The Great Filter

Hoping this will be more fun / less confrontational, but certainly ID and non-ID perspectives will differ. In a nutshell ‘The Great Filter’ is an event that stops life inevitably filling the universe. Others have written much better accounts, so here is your background reading:

The Drake Equation

The Fermi Paradox

The Great Filter

One-stop synopsis if you don’t want the top 3

What do the folks here think? Is there a great filter(s) are we past it / them? My vote is there is at least one ahead of us and we probably won’t make it. Candidates include:

Environmental catastrophe, war using highly potent (N/B/C) weapons, religious zealotry taking us backwards..

I also think other possibilities are flawed assumptions in the Fermi Paradox (maybe marginal / diminishing utility in expansion beyond a certain point, or perhaps transcendence out of this physical realm for sufficiently advanced species. Certainly a million SciFi tropes (Let’s see if we can make a list? Childhood’s End, Mass Effect…) have come from this. What do you folks think?

46 thoughts on “The Great Filter

  1. In a nutshell ‘The Great Filter’ is an event that stops life inevitably filling the universe.

    The greatest barrier is the universe itself. It’s hostile to life. 🙂

  2. .religious zealotry taking us backwards

    I don’t know any religious zealots. Do you have anything specific in mind?

  3. Those hostile to religious ideas/people are more zealous then those zealots we hear about.
    Religious zealots are so few, relative to numbers, that they can’t take us back to whatever was back there.
    the universe was created for mankind to fill in our hundreds of billions and more. lots of room. The original eternity.

  4. Byers:

    Religious zealots are so few, relative to numbers, that they can’t take us back to whatever was back there.

    🙂

  5. Define religious zealot. Abraham seems to have had several children, and lots of grandchildren.

    The world doesn’t revolve around Christianity.

  6. Is the great filter supposedly about spacefaring civilizations?

    I’d say the odds of anything human-like evolving are pretty low. It takes a bunch of contingent events in the right sequence.

    I’d say Dollo’s law is the great filter.

  7. petrushka,

    From the wikipedia article, here are the (some?) possible filters past and future:

    The right star system (including organics and potentially habitable planets)
    Reproductive molecules (e.g., RNA)
    Simple (prokaryotic) single-cell life
    Complex (eukaryotic) single-cell life
    Sexual reproduction
    Multi-cell life
    Tool-using animals with big brains
    Where we are now
    Colonization explosion.

    ETA – you could possibly have big-bang, right constants at the start? (wink wink IDists)

  8. I think there’s a law or at least a relationship that goes something like:

    as a species becomes more developmentally complex and with fewer related species, the probability of extinction approaches 1. I think evolution selects against organisms that become too expensive (resource and energy wise) to sustain.

  9. Richardthughes: Tool-using animals with big brains

    Lots of tool users, and lots of big brains, but the lineage that leads to civilization involves a lot of contingencies. Among other things grains suitable for agriculture and storage.

    I’d bet a couple of dollars that we find evidence of life on an exoplanet within 50 years, but I’m not holding my breath for the discovery of human-like civilizations.

  10. petrushka,

    I suppose you need some sort of agrarian society to allow for specialization, unless food is ubiquitous. maybe in a binary system photosynthesis is possible for larger creatures, etc.

  11. petrushka,

    It only just came to my attention that the earliest evidence of stone tool manufacture predates the emergence of Homo sapiens at an age of around 3.2 – 3.5 million years. Here

  12. Richardthughes:
    Robin,

    https://en.wikipedia.org/wiki/Gaia_hypothesis

    Yes, this I’m familiar with. My view is more organism-oriented and less environment preserving oriented. Basically I just think that as organisms become more complex, they are much more susceptible to catastrophic (or even less catastrophic) elimination.

    Just as an example, the flooding in Baton Rouge is a big deal and has a big effect on humans there. I kind of doubt that any bacteria even noticed.

  13. Richardthughes:
    petrushka,
    I suppose you need some sort of agrarian society to allow for specialization, unless food is ubiquitous. maybe in a binary system photosynthesis is possible for larger creatures, etc.

    I just don’t see any preferred direction to evolution.Conditions that “allow” for big brains and civilization do not cause it to evolve.

  14. petrushka,

    I’m not sure I agree. Intelligence is a good trait for survival, and exists on a continuum amenable for improvement with evolution.

  15. Robin,

    That’s a fair point. I guess the more critical systems an organism has,the more susceptible to failure it is.

  16. Richardthughes:
    Robin,

    That’s a fair point. I guess the more critical systems an organism has,the more susceptible to failure it is.

    Exactly my thinking. There’s a curious parallel with human-developed products: the more complex and compound products become, the less rationale there is to repair them when they break; it becomes much cheaper (though more resource intensive) to simply throw away such items and get new ones.

  17. Elephants are intelligent. Hominids existed for a quarter of a million years without making civilizations. Apparently they nearly went extinct without any help from technology.

  18. Robin: Yes, this I’m familiar with. My view is more organism-oriented and less environment preserving oriented. Basically I just think that as organisms become more complex, they are much more susceptible to catastrophic (or even less catastrophic) elimination.

    I don’t know how being “complex” affects things generally. It does seem that all of life is far more complex now than at some earlier stages.

    As for the matter of intelligence, it seems to create generalists, at least in the case of hominins, which seems to have gotten us through a number of scrapes.

    Just as an example, the flooding in Baton Rouge is a big deal and has a big effect on humans there. I kind of doubt that any bacteria even noticed.

    It wouldn’t have mattered a whole lot to earlier nomadic humans, although death for some of them wouldn’t be all that surprising. The bacteria “notice” a good deal, as some have better opportunities and some lesser opportunities, but (even local) extinction isn’t all that likely for any of them, for many don’t have to eat much at any time, many can form endospores, and scarcity of a bacterium doesn’t cause any problem for finding mates. Predatory and parasitic pressures usually decline as a bacterium species becomes scarce.

    A number of reasons make micro-organisms “tougher”–even as bacteria themselves die at terrific rates–which is why bacteria/archaea type life is what would be most expected on Mars or Europa. Larger animals have always had a more tenuous hold on continuity of life, which won’t change (unless via technology).

    Glen Davidson

  19. Some seem to think that intelligence likely wouldn’t have evolved much before now in our galaxy, especially due to metallicity. True, near the center of the galaxy metal content would go up a good deal earlier, however that’s probably too violent a place for life to evolve uninterrupted by supernovae and gravitational disruptions.

    One thing about intelligent life, it doesn’t seem that planets in the right place and with the right conditions are all that abundant. We’ve got hundreds of exo-planets recorded now, many by methods that can detect an earth-sized planet in the right zone, and we’re still looking for a real match for earth. That said, there probably are at least hundreds in the galaxy, thousands more likely, but things can probably go wrong on many of those, too. No large moon, and intelligence probably doesn’t evolve, and if collisions making large moons aren’t extremely unlikely, it’s probably more the exception than the rule for terrestrial planets. Too many asteroids/comets, and life probably goes back to only micro-organisms again and again, and some systems probably wouldn’t have “clearing out” events like ours had with Jupiter-Saturn resonance (which also seems to have given us a lot of our siderophilic elements, a fact that might be rather important to creating technical civilization). No plate tectonics, and life is probably small and not common–and plate tectonics doesn’t seem inevitable (look at Venus). Too few catastrophes, and we might not get a lot of evolutionary variety. The “right number” and extent of global extinction events might not be easy to achieve on any planet.

    Anyway, it’s hard to say just how likely intelligent life really is, or if it had much chance to develop before ourselves. I really doubt that humans are likely to die off in any apocalypse that might happen fairly soon, and a lot of information about technology and science would almost certainly get through to the post-apocalyptic world. I think the question about continuance after that gets to whether or not they’d really build civilizations like we have now (that might get to the planets soon, although we’ll see), or maybe something quite different. After all, they’d know how badly ours went if apocalypse was caused by human-caused environmental catastrophe, war, etc., and they might opt for some form of fascism to keep control.

    Maybe our present state of knowledge is a fluke that evolution will fix by turning us all into IDists or some such things. We’re probably more believers than we are thinkers, by nature, and if evolution tips us more toward belief, thinking may follow belief as a matter of course, as already occurs with some that we encounter on this forum.

    Glen Davidson

  20. Richardthughes:
    Alan Fox, Please also check out this top, unbiased news site: http://www.uncommondescent.com/animal-minds/macaque-stone-age-culture/

    News at UD has more than once been the the provider of a link to an interesting article. I think I picked up on this one thanks to Denyse, which suggests how far back in time speech centres may have developed, if one is convinced that macaques and humans shared a common ancestor with incipient development of these centres rather than being a case of convergent evolution.

    ETA correct messed up HTML

  21. One problem with the Drake Equation is that it’s a bit planet-centric. Once a species does develop technology to move off-planet (if it ever does), the greatest source of natural, extractable resources it is likely to find are in the icy bodies in the outer parts of a particular star system. Once it has learned to subsist on these, it is likely to no longer need or desire the gravity wells of large planets. An advanced technological species can operate in a very energy-efficient mode, so there’s no reason to assume it will have to use vast quantities of energy.

    And it will not be violating relativity.

    So there could be other advanced civilizations out there that we are unaware of simply because we’re looking at planets, and not icy bodies.

    Another factor to keep in mind is that beyond just developing technology, a space-faring civilization needs to be able to leave that planet. There’s a very narrow range of planetary masses that are large enough to allow a thick atmosphere, plate tectonics, and long-term volcanism and magnetism (all probably necessary for the development of technological life) and yet small enough to allow a chemical rocket to break free of the local gravity to get into orbit or beyond. On Earth, a very large rocket can launch only a very small payload. A planet more massive than Earth might be able to evolve a technological species, but that species might never develop the ability to get into space, just because of the added technological challenge. Humans just barely made it.

  22. The Drake equation has been superseded by the Rare Earth equation. And that has been superseded by the Privileged Planet equation.

  23. Perhaps off topic, but I have always assumed that humans on earth are likely to be one of a kind. The discovery of exoplanets hasn’t changed my mind.

    I don’t see how this is relevant to ID.

  24. I found this:

    The Drake equation should be revised to account for being in the right location within the galaxy. This parameter was not previously known. The resulting modification to the equation will end up reducing the likelihood of other complex technological life in our galaxy. For additional information, refer to Appendix A in the book The Privileged Planet.

  25. Also this:

    But, the main point of The Privileged Planet is not that our situation is “too rare” or “too unlikely” or “too complex.” In fact, this is specifically mentioned to be a poor argument for design in the video and the book (the book actually has a section at the end dealing specifically with objections, similar to this)

    http://www.ideacenter.org/contentmgr/showdetails.php/id/1403

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