein_count.svg https://upload.wikimedia.org/wikipedia/commons/e/e4/Genome_s... Eukaryotes, in contrast, scale. It's not an easy task. The strategies are highly elaborate and severely intrusive. They touch the most fundamental, highly conserved aspects of the genome, of cell functionality, and of reproduction. Genes have to be organized hierarchically, packed and unpacked, and everything that interacts with them has to be made compatible with that reality. Further, everything must be done in parallel. The entire architecture of the genome changes as a result. It's like a distributed system vs a monolith. It's a tough, deep-reaching transition to pull off, it's a tougher transition to justify, and that's if you're an engineer capable of things like planning, prediction, and delayed gratification! A greedy optimizer bumbling around in the dark can't rely on cognition (or even a hype cycle!) to propel itself from one mountain range of local optima to another mountain range. I'm sure there are plenty of strategies for scaling genomes, but if they're all difficult -- and the crazy elaborate mechanisms we see in Earth eukaryotes suggest that could be the case -- then they still constitute a filter. But yeah, this is all speculation. Nobody really knows.
- enkid 6y ago
  Certainly everything you say is true for our genetic chemistry, but I don't see a reason why that is necessarily true for all genetic chemistry. For example, our data storage for computers scales from megabytes to gigabytes very well. There's no reason to think there aren't other solutions that scale just as well.
  - ClumsyPilot 6y ago
    If the solutions are trivial, we would see them emerge in the insane amount of time it took to eukariotes to apprear. The fact that they didn't suggest they either do not exist, or are equally difficult.
    - enkid 6y ago
      I'm clearly not articulating this well, so let me try to try another tactic. The evolution of eukaryotes is based on the specific path that Earth went down. The combination of RNA, DNA, proteins, and other cellular chemical building blocks are a way that a cell could be constructed, but not the only possible way a cell could be constructed. For an extreme example, we could have non-carbon based life. If that is true, then all of our assumptions about what is scalable and what is not, based on our biochemistry simple cannot be trusted. So, looking at how long it took for something to develop on Earth tells us basically nothing about how long it would take to do that with this other biochemistry.
      - jjoonathan 6y ago
        I've made the "yes, we know this is speculative" rant in another post. Here I assume you're still interested in moving forward with the speculation. If not, please don't belabor the point. There is a substantial body of abiogenesis experimentation focused on reproducing DNA/RNA proto-life. They haven't managed to make anything that self-replicates, but they have managed to make nucleic acid polymers with catalytic activity, e.g. you zap the primordial soup with lightning, you get a bunch of short sequences, some of those sequences fold into RNA-zymes that catalytically produce long "AAAAAAAAA" sequences or long repeating "AUAUAUAU" sequences. The critical next step is to demonstrate the ability to do this from a template. In any case, are you aware of research that aims to do this with alternative polymer chemistries? Such results could inform our speculation about the likelihood of a fundamental 1000x difference.

by enkid 6y ago

jjoonathan 6y ago

Sure, all of this is speculative, but the eukaryotic jump is notorious for getting casually dismissed on account of being misunderstood. I think it's one of the better candidates for a filter, so let me advocate it for a second and make sure that if you still want to dismiss it's not due to oversight. The problem has nothing to do with having a nucleus. That's the solution. As you note, it's possible to imagine other solutions. The problem is dealing with gigabytes of genetic data instead of mere megabytes. Typically one would use units of base pairs, but in the context of talking about potential alternative forms of life I'd argue that units of information are more appropriate. In any case, the "easy" strategies suffer from a severe dead end that prevents them from going beyond a few megabytes. Lots of things go wrong at that limit, and while other forms of life would encounter those obstacles in slightly different places, the problem of "simple strategies that don't scale" is almost certainly universal. https://upload.wikimedia.org/wikipedia/commons/e/e4/Genome_size_vs_protein_count.svg https://upload.wikimedia.org/wikipedia/commons/e/e4/Genome_s... Eukaryotes, in contrast, scale. It's not an easy task. The strategies are highly elaborate and severely intrusive. They touch the most fundamental, highly conserved aspects of the genome, of cell functionality, and of reproduction. Genes have to be organized hierarchically, packed and unpacked, and everything that interacts with them has to be made compatible with that reality. Further, everything must be done in parallel. The entire architecture of the genome changes as a result. It's like a distributed system vs a monolith. It's a tough, deep-reaching transition to pull off, it's a tougher transition to justify, and that's if you're an engineer capable of things like planning, prediction, and delayed gratification! A greedy optimizer bumbling around in the dark can't rely on cognition (or even a hype cycle!) to propel itself from one mountain range of local optima to another mountain range. I'm sure there are plenty of strategies for scaling genomes, but if they're all difficult -- and the crazy elaborate mechanisms we see in Earth eukaryotes suggest that could be the case -- then they still constitute a filter. But yeah, this is all speculation. Nobody really knows.

enkid 6y ago
Certainly everything you say is true for our genetic chemistry, but I don't see a reason why that is necessarily true for all genetic chemistry. For example, our data storage for computers scales from megabytes to gigabytes very well. There's no reason to think there aren't other solutions that scale just as well.
- ClumsyPilot 6y ago
  If the solutions are trivial, we would see them emerge in the insane amount of time it took to eukariotes to apprear. The fact that they didn't suggest they either do not exist, or are equally difficult.
  - enkid 6y ago
    I'm clearly not articulating this well, so let me try to try another tactic. The evolution of eukaryotes is based on the specific path that Earth went down. The combination of RNA, DNA, proteins, and other cellular chemical building blocks are a way that a cell could be constructed, but not the only possible way a cell could be constructed. For an extreme example, we could have non-carbon based life. If that is true, then all of our assumptions about what is scalable and what is not, based on our biochemistry simple cannot be trusted. So, looking at how long it took for something to develop on Earth tells us basically nothing about how long it would take to do that with this other biochemistry.
    - jjoonathan 6y ago
      I've made the "yes, we know this is speculative" rant in another post. Here I assume you're still interested in moving forward with the speculation. If not, please don't belabor the point. There is a substantial body of abiogenesis experimentation focused on reproducing DNA/RNA proto-life. They haven't managed to make anything that self-replicates, but they have managed to make nucleic acid polymers with catalytic activity, e.g. you zap the primordial soup with lightning, you get a bunch of short sequences, some of those sequences fold into RNA-zymes that catalytically produce long "AAAAAAAAA" sequences or long repeating "AUAUAUAU" sequences. The critical next step is to demonstrate the ability to do this from a template. In any case, are you aware of research that aims to do this with alternative polymer chemistries? Such results could inform our speculation about the likelihood of a fundamental 1000x difference.