5 ms·

> thankfully this isn't how it works. Care to elaborate what lowers this probability down to "computable within adolescent age" levels?

empath75 2y ago
You want people to explain natural selection and evolution to you?
- treprinum 2y ago
  No, I want the computational feasibility explanation with some nice O(function) on biological processes. To the best of my knowledge, we still have no idea. Something like "the computational complexity of a beached fish to invent and grow a leg is O(n^2 log n) hours where n is the number of neural spikes in frontal cortex" or similar.
  - deleted 2y ago
    [deleted]
  - TeMPOraL 2y ago
    Fish aren't the only things that live in water. There are other marine organisms, some of which have leg-like things. What if one of those organisms, already equipped with legs, evolved to survive on the surface?
    - treprinum 2y ago
      That would be fine; but we have some lineages coming from fish living on the surface. Those are the interesting ones.
      - TeMPOraL 2y ago
        While metabolic advantage is a thing, I'm not sure if organisms are expected to carry minimum amount of genetic code that they actually use; in what little I know about developmental biology, I recall there's a high-level structure to the genetic code - some genes are doing more of flow control than encoding actual proteins. It's conceivable that the fish which walked on Earth was the one that managed to accumulate inactive adaptations for walking and switched them on. Also, there's horizontal gene transfer to account for. It further complicates the picture.
        exe34 2y ago
        > one that managed to accumulate inactive adaptations for walking and switched them on. https://www.discoverwildlife.com/animal-facts/fish/can-fish-walk https://www.discoverwildlife.com/animal-facts/fish/can-fish-... Genes get duplicated by accident, then accumulate mutations which are usually neutral or worse. Occasionally they help you achieve something slightly more useful than before. Lobed fins that helped you heave yourself back into water when you get beached would have helped. bigger lobed fins would help you get back when stranded further up the beach, or get from pool to pool. It's unlikely that an entire set of limbs, other necessary body upgrades to support them and neural circuits would just hang around waiting for all the right mutations to collect like hole punches on a restaurant loyalty card before some critter slapped their thighs and stood up and walked. Evolution does not plan ahead.
        treprinum 2y ago
        This argument is however an argument from faith and not from computability perspective. Random garbage genes flipped on won't grow a leg with intricate mechanical abilities. Those abilities have to be computed somewhere and need to be useful right from the start to appear in offsprings otherwise they get eliminated as a waste. Yet everyone puts their faith in some random process instead of pinning down the concrete mechanisms how does this happen. So you basically end up forcing some idiotic faith on everyone instead of digging deep and figuring it finally out. I would be more inclined to believe if you told me that pre-adolescent brain spends 25% of its computing capacity on figuring out how to improve its body and encoding it into genes instead of trusting some random mutation (likely error-corrected) to do the heavy lifting.
        TeMPOraL 2y ago
        It's not a faith thing. Yes, metabolic advantage is a thing and useless adaptations can get eliminated over time (it seems to matter more in single-cellular organisms, though). However, often enough, unused adaptations can persist for a long time - for example, pythons still have the whole blueprint for "a leg with intricate mechanical abilities" and nerves and stuff, it's literally just switched off. We know because some researchers figured out how to flip it back on, and behold, snakes grew their legs back. That's what I've been alluding to in the prior comment - genes aren't encoding a flat blueprint, but a complex program with many genes working as flow control or signalling superstructure, able to toggle or modify whole complex body parts.
  - immibis 2y ago
    Have you ever tried genetic algorithms?
    - treprinum 2y ago
      Those are great models for local adaptations. They won't grow a leg with extricate mechanical properties we have trouble modeling in state-of-art robotics/mechanics.
      - immibis 2y ago
        I didn't say it had to simulate real physics. Have you ever tried *a* genetic algorithm? They grow legs all the time in their toy universes, if that helps them increase their objective function.
        briffid 2y ago
        All genetic algorithms are created by conscious intelligent beings. So I'm more interested in how a genetic algorithm develops by chance, with what probability. I guess typing monkeys wouldn't create genetic algorithms in the existing universe's timeframe even if the monkeys themselves have some (also random) fitness function that by chance has the ability to replace dumb monkeys with smarter ones.
        immibis 2y ago
        Genetic algorithms are everywhere. Every time (1) something copies itself with mistakes, and (2) ....... actually there's just (1), no (2). Every time things copy themselves imperfectly, you have a genetic algorithm, and the fitness function is how much they copy themselves in the long run. The current best hypothesis is that RNA randomly developed and evolved. Some if it happened to be self-copying. If there are self-copying things, there will be lots of self-copying things - that's common sense. And a genetic algorithm fitness function. In an ocean with RNA, sometimes it will happen to bump into other bits of RNA and swap over. Sometimes they randomly get better at copying. Zillions of molecules and hundreds of millions of years is a long time for small chances to happen. We want genetic algorithms to run in seconds on a PC. Ones that run for millions of years in the Earth's whole ocean don't have to be nearly as good. The Miller-Urey experiment demonstrated that chemicals we know as building blocks of life can come into existence by themselves in early Earth conditions. What we don't know yet is exactly how they got from there to cells, since we don't have a time machine to go and look. Scientists keep finding plausible stepping stones, though.
exe34 2y ago
I offer paid tuition. For £50/h, I will learn stuff for you and then teach you. Prep time is typically ~3h for each hour I teach you. Minimum 1h lessons.
- treprinum 2y ago
  I will pay you £50,000/h if you could give me a convincing answer like "the computational complexity of a beached fish to invent and grow a leg is O(n^2 log n) hours where n is the number of neural spikes in frontal cortex".
  - exe34 2y ago
    a beached fish doesn't grow legs. the problem isn't what you're willing to pay here, the problem is what you are willing to learn. my fees are not conditional on you liking the lessons. they are to be paid upfront. i accept the higher offer though.
    - treprinum 2y ago
      > a beached fish doesn't grow legs Can you prove it? Show me some sort of an environment where a water-based complex organism is able to survive and thrive in dry environment prompting it to grow a new movement organ useless in the water but needed on surface and give me some less-than-exponential algorithmic complexity bound for it. If you can't do it, you don't offer valuable lessons.
      - jjk166 2y ago
        The Lungfish survives prolonged droughts where its freshwater habitat dries up. It has evolved the ability to breath fresh air, secrete a mucous membrane to form a protective cocoon that helps it retain moitsture, and its fins are heavily modified to aid with land based locomotion. Lungfish are the closest relatives to tetrapods who likely evolved under similar conditions. https://education.nationalgeographic.org/resource/west-african-lungfish/ https://education.nationalgeographic.org/resource/west-afric...

empath75 2y ago

You want people to explain natural selection and evolution to you?

treprinum 2y ago
No, I want the computational feasibility explanation with some nice O(function) on biological processes. To the best of my knowledge, we still have no idea. Something like "the computational complexity of a beached fish to invent and grow a leg is O(n^2 log n) hours where n is the number of neural spikes in frontal cortex" or similar.
- deleted 2y ago
  [deleted]
- TeMPOraL 2y ago
  Fish aren't the only things that live in water. There are other marine organisms, some of which have leg-like things. What if one of those organisms, already equipped with legs, evolved to survive on the surface?
  - treprinum 2y ago
    That would be fine; but we have some lineages coming from fish living on the surface. Those are the interesting ones.
    - TeMPOraL 2y ago
      While metabolic advantage is a thing, I'm not sure if organisms are expected to carry minimum amount of genetic code that they actually use; in what little I know about developmental biology, I recall there's a high-level structure to the genetic code - some genes are doing more of flow control than encoding actual proteins. It's conceivable that the fish which walked on Earth was the one that managed to accumulate inactive adaptations for walking and switched them on. Also, there's horizontal gene transfer to account for. It further complicates the picture.
      - exe34 2y ago
        > one that managed to accumulate inactive adaptations for walking and switched them on. https://www.discoverwildlife.com/animal-facts/fish/can-fish-walk https://www.discoverwildlife.com/animal-facts/fish/can-fish-... Genes get duplicated by accident, then accumulate mutations which are usually neutral or worse. Occasionally they help you achieve something slightly more useful than before. Lobed fins that helped you heave yourself back into water when you get beached would have helped. bigger lobed fins would help you get back when stranded further up the beach, or get from pool to pool. It's unlikely that an entire set of limbs, other necessary body upgrades to support them and neural circuits would just hang around waiting for all the right mutations to collect like hole punches on a restaurant loyalty card before some critter slapped their thighs and stood up and walked. Evolution does not plan ahead.
        treprinum 2y ago
        This argument is however an argument from faith and not from computability perspective. Random garbage genes flipped on won't grow a leg with intricate mechanical abilities. Those abilities have to be computed somewhere and need to be useful right from the start to appear in offsprings otherwise they get eliminated as a waste. Yet everyone puts their faith in some random process instead of pinning down the concrete mechanisms how does this happen. So you basically end up forcing some idiotic faith on everyone instead of digging deep and figuring it finally out. I would be more inclined to believe if you told me that pre-adolescent brain spends 25% of its computing capacity on figuring out how to improve its body and encoding it into genes instead of trusting some random mutation (likely error-corrected) to do the heavy lifting.
        TeMPOraL 2y ago
        It's not a faith thing. Yes, metabolic advantage is a thing and useless adaptations can get eliminated over time (it seems to matter more in single-cellular organisms, though). However, often enough, unused adaptations can persist for a long time - for example, pythons still have the whole blueprint for "a leg with intricate mechanical abilities" and nerves and stuff, it's literally just switched off. We know because some researchers figured out how to flip it back on, and behold, snakes grew their legs back. That's what I've been alluding to in the prior comment - genes aren't encoding a flat blueprint, but a complex program with many genes working as flow control or signalling superstructure, able to toggle or modify whole complex body parts.
- immibis 2y ago
  Have you ever tried genetic algorithms?
  - treprinum 2y ago
    Those are great models for local adaptations. They won't grow a leg with extricate mechanical properties we have trouble modeling in state-of-art robotics/mechanics.
    - immibis 2y ago
      I didn't say it had to simulate real physics. Have you ever tried *a* genetic algorithm? They grow legs all the time in their toy universes, if that helps them increase their objective function.
      - briffid 2y ago
        All genetic algorithms are created by conscious intelligent beings. So I'm more interested in how a genetic algorithm develops by chance, with what probability. I guess typing monkeys wouldn't create genetic algorithms in the existing universe's timeframe even if the monkeys themselves have some (also random) fitness function that by chance has the ability to replace dumb monkeys with smarter ones.
        immibis 2y ago
        Genetic algorithms are everywhere. Every time (1) something copies itself with mistakes, and (2) ....... actually there's just (1), no (2). Every time things copy themselves imperfectly, you have a genetic algorithm, and the fitness function is how much they copy themselves in the long run. The current best hypothesis is that RNA randomly developed and evolved. Some if it happened to be self-copying. If there are self-copying things, there will be lots of self-copying things - that's common sense. And a genetic algorithm fitness function. In an ocean with RNA, sometimes it will happen to bump into other bits of RNA and swap over. Sometimes they randomly get better at copying. Zillions of molecules and hundreds of millions of years is a long time for small chances to happen. We want genetic algorithms to run in seconds on a PC. Ones that run for millions of years in the Earth's whole ocean don't have to be nearly as good. The Miller-Urey experiment demonstrated that chemicals we know as building blocks of life can come into existence by themselves in early Earth conditions. What we don't know yet is exactly how they got from there to cells, since we don't have a time machine to go and look. Scientists keep finding plausible stepping stones, though.

exe34 2y ago

I offer paid tuition. For £50/h, I will learn stuff for you and then teach you. Prep time is typically ~3h for each hour I teach you. Minimum 1h lessons.

treprinum 2y ago
I will pay you £50,000/h if you could give me a convincing answer like "the computational complexity of a beached fish to invent and grow a leg is O(n^2 log n) hours where n is the number of neural spikes in frontal cortex".
- exe34 2y ago
  a beached fish doesn't grow legs. the problem isn't what you're willing to pay here, the problem is what you are willing to learn. my fees are not conditional on you liking the lessons. they are to be paid upfront. i accept the higher offer though.
  - treprinum 2y ago
    > a beached fish doesn't grow legs Can you prove it? Show me some sort of an environment where a water-based complex organism is able to survive and thrive in dry environment prompting it to grow a new movement organ useless in the water but needed on surface and give me some less-than-exponential algorithmic complexity bound for it. If you can't do it, you don't offer valuable lessons.
    - jjk166 2y ago
      The Lungfish survives prolonged droughts where its freshwater habitat dries up. It has evolved the ability to breath fresh air, secrete a mucous membrane to form a protective cocoon that helps it retain moitsture, and its fins are heavily modified to aid with land based locomotion. Lungfish are the closest relatives to tetrapods who likely evolved under similar conditions. https://education.nationalgeographic.org/resource/west-african-lungfish/ https://education.nationalgeographic.org/resource/west-afric...