> A more inclusive representation is to recognize a spectrum between the non-living and the living—a “grayness” resulting from the protracted evolutionary process that gave rise to life.
The meaning of "grayness" would appear to have something to do with the fuzzy line between life and non-life.
There is a footnote to the article "The Seven Pillars of Life":
This gets cleared up a little a few paragraphs in:
> The ability to clearly distinguish between abiotic and biotic systems is considered by many a prerequisite for effective astrobiology studies. However, since no natural demarcation truly exists, there is a profound difficulty in advancing the field if we rely on a strict dichotomy. ...
Yes, viruses have organic molecules, information storage systems, and compartmentalization. No, viruses do not have metal catalysis (correct me if I’m wrong) nor do they have energy currencies (they rely on hosts for energy). Viruses appear rather gray indeed.
Can the grayness framework be modified/extended to describe superorganisms?
Superorganisms like bee colonies are only mentioned in passing and the authors do not try to apply their grayness framework. Organic molecules and metal catalysis aren’t as relevant beyond the molecular scale, but information storage systems, energy currencies, and compartmentalization apply just as well to superorganisms. Perhaps those are the more generalizable attributes of life.
I’m reminded of concepts from Schrödinger’s What Is Life?. Schrödinger describes local reduction of entropy to be a key feature — combining energy currencies with compartmentalization is one way to achieve that. Separately, he discusses the hereditary mechanism and suggests an “aperiodic crystal” could encode heritable information.
What would be the contents of a sister article titled “The Grayness of the Origin of Consciousness”?
I find it fascinating that abiotic chemical/physical cycles are considered an integral part of early life (e.g. if your nutrient transport is environmental osmosis/tides/whatever, you're still alive but the larger environment is an integral part of your biochemistry).
From that perspective the freshwater cycle is still a major component of biochemistry (bulk ion transport) on Earth, despite arguably being a physical state change and not chemistry per se.
The Sun provides photons that most cells need in order to live but Desulforudis audaxviator have decoupled themselves from that source of energy. In theory they could outlast the solar system or hitch a ride on a rogue planet.
>The Sun provides photons that most cells need in order to live but Desulforudis audaxviator have decoupled themselves from that source of energy. In theory they could outlast the solar system or hitch a ride on a rogue planet.
I suspect it's the opposite; first there was life and then it evolved to use sunlight.
How did life arise on earth right after the rocks stopped being red hot? The only reasonable theory in my opinion is that the original life forms were inside the rocks on some jetsam that wasn't totally molten and if you go back further, lived off a little heat and water underground, quite possibly on a "rogue planet".
One reason this seems obvious to me is that there must be orders of magnitude more planets without stars than with. Just like there are more asteroids than planets, more dim red stars than sun-like stars, etc.
The other reason is that I think it helps a great deal with the Fermi paradox. If life just zapped into existence on Earth, 4.5 billion years ago, then it could've happened at any time, anywhere else, over the prior (almost) 10 billion years or so.
But if it took most of that time, since the Big Bang, to develop what we think of as the most primitive life, in the much larger arena of rubble or rogue planets in deep space, then it looks more like we are the earliest life that could develop, and that's why we wouldn't have been overrun by space invaders.
Looking the exponential development of life, even if you choose somewhat arbitrary milestones, it's basically a self-similar curve; each "step" takes a fraction of the previous one. Going backwards, each step should take the corresponding multiple. The great oxidation event was about 2.5 billion years ago. The first life we know about was about twice that. It seems to me a near perfect fit, timing wise, for the origin of that life to be about twice that ago, rather than suddenly arise from nothing in a few million years.
What it comes down to is I think creationists who are skeptical of abiogenesis really have a good point, about how the simplest life is unbelievably complex, in spite of not having a viable theory to explain it. But I think the answer is staring us in the face.
And of course panspermia isn't new or my idea particularly, but what bugs me is instead of saying there needs to be more evidence, it should be the default assumption. Our environment is just not representative of most of the universe even if you ignore non-baryonic dark matter.
> And of course panspermia isn't new or my idea particularly, but what bugs me is instead of saying there needs to be more evidence, it should be the default assumption. Our environment is just not representative of most of the universe even if you ignore non-baryonic dark matter.
One might dismiss this by invoking the anthropic principle (a blunt argument, sorry). Most of the universe is void, and planets with no sun have little energy being tossed into their closed system. It seems adding whatever the hell can be found on asteroids into a planet bombarded by energy (a star being most convenient) is a necessary catalyst for life.
I'm sure I haven't thought about this as much as you have. What makes you think life can be formed without the presence of a star? Is it simply how much more not-near-a-star places there are?
If panspermia is true, I think it’s most likely life evolved on a planet orbiting a star. It just seems to me that the energy availability and chances of having liquid water are more conducive.
That planet then was destroyed or fragments broken off, scattering life enriched matter into star forming nebulae. This seeded more planets, which then broke up scattering more life enriched matter. After several cycles of this you’d end up with life, or at least sophisticated organic molecule enriched matter all over the galaxy.
>It just seems to me that the energy availability and chances of having liquid water are more conducive.
It seems to me the very concept of a "habitable zone" tends to imply liquid water on the surface of a planet is implausible/rare. There's a whole bunch of additional requirements besides distance and temperature, which some people think makes life in red dwarf systems doubtful, and even looking at earth's history, surface dwelling life seems precarious with all the extinction events.
And we have Enceladus as an example of the alternative. There must be orders of magnitude more bodies like this, with undersea oceans and some internal warmth, than bodies with surface conditions conducive to life. Perhaps life needs an environment like earth to develop fully, but if 99.x% of the potential habitat for the most basic life is indifferent to our particular conditions, then it seems to me overwhelmingly likely that's where it started.
> despite arguably being a physical state change and not chemistry per se.
It remove salt from the water but more importantly move it to the top of mountains, which adds energy into the system.
Chemistry happens when the water disolves sediments and carry them back to the oceans.
I'm personally convinced at this point that most everyday distinctions between living and dead are arbitrary human categorizations. Even a "dead body" is teaming with life. As far as "inanimate matter" is concerned, all matter is ultimately part of a plethora of various different cycles and processes of transformation and recapitulation... even if something temporarily looks like it's static to us and our meager little narrow timeframe of experience, it's not.
Just to clarify, I don't mean that these distinctions are meaningless, just that their meaning is inherently embedded in human experience.
I don’t think it’s arbitrary. There’s a clear distinction between say a rock and a cell, even if you view the rock on geological timescales and the cell on biological timescales. I don’t think it’s arbitrary or even surprising that humans view things from our own vantage point in reality.
There's a negative consequence - If the line between life and non-life is blurry, that means there isn't a clear place for souls to fit in. If life can be completely explained as an emergent property of individual non-living parts, (ultimately, atoms aren't alive, even though they make up living things) then we can't tell whether souls exist in our universe or not.
This isn't a big deal for science, but it's a moral victory for atheists.
> If the line between life and non-life is blurry, that means there isn't a clear place for souls to fit in
If "souls" aren't defined precisely enough that there's an experiment that give different results depending on whether they exist, then the statement "souls exist" is meaningless, and anyone saying it is not even wrong.
> This isn't a big deal for science, but it's a moral victory for atheists.
Theists won't care, although I suppose some will mutter something about separate magisteria.
The concept of a soul is a rich one, and for many people is largely metaphorical or figurative. You can subscribe to a materialist account of our cosmos and still draw meaning from the idea of a soul.
a metaphysical victory for atheists who consumes the concept of soul would be that the concept ceases, which is equivalent to its physical death in the competing theist's view, and completely unconsequential to the atheist, which only proves that atheism is at least not that bad.
That isn't necessarily true. All you have to do to keep the concept of external soul alive is to accept the idea of simpler souls. Maybe there isn't am irreducibly complex soul.
I guess mean arbitrary in the sense that being born as a human is kinda arbitrary, in the sense that individual human perspectives themselves are arbitrary amongst the vast range of possible ways to experience or perceive, both human and beyond human.
Well and also in the sense that it takes some pretty arbitrary decisions to distinguish living from nonliving.
I don't mean that these distinctions are useless or unimportant, just that for the most part they may not be all that fundamental... You end up drawing lines in the sand.
For example, are you gonna exclude viruses from the tree of life? Why? Because viruses don't have any known local macroscopic motility? Because they rely too heavily on their environment ("host") to reproduce? Those are summaries of the arguments I've heard against viruses being alive, and imo they're pretty arbitrary.
On the other hand, viruses reproduce and are subject to selective pressures, as are most phenomena with a lifecycle and an external environment. So then if you include viruses are you gonna include RNA? What about reactions, e.g. combustion? Are these alive? Well then and what about consumer product/producer systems? Don't they have lifecycles of their own? Some feedback loops that cause selective pressures? Environments to survive and reproduce in?
It's fuzzy.
A lot of rational, materialistic categorizations of living vs unliving look to me like hunches based on assumptions about motility or consciousness, and might as well be reframed as "does it move?" or "can I communicate with it?" or "does it see me?"
Lynn Margulis and Dorion Sagan wrote a nice essay called "the uncut self" that's really great and related to this in my view. It's all about where the tendency to draw boundaries around "individual selves" when looking at living systems, boundaries that might not be so fixed or obvious when you look carefully.
I think it's simpler than you're allowing. Death in animals is the absence of consciousness with no possibility of recovery. In plants and maybe-but-probably-not-sentient life, it's more complicated.
We all agree when we should say that a cow is dead, but what about sponges? You can pass a sponge through a sieve, and the isolated cells will recombine https://www.shapeoflife.org/video/sponges-time-lapse-sponge-... (Is there a better link?) Can a single cell of a sponge create a "new" sponge? Or it's just the "old" sponge? Should you wait until the last cell is dead until we can claim it's dead?
Back to cows...
You can remove the heart of a cow and keep the heart alive in a proper device, and keep the rest of the cow alive with an artificial heart. (I don't know if someone has tried this with cows, but this should be possible with the same technology for hearts transplants in humans.)
Are both parts alive? What happens if I unplug one of them? Is the heart-less-cow is the real cow? I think we all agree about this last question, but from the cellular level it's just an arbitrary classification, in spite it's useful for us.
It's not a matter of arbitrary classification in the cow case. The original definition still works. The heart has no experience. The continuum of consciousness exists solely within the heartless cow. Whether you want to call the heart "alive" is the same as the question about plants and sponges.
Experience is not a function of a simple "level of complexity" but of structure with specific function. The idea that you reach a certain level of complexity and just get sentience as an incidental side effect of the complexity is a fallacy for multiple reasons. Sentience results from structures specifically crafted to create sentience. In the 21st century as opposed to the 12th century we know for sure that the structures that give us sentience reside entirely in the brain. We can examine the highly complex structure of the heart and compare it to the brain and see that while the heart is complex it does not have the same structure as the brain. The heart is not sentient not because it lacks sufficient "level of complexity" but rather because it lacks a specific functional form of complexity, i.e. the heart lacks information processing structures that the brain has. We can also observe things like when there is a heart transplant the recpient does not start experiencing a change in personality from an independent "sentient" donor heart. Thus there is no evidence that sentience resides outside the brain, so why assume it might?
You could just as well assume that a rock has the processing power of a computer CPU but it just lacks input and output.
The heart of a cow (and any vertebrate) can beat on it's own. Each muscular cell of the heart beats, and they coordinate the beating when they are in contact. Also, there are a lot of neurons in the heart to synchronize the beating of the different parts of the heart.
IIRC It can keep beating even without brain signals. It's not the ideal rate of beating, and there are other problems, but the heart somewhat beats on it's own.
I don't know how many sensing neurons the heart have and how they interact with the beating. The heart is not as "smart" as a brain, but it's "smarter" than a rock.
Stealing the examples from other comments: Is the heart of a cow smarter than a planaria? Is the heart of a cow smarter than a hydra?
Yeah the heart can beat according to its internal pace maker and a CNC machine can move about and cut a work piece according to its internal program. We have no reason to believe that either is sentient. Maybe a thousand or so years ago when people did not fully understand that the brain is where consciousness takes place. Nowadays there is no excuse. Autonomy is not sentience. Your heart does not have feelings or a sense of self. Evolution did not require that to build a somewhat self regulating muscular pump. The rock vs. cpu example was a little hyperbolic I guess.
My point is simply the presence of interconnected neurons running a certain program is not sufficient to give rise to sentience or conciousness. I believe what we call sentience or conciousness is not an accident or even really an "emergent" phenomenon but rather the direct, purposeful result of specific structure that was selected for by evolution.
The phrase "level of complexity" is inartful because it implies there is one axis or dimension to complexity when that is not the case. If you make a random soup of 100 billion interconnected neurons and teach it to classify images it is highly unlikely that you will get a sentient being by accident although you may have a very efficient neural network at the task it was designed for. If however you take a 100 billion neurons and subject them to the selective pressures of evolution in the real world, where a sentient or self aware self may have advantage then it is not unlikely perhaps that you end up with a sentient or counscious being. Thus sentience is the result of specific selected for structure not the random outcome of a certain level of complexity. I don't see why this is even contraversial.
General intelligence does not exist divorced from the real world and it does not just happen as the side effect of a certian "level" of complexity.
With regard to the question is the heart of a cow smarter than a planiar (worm) whole organism I do not see this as a meaningful question because the starting premise is wrong. The starting premise assumes that there is some abstract quality "sentience" or "intelligence" that exists on a single axis, a continuum of "levels." I'd say the axis does not exist, there are no levels, what matters are functions and it is not meaningful to argue whether or not the planarian or the heart is at a higher level of intelligence because the preform different functions. Notably one is a free living creature while another is an organ inside another creater. I think they are incomparable. Neither has the specific brain structure that gives humans and other higher animals sentience so it does not make sense to argue whether one or the other is at a higher level when neither is at any level at all in terms of a structural or functional comparison with a brain. A worm is not further ahead or behind a heart when compared to a brain because neither is anything like a brain. Maybe a plannarian can learn. I doubt a heart can learn but maybe it can. But overall the idea of levels of sentience or sentience simply emerging from complexity that does not intentionally provide for it is silly in my opinion.
That's a very interesting question! (Do we have here some biologist that can try it?)
The difference between an isolated organism and a part is sometimes no so clear. For example in Clonal Colony https://en.wikipedia.org/wiki/Clonal_colony Is each trunk of Pando a different organism? Why not each branch? (Plants do very nasty things to other plants, but in slow motion. It's nice to see time lapses videos of plants "fighting".) Most examples of clonal colonies are plants, some of them have specialized members and some have identical members. If you prefer animals, one nice example is https://en.wikipedia.org/wiki/Portuguese_man_o%27_war
That’s a truly meaty take on the Ship of Theseus[1] problem. In my mind, like so many philosophical problems, the fundamental distinguishing point is materialism vs dualism. For the materialist different matter means different ship. For the dualist the matter is just expressing an ideal. I’ve heard that in Asia there are temples that were totally destroyed and then rebuilt and everyone considers them as old as since their first building date.
My favorite example of this is the planarian. You can cut its head in half and it will generate two new halves. Same with the tail. Or cut the whole thing into pieces, and each piece will regenerate the whole body.
The hydra too. Me and a friend used to pass time doing debates, and when one of us was too tired to research or argue we'd debate about dumb stuff, and I was a stalwart "the original hydra reproduced into two offspring" much like how single celled organisms "die" when they reproduce
And some might say “but the hive itself doesn’t have consciousness, or an ‘experience’”. Which is impossible for you to know, unless you are (or have been) a hive.
This is an example of the greyness that the article discusses. If hives are to be seen as distinct life, it will be quite close to the end of a spectrum.
The "possibility of recovery", as you put it, is a moving target depending on the specific situation and the technology involved. For some examples: https://www.wired.com/2014/07/revive-the-dead/
The point being that as technology continues to develop in this area, our understanding of when someone is "dead" may also continue to shift.
There's also the classic example of comatose people.
That's a good thought - but worth considering that just because lines are fuzzy doesn't make them either 'arbitrary' or even 'subjective'.
That a materialist perspective gives us some nice hard rules for understanding certain things, it also by definition struggles to help us understand the nature of other things, i.e. 'most important bit' which is 'life' itself, so maybe we should be thinking about that problem a little bit differently. 'Emergence' seems to be a least one idea, among many.
For most things in the real life that we categorize, the rules that distinguish those categories can be vague. It doesn't mean those categories are not valid, or a function of 'human perception'.
We have difficulty with biological distinction, but we can still confidently categorize something as being a 'Horse' and 'Not A Horse' ... even if sometimes it's a little bit ambiguous, aka 'Kind of a Horse'.
Edit: and as for 'other ways of thinking' it very quickly goes into metaphysics so it's hard to talk about because we don't spend much time in that realm. 'Emergence' and 'Biocentrism' are interesting ideas (fields?) that sit within more or less regular bounds of science and so they're just examples of what I'm referring to.
I think you'd have to define what it means for a category to be valid. The way I see it is that a category is either useful or not and whether it is or not depends on our goals which depends on what we like and want which is subjective and the judgement itself relative to such a system so designed. That's not to say they are arbitrary, because they're objectively useful or not with respect to the goal.
I don't think biologists would agree with you about the horse. It's actually consider a crisis in the philosophy of biology that the concept of species is ill-defined. [1] Like I said, the resolution to me is pragmatic: the definition will depend on whether it is effective relative to some purpose.
A biologist would only take umbrage rhetorically, which is fine, but they'll never categorize a rock, a flower, or a human as 'a horse' so in reality it's not a problem.
While 'value' is surely in the eye of the beholder ... whether or not something fits into the category is not as subjective.
And frankly, the 'big question' is 'who is the beholder' - which is something that materialism is struggling to tell us.
Why not go further and say the entirety of "our reality" is a human hallucination, as our senses are limited and our brains peculiar in how they process their inputs. That the "real reality" is an imperceptible-to-us dance of fields (even that is only as far as our theories take us).
Lots of loaded words in the comments, and hallucination probably takes some of us to places that aren't helpful, but understanding the limits of our perception and understanding gives us better context. Even if we don't understand the limits, it's helpful to know that our reality and reality are separate things. If we don't know we have blind spots, we won't know to check them.
>"their meaning is inherently embedded in human experience."
Not necessarily, some animals have the same perception. Some carnivores don't eat dead animals, others primarily eat carrion and they interreact differently with inanimate objects.
I think in our lifetimes, we'll know enough about the preconditions for abiogenesis to perform experiments replicating portions of the process in vitro.
We know that it has been a very, very slow process and we don't really know where and under which conditions it happened.
I hope that you are right, that we might be able to replicate portions of it. It might help us understand something more about what we call life. It might also help us understanding alternative forms of life that might exist on other planets.
What makes it fundamentally impossible to know the origin of life? It seems we are likely to develop and refine experiments and theories that approximate the initial conditions and processes by which life took hold. Some of the details of how it happened are certainly lost to time, but it seems there's a lot of room for exploration towards a fairly valid model.
I think they may be arguing semantics of knowing versus believing, and especially the loss of information to the eventual increase of entropy.
I don't think there's a calculation to prove it because it would require a very thorough definition in the first place, which could be taken as a sufficient answer in its own right. The answer is of course 42.
On another note, at "17 hours ago" and no response I guess they are still writing trying to work it out, or gave up, if they are anything like me and my random blurts
You can't ever test anything in the past, so by your logic nothing in the past can be considered scientific. By your logic, plate tectonics can't explain the past movement of continents.
Which is, of course, wrong.
We can absolutely test aspects of a theory, verify its
general validity, see that it best correlates with past evidence, and therefore infer past causes. Nothing of that is unscientific -- to the contrary, that's precisely how science works.
If all we had was observations of modern day plate tectonics it would be foolish to back-propagate the same motions billions of years in reverse and claim ones methods were "scientific".
Luckily, we have things like fossil records to justify such conclusions. They provide the second point with which we can "fit a curve" when exploring history.
With this "origin of life" stuff, we don't have that second point of confirmation. We think up a bizarre process, execute it, and see that it produced some molecules that we see in modern day life. We then have the gall to say that we've discovered "the origins of life"? Yeah right... https://news.ycombinator.com/item?id=27974369
If I may use a programming analogy, the process described is akin to NPC agents in a browser based MMORPG Rowhammering a bunch of random bits into some exposed ArrayBuffer until a Counter div appears on the page, then claiming they have some deeper understanding of the origins of life in their universe.
Do they have a deeper understanding? Perhaps. Have they come anywhere near the "origin of life"? Nope.
I love this animation because it's beautiful, but I hate that it gives the impression of deliberate one-foot-in-front-of-the-other movement. In reality, when the "foot" of the motor protein is unbound, it is oscillating to and fro in a state of brownian motion until it happens to snap into place at the next (or, infrequently but inevitably, the previous) subunit. At this scale, quantum effects such as tunneling come into play, and it would be cool to visualize the organized thermodynamic chaos of the cell rather than the mechanical operation of a homunculus.
Do you truly hate it, or were your feelings oscillating to and fro in an emergent Brownian motion until your feelings snapped into hate instead of love ;)
> quantum effects such as tunneling come into play
Really? I'd not have expected that.
> but I hate that it gives the impression
Oh yes. Rather than being towed, the payload explores its entire tethered configuration space between one step and the next. Not a donkey walking along a river towing a barge, but a mouse clinging to wire and a balloon a hurricane. The nanoscale moshpit from hell.
It's like creating education content about human locomotion, for aliens completely unfamiliar with it, and with no sense of what's plausible, and showing them only one of those stop motion videos where someone floats along not touching the ground. An extremely biased selection of video frames to tell a very false narrative.
Worse, this and other misconceptions engendered might be mitigated by very briefly including other representations... but the folks who created the video explicitly prioritize "pretty" over "do no harm". Which rather diminishes my appreciation of their beauty.
> cool to visualize the organized thermodynamic
Years ago I saw a video at a talk, of simulated viral icosahedral capsid assembly. The panels are tethered together, to maintain proximity, as they bounce and slam together and apart, incrementally assembling and misassembling. I wish I could link to it. If anyone knows of content to give a visceral feel for nanoscale dynamics, I'd appreciate hearing of it.
The meaning of "grayness" would appear to have something to do with the fuzzy line between life and non-life.
There is a footnote to the article "The Seven Pillars of Life":
https://www.pps.net/cms/lib/OR01913224/Centricity/Domain/333...
But it doesn't mention grayness at all.
This gets cleared up a little a few paragraphs in:
> The ability to clearly distinguish between abiotic and biotic systems is considered by many a prerequisite for effective astrobiology studies. However, since no natural demarcation truly exists, there is a profound difficulty in advancing the field if we rely on a strict dichotomy. ...