9 ms·

Combined with the recent witnessing of evolution of multicellular life[0] the Great Filter seems more and more menacing. [0] - https://www.sciencealert.com/sci

by yreg 6y ago

Combined with the recent witnessing of evolution of multicellular life[0] the Great Filter seems more and more menacing. [0] - https://www.sciencealert.com/scientists-have-witnessed-in-real-time-a-single-celled-algae-evolve-into-a-multicellular-organism https://www.sciencealert.com/scientists-have-witnessed-in-re...

bf404 6y ago
I think it's important, in this case, to distinguish between simple multicellularity where identical cells form clumps (known to have evolved at least 25 times in eukaryotes, as well as in prokaryotes according to https://en.wikipedia.org/wiki/Multicellular_organism https://en.wikipedia.org/wiki/Multicellular_organism - and which has been observed evolving in the lab before your linked paper), multicellularity that has cell differentiation (evolved in 6 groups), and multicellularity that has enough behavioural complexity that we might reasonably expect the emergence of intelligence (only in animals). I don't think simple multicellularity has ever been something that seemed like a likely candidate as a particularly strong filter (although you could argue that it's a weaker filter combined with others)
- yreg 6y ago
  Can you please briefly explain what "multicellularity that has enough behavioural complexity" means? Do we know what were the necessary atributes of those early multicellular organisms without which animals wouldn't be possible?
  - bf404 6y ago
    That was perhaps misleading phrasing. Animals have both true multicellularity (shared with plants, fungi, and some other algae), and much higher behavioural complexity. Multicellularity is almost certainly necessary for behavioural complexity, but it obviously isn't sufficient, because as cool as plants and fungi are, you don't see any of them doing anything that one can imagine leading to intelligence in any form that we'd recognise. Now, broadly, I think (in my capacity as an armchair biologist) what we care about here is an nervous system, or something like it that is capable of fast communication and complex feedback loops that can be built into complex "computation". Interestingly, nervous systems aren't present in sponges, which are most likely the basal animal group (and which are immobile), but are present in all other animals. I'm therefore speculating that "able to develop a nervous system" could be the filter we care about for behavioural complexity. Being non-photosynthetic (so more advantage to being able to move around and find food), not having cell walls (so potentially more able to be motile, and form flexible structures), as well as just whether there are existing cellular pathways that control ion gradients in a way that can be co-opted for communication (which are present in sponges) all seem like plausible things that could predispose a multicellular organism to develop nerves, but if it is a filter, it could well also be that it's really hard to develop something as complicated as nerves, and an early animal got very lucky.
    - azeirah 6y ago
      > because as cool as plants and fungi are, you don't see any of them doing anything that one can imagine leading to intelligence in any form that we'd recognise. Reminds me of a documentary I once watched, watching a timelapse of a vine growing upwards. It grows spiraling, and it looks like it is "looking" for where the walls are, adjusting its trajectory whenever it touches a wall. It's fascinating, and for me it definitely does have some quality of "intelligence" to it.
      - bf404 6y ago
        That's true - and we see that sort of "seeking" behaviour in single celled organisms as well (e.g. https://www.mit.edu/~kardar/teaching/projects/chemotaxis(AndreaSchmidt)/finding_food.htm https://www.mit.edu/~kardar/teaching/projects/chemotaxis(And...) - but this can be explained by a pretty simple feedback loop, and so the the difference in complexity between that and, say, the ability to keep track of different individuals in a social group and reacti differently, is orders of magnitude.
deleted 6y ago
[deleted]
roudaki 6y ago
It's ok to call me stupid but I can't stop thinking about this: it makes sense regardless of what kind of alien intelligent life we are talking about that they will discover fire before solar panels. and we did almost destroyed the global climate with coal. so it always made sense to me that climate change is the first global obstacle that either entire species has to deal with or perish so climate or extreme environmental change is great filter or probably one of great filters. There are two types of naive thinking one is we are children of god and god would never kill all of us and we are deeply rational beings when things get critical we will snap out of it and get things done. I believe in gospel of doubt and that there will be no miracles here. Environmentalists are already abandoning their field and reskilling not only because of lack of funding but lack of public attention and change.
- dimitrios1 6y ago
  > Environmentalists are already abandoning their field and reskilling not only because of lack of funding but lack of public attention and change. That tells me that they weren't all together convinced/interested/passionate about it, so good for them for switching. One thing I've noticed from people who love their field of research and are absolutely convinced of it -- they don't care how much it pays or who believes them. They do it partly because ego (want to be the first or among the first for groundbreaking studies) but mostly because of genuine interest and curiosity and the desire to show the world what they've learned.
- gfodor 6y ago
  Climate change has never struck me as an existential risk. Certainly it is a major problem. But it's slow moving. Slow moving problems are way more soluble than fast moving problems. (For comparison, a hostile AI takeoff theoretically could wipe out humanity in a few minutes given the proper means.) The worst case scenario from climate change itself seems to be a small population of humans living in an artificial habitat in 1000 years. And of course there is a broad spectrum of other outcomes from there. If, for example, we master interplanetary colonization quickly by our effort to get to Mars, this would greatly minimize the impact since we could adapt the technologies used to survive on Mars. The biggest argument in favor of climate change being a true existential risk is if the conflicts it would spawn would result in a global war.
gfodor 6y ago
The Great Filter theory has a very big assumption attached to it, and it's troubling that it's seemingly become accepted as fact by the constant references to "The Great Filter" as a real thing. The assumption is that in a universe with other civilizations we'd certainly be aware of them. I can't say what prior we should have on that, but it's definitely not 100%. Certainly if we find bacteria on Venus all of the claims of "The Great Filter was the creation of cells" will be wrong, and in retrospect it will be shocking to think we could be so ignorant as to be unaware of bacteria on our nearest neighbor for so long. In other words, if it took us this long to find bacteria on Venus, why should we assume anything about our ability to determine life beyond our Solar System?
- yreg 6y ago
  I'm not at all suggesting that the Great Filter is a real thing. I consider the other main solutions of the Fermi Paradox (Alien life being too alien, Simulation Hypothesis, Dark Forest, Zoo and other) just as intriguing! Great Filter is neat because it bundles many different solutions together into one class. Any solution saying that civilizations in the Milky Way are incredibly rare is basically a variation on Great Filter. >why should we assume anything about our ability to determine life beyond our Solar System? It isn't farfetched to assume that sufficiently expansionist/numerous Kardashev type 2+ civilizations should be easier to detect from Earth than bacteria on Venus.
  - Jweb_Guru 6y ago
    > Kardashev type 2+ civilizations I think you are in fact laundering the very large assumption you're making.
    - yreg 6y ago
      If they are contained in their home systems for hundreds upon hundreds of millions of years then the Great Filter is interstellar travel, is it not?
      - 6y ago
jtolds 6y ago
The Great Filter isn't a thing! There is no Fermi paradox! The Drake equation is malformed; multiplying expected values is a bad way to combine probability distributions. https://arxiv.org/abs/1806.02404 https://arxiv.org/abs/1806.02404
- 0xffff2 6y ago
  I only read the abstract, but from that I gather that the paper points out the (rather obvious) fact that the classic Drake equation ignores uncertainty, and that when you put realistic uncertainty bounds on the parameters, the total uncertainty is so large as to make the result meaningless.
  - jtolds 6y ago
    That's a good summary. Here's another good article about it: https://slatestarcodex.com/2018/07/03/ssc-journal-club-dissolving-the-fermi-paradox/ https://slatestarcodex.com/2018/07/03/ssc-journal-club-disso... > Imagine we knew God flipped a coin. If it came up heads, He made 10 billion alien civilization. If it came up tails, He made none besides Earth. Using our one parameter Drake Equation, we determine that on average there should be 5 billion alien civilizations. Since we see zero, that’s quite the paradox, isn’t it? No. In this case the mean is meaningless. It’s not at all surprising that we see zero alien civilizations, it just means the coin must have landed tails.
- MiroF 6y ago
  > The Great Filter isn't a thing! There is no Fermi paradox! Just spent the time to read this whole paper, I think you're misstating some of the claims. A lot of people seem to be confused as to what is stated by the Great Filter/Fermi paradox/Drake equation. First, let's define some terms (from wikipedia!): "The Great Filter, in the context of the Fermi paradox, is whatever prevents non-living matter from undergoing abiogenesis." To be clear, the Great Filter is a solution to the Fermi paradox. If the Great Filter is true, then there is no paradox. The statement that there is no Fermi paradox is not the same as saying there is no Great Filter. This paper suggests that there is a huge amount of uncertainty in $f_l$ and it actually can be quite small, meaning that it is not unlikely that we would see no alien life. (I won't comment on their choice of log-uniform priors, which does not seem intrinsically justified and lets them get much smaller results than if they had just picked uniform) But that is the Great Filter argument! If there is a great filter, that would be a reason why $f_l$ would be lower and the fermi paradox doesn't occur. The paper never suggests that there is no great filter. Now contextualizing to this discovery. If there is life on Venus, that changes our estimate of $f_l$, reducing our uncertainty and increasing the posterior probability mass towards life developing, which means that the fact that we haven't seen life must push the probability of development beyond that stage down or our current state of affairs is more unlikely than it was before. Does that make sense?

by yreg 6y ago

bf404 6y ago

I think it's important, in this case, to distinguish between simple multicellularity where identical cells form clumps (known to have evolved at least 25 times in eukaryotes, as well as in prokaryotes according to https://en.wikipedia.org/wiki/Multicellular_organism https://en.wikipedia.org/wiki/Multicellular_organism - and which has been observed evolving in the lab before your linked paper), multicellularity that has cell differentiation (evolved in 6 groups), and multicellularity that has enough behavioural complexity that we might reasonably expect the emergence of intelligence (only in animals). I don't think simple multicellularity has ever been something that seemed like a likely candidate as a particularly strong filter (although you could argue that it's a weaker filter combined with others)

yreg 6y ago
Can you please briefly explain what "multicellularity that has enough behavioural complexity" means? Do we know what were the necessary atributes of those early multicellular organisms without which animals wouldn't be possible?
- bf404 6y ago
  That was perhaps misleading phrasing. Animals have both true multicellularity (shared with plants, fungi, and some other algae), and much higher behavioural complexity. Multicellularity is almost certainly necessary for behavioural complexity, but it obviously isn't sufficient, because as cool as plants and fungi are, you don't see any of them doing anything that one can imagine leading to intelligence in any form that we'd recognise. Now, broadly, I think (in my capacity as an armchair biologist) what we care about here is an nervous system, or something like it that is capable of fast communication and complex feedback loops that can be built into complex "computation". Interestingly, nervous systems aren't present in sponges, which are most likely the basal animal group (and which are immobile), but are present in all other animals. I'm therefore speculating that "able to develop a nervous system" could be the filter we care about for behavioural complexity. Being non-photosynthetic (so more advantage to being able to move around and find food), not having cell walls (so potentially more able to be motile, and form flexible structures), as well as just whether there are existing cellular pathways that control ion gradients in a way that can be co-opted for communication (which are present in sponges) all seem like plausible things that could predispose a multicellular organism to develop nerves, but if it is a filter, it could well also be that it's really hard to develop something as complicated as nerves, and an early animal got very lucky.
  - azeirah 6y ago
    > because as cool as plants and fungi are, you don't see any of them doing anything that one can imagine leading to intelligence in any form that we'd recognise. Reminds me of a documentary I once watched, watching a timelapse of a vine growing upwards. It grows spiraling, and it looks like it is "looking" for where the walls are, adjusting its trajectory whenever it touches a wall. It's fascinating, and for me it definitely does have some quality of "intelligence" to it.
    - bf404 6y ago
      That's true - and we see that sort of "seeking" behaviour in single celled organisms as well (e.g. https://www.mit.edu/~kardar/teaching/projects/chemotaxis(AndreaSchmidt)/finding_food.htm https://www.mit.edu/~kardar/teaching/projects/chemotaxis(And...) - but this can be explained by a pretty simple feedback loop, and so the the difference in complexity between that and, say, the ability to keep track of different individuals in a social group and reacti differently, is orders of magnitude.

deleted 6y ago

[deleted]

roudaki 6y ago

It's ok to call me stupid but I can't stop thinking about this: it makes sense regardless of what kind of alien intelligent life we are talking about that they will discover fire before solar panels. and we did almost destroyed the global climate with coal. so it always made sense to me that climate change is the first global obstacle that either entire species has to deal with or perish so climate or extreme environmental change is great filter or probably one of great filters. There are two types of naive thinking one is we are children of god and god would never kill all of us and we are deeply rational beings when things get critical we will snap out of it and get things done. I believe in gospel of doubt and that there will be no miracles here. Environmentalists are already abandoning their field and reskilling not only because of lack of funding but lack of public attention and change.

dimitrios1 6y ago
> Environmentalists are already abandoning their field and reskilling not only because of lack of funding but lack of public attention and change. That tells me that they weren't all together convinced/interested/passionate about it, so good for them for switching. One thing I've noticed from people who love their field of research and are absolutely convinced of it -- they don't care how much it pays or who believes them. They do it partly because ego (want to be the first or among the first for groundbreaking studies) but mostly because of genuine interest and curiosity and the desire to show the world what they've learned.
gfodor 6y ago
Climate change has never struck me as an existential risk. Certainly it is a major problem. But it's slow moving. Slow moving problems are way more soluble than fast moving problems. (For comparison, a hostile AI takeoff theoretically could wipe out humanity in a few minutes given the proper means.) The worst case scenario from climate change itself seems to be a small population of humans living in an artificial habitat in 1000 years. And of course there is a broad spectrum of other outcomes from there. If, for example, we master interplanetary colonization quickly by our effort to get to Mars, this would greatly minimize the impact since we could adapt the technologies used to survive on Mars. The biggest argument in favor of climate change being a true existential risk is if the conflicts it would spawn would result in a global war.

gfodor 6y ago

The Great Filter theory has a very big assumption attached to it, and it's troubling that it's seemingly become accepted as fact by the constant references to "The Great Filter" as a real thing. The assumption is that in a universe with other civilizations we'd certainly be aware of them. I can't say what prior we should have on that, but it's definitely not 100%. Certainly if we find bacteria on Venus all of the claims of "The Great Filter was the creation of cells" will be wrong, and in retrospect it will be shocking to think we could be so ignorant as to be unaware of bacteria on our nearest neighbor for so long. In other words, if it took us this long to find bacteria on Venus, why should we assume anything about our ability to determine life beyond our Solar System?

yreg 6y ago
I'm not at all suggesting that the Great Filter is a real thing. I consider the other main solutions of the Fermi Paradox (Alien life being too alien, Simulation Hypothesis, Dark Forest, Zoo and other) just as intriguing! Great Filter is neat because it bundles many different solutions together into one class. Any solution saying that civilizations in the Milky Way are incredibly rare is basically a variation on Great Filter. >why should we assume anything about our ability to determine life beyond our Solar System? It isn't farfetched to assume that sufficiently expansionist/numerous Kardashev type 2+ civilizations should be easier to detect from Earth than bacteria on Venus.
- Jweb_Guru 6y ago
  > Kardashev type 2+ civilizations I think you are in fact laundering the very large assumption you're making.
  - yreg 6y ago
    If they are contained in their home systems for hundreds upon hundreds of millions of years then the Great Filter is interstellar travel, is it not?
    - 6y ago

jtolds 6y ago

The Great Filter isn't a thing! There is no Fermi paradox! The Drake equation is malformed; multiplying expected values is a bad way to combine probability distributions. https://arxiv.org/abs/1806.02404 https://arxiv.org/abs/1806.02404

0xffff2 6y ago
I only read the abstract, but from that I gather that the paper points out the (rather obvious) fact that the classic Drake equation ignores uncertainty, and that when you put realistic uncertainty bounds on the parameters, the total uncertainty is so large as to make the result meaningless.
- jtolds 6y ago
  That's a good summary. Here's another good article about it: https://slatestarcodex.com/2018/07/03/ssc-journal-club-dissolving-the-fermi-paradox/ https://slatestarcodex.com/2018/07/03/ssc-journal-club-disso... > Imagine we knew God flipped a coin. If it came up heads, He made 10 billion alien civilization. If it came up tails, He made none besides Earth. Using our one parameter Drake Equation, we determine that on average there should be 5 billion alien civilizations. Since we see zero, that’s quite the paradox, isn’t it? No. In this case the mean is meaningless. It’s not at all surprising that we see zero alien civilizations, it just means the coin must have landed tails.
MiroF 6y ago
> The Great Filter isn't a thing! There is no Fermi paradox! Just spent the time to read this whole paper, I think you're misstating some of the claims. A lot of people seem to be confused as to what is stated by the Great Filter/Fermi paradox/Drake equation. First, let's define some terms (from wikipedia!): "The Great Filter, in the context of the Fermi paradox, is whatever prevents non-living matter from undergoing abiogenesis." To be clear, the Great Filter is a solution to the Fermi paradox. If the Great Filter is true, then there is no paradox. The statement that there is no Fermi paradox is not the same as saying there is no Great Filter. This paper suggests that there is a huge amount of uncertainty in $f_l$ and it actually can be quite small, meaning that it is not unlikely that we would see no alien life. (I won't comment on their choice of log-uniform priors, which does not seem intrinsically justified and lets them get much smaller results than if they had just picked uniform) But that is the Great Filter argument! If there is a great filter, that would be a reason why $f_l$ would be lower and the fermi paradox doesn't occur. The paper never suggests that there is no great filter. Now contextualizing to this discovery. If there is life on Venus, that changes our estimate of $f_l$, reducing our uncertainty and increasing the posterior probability mass towards life developing, which means that the fact that we haven't seen life must push the probability of development beyond that stage down or our current state of affairs is more unlikely than it was before. Does that make sense?