5 ms·

The last years have given us two estimates of previously unknown factors in the Drake equation, that's why everybody is excited. Yes, life could be very improb

by Iv 7y ago

The last years have given us two estimates of previously unknown factors in the Drake equation, that's why everybody is excited. Yes, life could be very improbable to appear, but there is a counterargument to this hypothesis: on our planet, life appeared almost immediately once the crust solidified and oceans appeared. If there had been a 3 billion years period, there may have been an argument that maybe we got very lucky it appeared at all, but we have fossils that are just 100 mil years younger than the apparition of oceans. And we keep finding older ones. If life was a really rare occurrence that would mean we would have been lucky twice: that it appeared at all and that it appeared that early. > Does this lower or increase that such a filter would be behind us or before us? When so many things are unknown, it makes little sense to talk about probabilities. It removes a possibility for a filter behind us. I still have doubts that evolution necessary leads to intelligent life. When I started getting interested into evolution, my main surprise was that there is no "optimal" unicellular life-form. Why isn't the earth covered by a green pellicule of photosynthesis-able cells that would be a Kardashev I organism without ever reaching intelligence? I still don't understand why it did not happen. Evolution favored competition to optimality and the reasons are unclear. I would not be surprised that evolution in other ecosystems would result in one organism "winning" over all the others. My personal opinion is that we will find a lot of life on other planets, but many will be unicellular and many will show an evolutionary process that is stuck in a dead-end. I expect intelligent life to be rare, and that the "great filter" is that we will find things much more worthy of our time and energy than colonizing the universe or doing mega-engineering projects. Maybe we'll colonize a few star, build a Dyson star or two, but then we will discover that everyone prefers to spend time in another dimension, or in infinite pocket-universes. Maybe the real party is inside the black holes or the neutron stars and all the advanced civilizations are waiting for us to figure it out. The idea that an intelligent species would colonize the universe assumes that it does not manage to handle its demography or views its growth as a good thing. I doubt that this is a rational conclusion once you reached the state of full automation.

xornox 7y ago
Green unicellular life-form is perfect food and energy source same way as energy of sun is. Evolution does not stop if there are easy energy sources available everywhere. Nature does not care if energy of sun is used optimally or not. It just cares if offsprings live or not.
- Iv 7y ago
  I think it is very easy to imagine a local minima in which evolution would be stuck. Making a membrane far too hard to pierce could starve a predator into extinction instead of making it evolve. If you reach a point where one organism developed enough mechanisms to resist simple predators and that their advanced predators die out, I think it would be impossible for evolution to get out of that dead end. I am not sure that getting unstuck is a universal feature of life. Emergence of sexual reproduction, of multi-cellular organisms, are all very weird phenomenon that I think are risky to take for granted. I mean, it feels like playing Conway's game of life: Often, when you start a random one, it all dies out. It often gets stuck in a position where just a few things vibrates. Some last longer. Others go on forever but are rarer. My intuition (which can be dismissed without argument) is that life is similar: if the conditions are right, it may lead to emergent evolutionary behaviors that eventually can lead to intelligent life, but that's not the most common outcome.
  - Isinlor 7y ago
    > If you reach a point where one organism developed enough mechanisms to resist simple predators and that their advanced predators die out, I think it would be impossible for evolution to get out of that dead end. Evolution works on the level of individuals. Even if you end up in a situation where you have only clones of a single organism populating whole planet, these clones will compete with each other. Because of different environmental conditions, random mutations and distances this super successful organism most likely will still undergo speciation.
    - Iv 7y ago
      But what if you have already reach optimal growth and optimal energy efficiency? If you have ever played with evolutionary algorithm, you have seen that it is very easy for a system to just "win". Want to optimize a thing that heavily depends on a mass/surface ratio? Oh, a sphere is the perfect solution. Evolution can't beat it. Yes, maybe there can be various colonies of photosynthetic organisms competing over millionth of percents of efficiency for billions of years. That's what I call a dead end of evolution.
Tuna-Fish 7y ago
And the year before that gave us Dissolving the Fermi paradox[1], which conclusively shows that the drake equation is not worth the napkin it's written on. tl;dr: It is possible for both of the following statements to be true at the same time: (1) The Drake equation gives a true estimate for the mean amount of extant civilizations in the galaxy, and that estimate is relatively large. (As in, much greater than one.) (2) The probability of sentient life existing outside our solar system is infinitesimally small. The reason for this is that the Drake equation gives a mean over all possible universes, with the solution space created by our uncertainty in the parameters. Since all of the parameters have more uncertainty in one direction than the other, the probability distribution is not symmetrical, and so the mean, mode and median are not the same. In fact, it turns out that when you do the math right, you find that essentially all of the probability mass in the Drake equation comes from the cases where almost every star has a civilization around it. Using our current best estimate numbers, and excluding the cases we can conclusively disprove because we are not already chatting with our neighbors at Proxima Centauri, P(we are alone in the galaxy) > 50%, and P(we are alone in the observable universe) > 39%. [1]https://arxiv.org/abs/1806.02404 https://arxiv.org/abs/1806.02404

by Iv 7y ago

xornox 7y ago

Green unicellular life-form is perfect food and energy source same way as energy of sun is. Evolution does not stop if there are easy energy sources available everywhere. Nature does not care if energy of sun is used optimally or not. It just cares if offsprings live or not.

Iv 7y ago
I think it is very easy to imagine a local minima in which evolution would be stuck. Making a membrane far too hard to pierce could starve a predator into extinction instead of making it evolve. If you reach a point where one organism developed enough mechanisms to resist simple predators and that their advanced predators die out, I think it would be impossible for evolution to get out of that dead end. I am not sure that getting unstuck is a universal feature of life. Emergence of sexual reproduction, of multi-cellular organisms, are all very weird phenomenon that I think are risky to take for granted. I mean, it feels like playing Conway's game of life: Often, when you start a random one, it all dies out. It often gets stuck in a position where just a few things vibrates. Some last longer. Others go on forever but are rarer. My intuition (which can be dismissed without argument) is that life is similar: if the conditions are right, it may lead to emergent evolutionary behaviors that eventually can lead to intelligent life, but that's not the most common outcome.
- Isinlor 7y ago
  > If you reach a point where one organism developed enough mechanisms to resist simple predators and that their advanced predators die out, I think it would be impossible for evolution to get out of that dead end. Evolution works on the level of individuals. Even if you end up in a situation where you have only clones of a single organism populating whole planet, these clones will compete with each other. Because of different environmental conditions, random mutations and distances this super successful organism most likely will still undergo speciation.
  - Iv 7y ago
    But what if you have already reach optimal growth and optimal energy efficiency? If you have ever played with evolutionary algorithm, you have seen that it is very easy for a system to just "win". Want to optimize a thing that heavily depends on a mass/surface ratio? Oh, a sphere is the perfect solution. Evolution can't beat it. Yes, maybe there can be various colonies of photosynthetic organisms competing over millionth of percents of efficiency for billions of years. That's what I call a dead end of evolution.

Tuna-Fish 7y ago

And the year before that gave us Dissolving the Fermi paradox[1], which conclusively shows that the drake equation is not worth the napkin it's written on. tl;dr: It is possible for both of the following statements to be true at the same time: (1) The Drake equation gives a true estimate for the mean amount of extant civilizations in the galaxy, and that estimate is relatively large. (As in, much greater than one.) (2) The probability of sentient life existing outside our solar system is infinitesimally small. The reason for this is that the Drake equation gives a mean over all possible universes, with the solution space created by our uncertainty in the parameters. Since all of the parameters have more uncertainty in one direction than the other, the probability distribution is not symmetrical, and so the mean, mode and median are not the same. In fact, it turns out that when you do the math right, you find that essentially all of the probability mass in the Drake equation comes from the cases where almost every star has a civilization around it. Using our current best estimate numbers, and excluding the cases we can conclusively disprove because we are not already chatting with our neighbors at Proxima Centauri, P(we are alone in the galaxy) > 50%, and P(we are alone in the observable universe) > 39%. [1]https://arxiv.org/abs/1806.02404 https://arxiv.org/abs/1806.02404