I'm still interested in any viable theory as to how random chemical processes are able to garner enough information in their own structure to replicate themselves.
That is, Von Neumann showed us that to have a self-replicating automaton we need both the factory and the information for the factory (saved within it). We know that's what a cell is. But how do random chemical processes get there?
Note: time works against chemical processes since the organic chemical compounds decay, keep that in mind when creating a hypothesis.
Note 2: remember that in this case, both the factory & the information gets randomly mutated until you have a factory and information that's complex enough to error correct.
"The prevailing scientific hypothesis is that the transition from non-living to living entities on Earth was not a single event, but a process of increasing complexity involving the formation of a habitable planet, the prebiotic synthesis of organic molecules, molecular self-replication, self-assembly, autocatalysis, and the emergence of cell membranes. Many proposals have been made for different stages of the process."
You can always start your search on matters like this on Wikipedia.
If that's the case on earth then life would be impossible, no? The sun provides constant low entropy energy to the planet that fuels chemical reactions. We see this support life starting at the bottom of the food chain, plants etc, which then supports the rest of life. That works the same way, providing energy for chemical reactions that build things by harvesting the energy. Like plants do, just with simple molecules.
Additionally a lot of energy has been buffered in the rock itself as heat and not quite simple minerals. Underwater heat vents are solid candidates for abiogenesis.
You keep saying that last part and it's meaningless.
The Sun (and sometimes the earth itself) provides energy to the system, and we're talking about a billion years to go from "churning precursors in a hot soup" to "replicating molecular machines".
I mean, what's your alternative theory? The Abrahamic God?
Not really a billion years though. Perhaps several hundred million between when there was liquid water on earth and evidence of bacterial life. A surprisingly short time. We have spend almost 10x as long evolving to modern organisms than it took to get started.
Chemical processes are random because they consist of events that happen when atoms and other things randomly interact with one another as they move around and transition between states.
What would it mean for a chemical process to be "inevitable"? Merely that it has a very high probability of happening?
When we look at the evidence, it seems like life began pretty much as soon as it could have as the earth cooled. It could be that life starting on planets like ours basically just happens as a byproduct of the planet building.
Or, it means that the conditions under which life could arise are not persistent. Life either originated quickly or it would not originate at all. For example, if life originated in a small warm planetesimal, it only had maybe 10 million years before the short lived radioactivity in the early solar system (which we know was there from the decay products) died away and the planetesimals froze.
No, not at all. It was to try to push the discussion toward questioning our ability to predict the probability of life arising. The "random" argument is typically an argument from incredulity, "how could random processes make such a specific thing? The probability is astronomically small." But with only one universe observed, and only one instance of life observed within that one universe, we don't have any way to say that random processes just accidentally formed life vs the probability that it is likely, or even inevitable, that life would form given the properties of the universe.
Adding a god to the discussion doesn't really advance anything at all, honestly. It just explains the mystery with a bigger mystery, so it doesn't explain anything.
Given enough time, even with a random process you will have iterated through every possible result some day. So inevitable here means, it would have to happen at some point, simply because it is possible. So, math.
That highly probable events actually happen can be a reasonable practical assumption, but definitely not a logical certainty.
It is the hard, probabilistic version of the sorites paradox: with few atoms and little time, any chemical process is unlikely; with a whole planet and a few billion years, chemical processes are very likely; at some intermediate sample size you can feel justified to assume that what you are interested in happens, but it is only a feeling, not a real qualitative threshold.
I tried writing code to simulate the "Monkey's typing on a keyboard === Shakespeare" concept.
It was a simple "hello world", and then with only the characters needed for the program. I didn't see it spit out any usable code when I played with it.
But even if it had, it still wasn't able to run without my code existing already... (and the environment I coded it in)
Are you coming at this from a creationist point of view? That's common rhetoric I heard when I was growing up. You'll need to jettison that entire way of thinking, it's built on faulty analogies like "the probability of shuffling a deck of cards into a certain arrangement is astronomically small, therefore evolution couldn't happen!" If you're actually interested in learning and not just sealioning, IMO this is a great resource:
To answer your initial question, it's really difficult to mentally grasp the scales involved with this. Billions of years, quadrillions of watts of power from the sun, some astronomically large number of chemical interactions happening simultaneously all over the early Earth. These numbers throw off one's naive sense of scale. The basic recipe of "hydrogen + time" will produce some very interesting results, however. Eventually we'll reach the heat death of the universe, or some other sort of end[1], but until then all the matter and energy bouncing around will get up to some cool stuff.
Sigh, no. You're asserting that a lot in this thread, but that's not what's happening. In my comment above, I linked to a great learning resource that directly addresses the questions ezrion raised, and is good reading if you're actually curious. Separately, I addressed the likely context in which the question is getting asked, and pointed out that the worldview that starts with creationism is thought-terminating, and should be reassessed as a foundation.
It's great to question any existing consensus. But do so with the intent of learning, not trying to sneak in a religious worldview. If you're going to push a religious agenda, be courteous and at least be up front about it.
No, that's exactly what's happening. Ezrion is asking good questions. Dismissing those questions is not valid science. It's always valid in science to ask "but how do you know?" It is then necessary to accept a good explanation in good faith, though. However, OoL has gaping holes that are currently papered over with handwaving. It's not required to accept handwaving.
Not trying to argue one way or another, but this kinda sounds like trying to reason about rock erosion caused by water by watching a mountain stream flow for 5 minutes.
We have a pretty detailed snapshot of life now, some fossils, and a general understand of biology.
I think you could actually get pretty far at understanding erosion if you had a pretty detailed snapshot of interesting river basins, some landmarks (this rock was over there, etc) and a general understanding of physics.
I think the only necessary ingredient for life is sloppy self-replication. I'd have to look at von Neumann's proof but the theoretical assumptions may not all be valid.
On that note, I'm curious about quasi crystals or crystals prone to substitutions in the lattice. I envision a crystallization process that occurs right on the edge between crystallizing/dissolving. Then any small unit block with some particular contaminant that is slightly more stable becomes favored by evolutionary processes and entropic ones.
If such a thing is possible, and has a sufficiently high upperbound on possible variations, I think you can get a lot of interesting behavior. Over a long period of time, perhaps a crystal unit block could develop that encourages more of its own creation.
It's a fine line though, because usually crystallization doesn't have sufficient complexity to keep evolving, and it's usually driven more by external conditions than by local conditions in the lattice, but nevertheless, it's the most plausible bridge to life I've ever come up with.
Hence why the guess is that it was clays not crystals. Clays are more complex mechanically, somewhat porous, kind of work as a prototype cell wall. Consensus is more on the side of biofilms than crystals at that point. There are relatively simple multiphase processes that can create such lipid and biological bubbles. Just check how micelles form from random hydrocarbons in water with additives. The more stable micelles would allow biofilms to form inside, and so it goes.
Generally cell wall first hypothesis over RNA/peptides first.
Through such a biofilm micelle only certain chemicals can get in or out. This favors particular molecules "crystallizing" (or rather polymerizing) inside such micelles.
> I think the only necessary ingredient for life is sloppy self-replication.
But self-replication has to be very good to be useful. If it makes a mistake 10% of the time, the longest piece of information that be retained is about 10 bits.
It only has to be very good if the things being replicated are very fragile. If you only need 50% accuracy, replication can be very sloppy. And remember, thanks to selection, we can start off sloppy and improve.
How could it only need 50% accuracy? That gives you a genome of 1 bit. That's completely useless and doesn't explain how this process is going to lead to anything with higher accuracy.
There are thousands of examples of proteins that are less than 50% identical, yet fold into exactly the same shapes and catalyze exactly the same chemical reaction. Biological systems are extremely robust to change. And remember, self replicating systems do not only produce one output, they may produce millions. If only one of those million preserves the critical features, things can continue to evolve.
There's vastly more than 1 bit of information in those proteins. If there was just 1 bit, then that would mean that any randomly generated protein would have a 50% chance of having those properties (which is false.)
The question was, how accurate does replication need to be, in a replicating system with selection. My argument is that if you do not need perfect copies, and if you can make large numbers of copies, replication does not need to be very accurate to produce offspring that can continue exhibiting some property that can be selected for.
It seems like your perspective is more information theoretic, and does not include selection.
Yes! I vividly recall the moment when I realized that the emergence of life of earth wasn’t just the lucky occurrence of a cell coming into being, but a cell that could also replicate itself in a non-destructive, information-passing manner. Truly mind boggling stuff. I feel like “time” is often used to obfuscate just how incredible such a development would be, “well if given enough time, then of course we saw a cell that reproduced itself in a sustaining way that actually passed on non-corrupt information while not destroying itself.”
It might just feel that way because it is a boring answer, but boring answers are usually a good sign. We all want the emergence of life to be special, but there’s every reason to believe it was just random. You can fit some pretty unlikely events in (billions of years)*(however many planets). It is really more space, than time, I think, though. I’m actually not sure how many planets there are in the whole universe (not just the observable universe; if we happened to have sprouted up on another planet we’d just be asking this question from inside a different light cone, nothing special about ours).
No, it's a copout. The handwaving about "a long time/many planets" is very weak, when confronted with the complexity barrier between non-living matter and the simplest known system capable of Darwinian evolution. All that time, and all those planets (that we can see in the observable universe), give a number that is very small compared to the unlikelihood of just randomly surmounting this barrier.
Nothing prevents life from originating outside the region we will ever be causally connected to, but life that can never be observed doesn't present much of a handle for conducting science.
As for complexity barrier: consider the number of possible stable configurations with N atoms. It grows exponentially in N. You need to argue either that the chance of a random molecule being alive is high enough (which doesn't seem consistent with the structure we see in life) or that the sampling of these molecular configurations is extremely biased toward some that can start evolution (which is just begging the question.)
> Nothing prevents life from originating outside the region we will ever be causally connected to, but life that can never be observed doesn't present much of a handle for conducting science.
It is a mathematical argument, and not a complicated one, so I’m confused as to how we could be talking past one another here. If we model the chance that abiogenesis occurs on a planet as a random event for that planet, then the probability that it doesn’t occur on any planets is
1 - product(from i=1 to n_planets, 1-P_i), where P_i is the probability that it occurred on the i’th planet. (Sorry for the ugly notation, it is a limitation of basic text, hopefully it makes sense).
These are independent random events, there’s no need to have them linked causally.
> As for complexity barrier: consider the number of possible stable configurations with N atoms. It grows exponentially in N. You need to argue either that the chance of a random molecule being alive is high enough (which doesn't seem consistent with the structure we see in life) or that the sampling of these molecular configurations is extremely biased toward some that can start evolution (which is just begging the question.)
So this seems like an argument from first-principles in chemistry, I don’t know enough about chemistry to say much about it, but I don’t think enumerating every possible configuration of atoms is how they typically do it. I could be wrong though, it is outside my wheelhouse. I would be more comfortable with this argument if it was some well-sourced/well-known thing.
Anyway, this sort of argument seems like it will just shift the individual P_i’s in the equation up or down. We don’t really know enough about abiogenesis to make good estimates there anyway as far as I know, so I don’t see any reason to write off this explanation as a cop-out.
When I mean "causally connected to" I meant "we could send signals to each other". Most of the universe we can currently see is causally disconnected, in that we can never signal them (the nonzero cosmological constant means they will recede faster than a signal could reach them.)
There could be unlimited volumes of spacetime beyond this horizon. Whether life originates there or not we can never know. There is a finite amount of matter within this horizon, and finitely many chances for life to originate. If OoL is sufficiently unlikely it is unlikely to have happened twice in the volume we can reach.
Imagine a molecule that can create identical copies of itself from some other molecules floating around; not by any "factory" but just by "lego mechanics". This is more or less what prions do.
At some point a slightly different molecule appears which is better at converting the molecules, or perhaps they can convert other types of molecules for replication: the first evolutionary step. Perhaps some other mutation allows molecules to "harvest" the other molecules to replicate themselves: the first predators.
Over time this becomes more complex; from singular molecules and proteins to lots of molecules and proteins.
I don't know what Von Neumann "showed us", but IMHO it's not hard to imagine life starting from very simple and humble origins given the enormous timeframes involved (IMO the biggest challenge in understanding these sort of things is understanding just how long a million or 10 million years is, insofar we're even able to do that in the first place).
I feel this is a bad example to use because prions only do so due to the existence of plenty of things as complex as prions. We would need an example that creates more complex structures out of simpler building blocks, not equally complex building blocks.
That's fair, but it's the best example I know of to demonstrate how this could have worked, even though it's not perfect. Happy to hear of other better examples.
The entropy of a perfect crystal approaches zero (at absolute zero). All the positions of the atoms are completely predetermined, so there is no information stored.
You remind me this thing. Those non perfect crystals which are dominant in the real world can have some of the most weirdest behavior in term of quantum chemistry e.g. photo synthesis.
Advanced material science is making use of those crystals to make semi-conductors and stuffs because they can just absorb sunlight and then react with other substances.
You do know that organic chemistry will quickly degrade right? And they have no memory, correct?
So you're telling me that compounds floating around self-assemble into a factory and the information necessary for the factory, including error correcting code, in a short amount of time, randomly?
You're approaching this from a very high-level abstract theoretical point of view; things probably were significantly simpler than you're imagining. There was no "factory" or "information" or anything like that: just basic mechanics on the molecular level. This is still how things like DNA work today, as well as prions as I mentioned before, albeit these are much more complex than earlier life of course.
Perhaps you could detail how organic chemicals without exception degrade rapidly. You may want to share this groundbreaking insight with those that study PFAs, some of which have estimated environmental half-lives of over 1000 years. It's also worth noting that a lot of environmental degradation is caused by the processes of living organisms, which is obviously not an issue if life has not evolved yet.
Additionally there are some theories that rudimentary cell like structures formed in clays, which could protect initial unstable molecules. Then it turned out that adding a biofilm improved the resilience of the barrier.
Even modern RNA and viruses can last for days which is frankly a lot of time. A quick Google indicates you can probably get weeks out of some RNA molecules in reasonable environments.
> I don't know what Von Neumann "showed us", but IMHO it's not hard to imagine life starting from very simple and humble origins given the enormous timeframes involved
It’s not hard to imagine a fire-breathing red dragon or a unicorn either.
What is hard is coming up with an even remotely testable hypothesis for how non-living molecules became alive.
Agreed. But that sounded like creationist dog whistling to me, and I'm curious why OP doesn't want to be explicit about what he thinks. Being explicit usually leads to improving the quality of a discussion IMHO.
Just to respond to your first point, I don't think anyone here is "equating questioning the scientific hypothesis with creationism dogwhistling".
People are calling out Ezion for dogwhistling because of his writing style. Comments written in a glib manner, with superficial counterarguments presented as gotchas, that is suggestive of dogwhistling.
The alternative is that some exponentially unlikely step is needed, which would imply we're not going to see another independent abiogenesis event anywhere in the observable universe.
(replying here because too deeply nested to answer on the comment)
> When did asking "how do we know" become forbidden in science?
What has been forbidden exactly and are you sure we are "in science" here?
> You are exhibiting a deplorable behavior here, equating questioning of a scientific hypothesis with creationism dogwhistling.
Let me sum this up. Asking "how do we know?" with a hidden agenda is OK, but asking "what do you have in mind exactly?" is "deplorable behavior" and should be... "forbidden"?
> Note: time works against chemical processes since the organic chemical compounds decay, keep that in mind when creating a hypothesis.
This caveat does not seems to make sense to me, the advantage of time is that you run the experiment over and over, if one particular run of the experiment fails and then the organic chemicals involved decay, that doesn’t mean time isn’t still on your side.
Also keep in mind that the experiment is run on an absurd number of planets and of we can only be around to ask the question on the planet where it worked out.
My amateur-pop-philosophy-science way of thinking of it is that the transition from low to high entropy creates all kinds of interesting and complicated physical patterns along the way. Enough time, and the right patterns, and self-replication could emerge. But it's the externally driven 'stirring' of the low->high entropy transition that makes this possible.
That is, life exists at the barrier between active and cool energy states. Sun to atmosphere/surface, hot planet core to surface/ocean. It's a (extremely complicated) product of these transitions.
So it's not so much about "how can this just happen by chance" as if you think about what life actually is -- a boundary condition between two entropy states -- it makes more sense: There is a stir stick spinning (solar energy & earth's core) in a very complicated long lasting layered beverage (our earth), and life is the clouds of pretty patterns as the layers mix. The self-replication doesn't happen without that stick being stirred. It's not magic, it's just really complicated.
Biochemist Nick Lane writes quite a bit about the alkaline hydrothermal vent theory and it is very compelling. I don't know (bio)chemistry well enough to fully understand it but it's something like (please people who understand this better correct me...)
a) Very early earth had the 'lucky' combination of active hot core and cool (but not frozen) water covered surface.
b) In addition to 'hot smokers', 'warm' (e.g. closer to cell / body temperature) vents exist and existed on the ocean floor.
c) The ocean water was relatively acidic compared to now. But the warm vents had alkaline chemistry.
d) The specific chemical reactions involved (hand waving here) as the warm vents mixed with the ocean created complex molecules, some organic. And some of the products produced were capsules/bubbles with 'walls' similar in structure cells.
e) There's (more hand waving) reactions that can happen across the walls and molecules produced inside the 'cell-like' things.
f) At some point they 'escape' the vent and its energy source. And in escaping 99.999% of them 'die', but eventually one that escapes does so in a way that it can self-sustain from other energy sources.
g) At the same time at some point those proto-cells develop RNA or RNA-like processes internally such that they can reproduce
It's f->g that I guess is the confusing part for me.
But work is being done in the lab to try reproduce this whole process.
In any case eventually the sun and earth will die, all cell machinery will stop, and entropy will have finally had its way with us. It's not a self-sustaining automaton. It requires an externally driven energy transition.
When the thing is not just simply a molecular but work as a group, that can create some "energy potential" by itself, like attractive to water or nutrition or something. The whole idea of self evolution is not impossible.
They're not actually interested in the answer. It's like asking "If humans evolved from monkeys, why are there still monkeys?!" You explain what a common ancestor is but it doesn't matter because they've already moved on to another bad faith question and aren't listening.
There's real interesting questions to ask here, you're right. They're not getting asked in this thread, though.
This is a convenient excuse for not answering the question. No, science doesn't excuse you if you decide the question wasn't answered in good faith. That's because if your theory cannot answer a question like that, it's a bad theory, regardless of the motivation of the person asking the question.
What's I see here is people defending conventional OoL as a kind of quasi-religion, with dogma that does not need to be experimentally demonstrated and must not be questioned. I treat all religions with disdain, including yours.
This isn't a place to make formal scientific inquiry, and that's not the way to ask scientific questions formally. The way to do that is to write a paper to a journal citing findings that appear to contradict whatever hypothesis is in dispute.
If you ask a question about science to a random person on the Internet they're entirely within their right to say "I don't think you actually want to learn something you don't know, I think you're asking your question to put forward an argument that I've seen many people before you put forward and that I'm tired of hearing, and therefore I'm not going to humor you by answering your question", until you convince them that talking to you isn't a complete waste of time.
Let me make it clear: OoL science has not answered the question of OoL. There are enormous gaping holes in the story. Asking about these holes, or pointing them out, is allowed. Pretending OoL has filled in these holes when it has not, and bullying those who ask the questions, questioning their motives, is not.
First of all, we will probably never know how life originally started, because it was a process at the molecular level that happened billions of years ago. Even if we found a chemical chain that leads to life, we would have no way to know if that particular one is the one that led to current life.
Second, anyone can ask any questions they like and anyone can answer or not any questions they like. No one is obligated to engage with you just because you asked a question. Actually, if someone tells you that they think you're asking your question in bad faith that's a courtesy they're having towards you, because they're giving you the chance to convince them that you're actually being sincere. They could have simply ignored you and gone on with their day.
You're dismissing the scientific process that you claim to support by calling it a "quasi-religion". It's not, you're tilting at windmills, and creationists don't have anything interesting to offer. Here's a great resource when you're ready to learn:
Sorry to be short, but you're doing a very aggressive enlightened centrist bit. Chill out for a bit, and read through the above when you've got some time.
Also, the question was answered in this thread. If you weren't trying to do so much name calling, you'd probably have read the answer and been informed.
Garbage and nonsense, sir. The quasi-religion is claiming certainty when the science has not delivered anything close to it and rejecting attempts to question this false certainty. I see this all too often in OoL and SETI discussions.
Until a synthetic agent will be here we can only guess. The current best guesses seem to have to do with the free energy principle, active inference, Markov blankets [1]. It might be just that simple: it's what happens when some proton gradient reduces ferredoxin [2]. Also related [3].
[1] On-going series of lectures, "Physics as Information Processing" - Chris Fields
[2] "How does chemistry come alive?" - Nick Lane, Alkaline hydrothermal vents at 18:44, https://www.youtube.com/watch?v=QmvS7tgvy6U TL;DW at 52:00 "How does chemistry come alive? It happens when a focused, sustained environmental disequilibrium of H2, CO2, and pH across a porous structure that lowers kinetic barriers to reaction continuously forms organics that bind and self-organize into protocells with protometabolism generating catalytic nucleotides which promote protocell growth through positive feedbacks, favouring physical interactions with amino acids, a nascent genetic code where RNA sequences are selected if they promote protocell growth so genetic information has meaning from the beginning"
Even if the probability for this to succeed is really really small, there's a good chance it will happen when you have billions of years time and idk how many orders of magnitude (10^40? 10^50?) of atoms/molecules constantly interacting.
No, that's not clear at all. The smallest known system capable of independent existence and Darwinian evolution has billions of atoms. A mere 40 or 50 orders of magnitude is trivial compared to the unlikelihood of this arising by chance.
The replies to this comment are zoning in on the epistemological dilemma it poses. Soliciting theories for one of the most difficult scientific puzzles, on HN of all places: do you expect someone to serve you up a neatly-wrapped viable and plausible mechanistic theory?
And yet, I think it’s a serious comment, not a troll, because this is the right epistemic stance. We don’t know how life emerged yet and this is rightly uncomfortable.
As for the object-level topic: I’d direct my attention to any research that investigates the relationship between the cell wall and the inner organelles. I suspect that the viability of the cell factories was dependent on its co-evolution with the cell wall, which, by creating a semi-closed (permeable) system, would change the entropic conditions inside the cell.
We don’t even have a good grasp on what life is! Try to get an explanation of why a living thing is alive, but when it dies despite having the same observable material condition its corpse is not alive. I’ve yet to hear anything beyond the most obvious begging of the question; it’s always some variation on living things are alive because they have life processes and nonliving things aren’t because they don’t. And what’s a life process? Well it’s a process that occurs in living things of course.
I'll take a stab at it: a multicellular organism dies when the processes that are able to sustain the operation of the cell community cease, thus causing the individual cells to die individually or to live as single-celled organisms in the wild for a short while. The main processes that are essential to the life of an organism as a whole are the supply of nutrients and oxygen, the elimination of waste, and the coordination of various support activities between different groups of cells in the body. They're essential because most of the cells have delegated the capacity to perform these functions to the organism, allowing an increase in efficiency at the cost of tying their survival to the survival of the organism.
A cell dies when it's damaged mechanically or chemically, or when it's unable to sustain its metabolism thus causing chemical damage, or when its programming instructs it to destroy itself for whatever reason.
I agree I think the cell is key as its the foundation of the energy dynamics of the cell.
And re: the epistemological questions, etc: I think there's a temptation for people to look for a transcendent, teleological prescription for the 'why' of life; which can range from either 'God' to some abstract 'progress' concept where nature proceeds to 'higher stages' etc (panspermia, gaia, whatever). It's deeply part of at least western culture since at least Aristotle and Plato to use these kinds of tools.
But I believe the 'answer' here is just a big messy 'immanent' one rather than any transcendent order. Life happened as it happened because it happened... and it will unhappen someday, too.
And of course we would not be here to ask questions about it if it hadn't, so is it really a puzzle that needs a formula to answer it?
Humans look for "reasons" for things because that's a useful conceptual tool for understanding why other people in our kin groups do things, or why a herd of gazelle we're hunting is in a particular place, or why a plant we harvest from didn't grow well this year.
But there's no reason to assume that this conceptual tool makes any sense for understanding "life" or "existence." It's a crude instrument. At that level, there is no "why", there is only "is".
(And I'd posit further we should not make assumptions like "oh it happened here [us] so it must have happened elsewhere because <xxxx principle / transcendent order / natural progression> ... so ... Star Trek!"; the universe is massive, yes, but that doesn't mean the precise events duplicate multiple times and it does seem like complex multicellular life was a kind of ... fluke ...)
>Note: time works against chemical processes since the organic chemical compounds decay, keep that in mind when creating a hypothesis.
The question is how quickly do they decay in a sterile environment. A virus which has no active mechanism for preventing decay can last for days. RNA can have half lives measured in days. That's a lot of time and I'm sure there's more stable variants but in modern times stability is not a prime concern for organic molecules.
Life didn't start as cells. It started as "naked" self-replicating molecules with no supporting infrastructure. Think a virus without its protective protein coat. Cells only came along much later, because they are much harder to evolve.
We already know that an energy input, such as solar energy, to a large collection of simple molecules like methane and ammonia can produce the building blocks of life: amino acids and nucleotides. Once a short chain of nucleotides is formed, it will (slowly) replicate itself by attracting other nucleotides in the environment. That's all the original "life" on Earth consisted of. The simple chains of nucleotides were both "factory" and "information".
We don't know all the specific steps that life took between those first simple replicators and cells. We may never know for sure because data left over from that time is so sparse. But that's not the same as not having a viable theory. We have that.
That's a good story, but is there any evidence for it?
We know simple building blocks can be created, in low concentrations, with large amounts of other components that don't end up in life. The concentration of any given chemical in this mix is exponentially dependent on its complexity. The "once a short chain is formed, it will (slowly) replicate" is entirely unsupported by experiment. Indeed, it's difficult to see how it could work, when it's replicating in a soup loaded with junk monomers.
I think Von Neumann suggested what might be needed to engineer a complex self-replicating system. He didn't suggest a process that might incrementally lead to that though (abiogenesis in the case of biological life), which might be able to rely on simple chemical behaviors to start accumulating complexity.
If it is random, and the universe is infinite, as we assume it to be, it will happen somewhere, an infinity of times, no matter how unlikely the event is. There should be exact copies of you popping into existence somewhere from quantum fluctuations alone.
Current studies are about finding the most likely pathway, rather than knowing whether of not it is possible. We know it is possible because we are here.
> But how do random chemical processes [make the leap from molecules to cells]?
Ya, that's a kicker.
Another mind bender for me is the concept of "self". When some collection starts to prefer their own company over others. That boundary (or barrier or affinity or homophily or whatever) between "me" and "not me".
Chemical processes are not random, at least not in the way you're using the word. When you mix a base and an acid it's not subject to a roll of the dice whether they will neutralize or not. If you pour oil into water there's not a small chance that this one time they will dissolve into each other.
>We know that's what a cell is. But how do random chemical processes get there?
Work backwards. Think of the simplest cell you can. Now remove the membrane and the little molecular machines are free to wander in the medium arbitrarily far away from each other. The chemical processes are still happening, but they just take a long time to finish. All you need is for the abiotic medium to contain at least one of every of those molecules to have a sort of diffuse protolife.
The same way Christianity and Islam became prevalent. Pre-scientific people made up many stories about the universe. The ones that spread the farthest are the ones that replicate, by killing and converting opposition like these religions have. Similarly, many compounds have randomly formed that exhibit parts of what we call life. The ones that exist in noticeable quantities are the ones that successfully replicate.
"Life === multi-cellular organisms" is also a rather antiquated take on the matter. This headline is misleading. In fact we don't even have a solid definition of "life", which leads to multivarious hypotheses on how the various stages arose.
The subject of the article itself is interesting, I just wish science writers were more precise in their language to reflect the precision and specificity of the scientific hypotheses being explored.
I’m guessing that he’s asking that they write down/define the definition explicitly that they’re using in articles like this so we have some idea what they’re advocating for or testing/exploring exactly.
I was about to complain on the title too. They say that a theory is being challenged on how life on earth started and then all of a sudden in the first 2 paragraphs jump a couple million (if not billion) years straight to multicellular organisms.
I didn't read any more, I do hope they started discussing how multicellularity arose and only the title was amiss.
Consider the authors of papers and studies don't write the articles and headlines. The headline is written as a click-hook, to get PR, because, well "publish or perish" and that's how the funding comes in.
It sucks, but also if you just published the paper with a dry summary, it would also get ignored.
Also, the bias is old. "Eukaryote" means "true cell"! It's right in the name, this bias about what "real" life is. Of course it's our anthropocentrism, I guess, but...
I also think, on the broader point about abiogensis... it's quite likely that the cosmos is rather full of things that look like our prokaryotes. But eukaryotes and complicated multicellular life is either going to be extremely rare or non-existent within anything observable in, say, our galaxy. I say this because prokaryotes arose almost as soon as the earth cooled and developed a liquid ocean, and have been here almost as long as the planet.
But eukaryotes have only been here for maybe 15% of the planet's existence or less, and seem to have basically arisen as kind of a 'fluke' event, and only once, and seem to have something to do with the very particulars of cell energy dynamics, mitochondria, and the fusion of archaeobacteria and bacteria, etc. Just really weird stuff.
Putting it yet another way... prokaryotes have existed for almost the entire life of our planet, compose most of the life and biomass of the planet, and shape it in its most fundamental ways but are much the same as when they started, because they have rather strong intrinsic physical limits on energy and complexity.
So, yes, life != multicellular organisms, but maybe it might turn out that eukaryotic and/or multicellular life is the only real "interesting" kind of life from the most broad perspective.
The concern is that "origins of life" is a distinct issue from "origins of multicellularity". You rightly point out that origins of life per se is of more cosmological/physical significance, whereas multicellularity is primarily (exo-)biological in nature.
However I vehemently disagree that multicellularity is the "only interesting kind of life". We don't even know yet if life of computational origin exists so as to be able to call it life per se. We don't know lots of things. It's just hubris to act as if we have enough information to make such strong claims.
Sidenote I think it is refreshing that there seems to be so much collaboration between Lund in Sweden and Danish institutions like this. This is the third time a Danish paper on HN mentions Lund. I have no insight in why it is like that.
Thanks to the bridge between the countries, it's only like a one hour car ride between the two universities. Both of them are also part of the region Øresund/Öresund which has lots of collaboration between the two countries, because of the proximity between the two. Jokingly called "Greater Copenhagen Region" sometimes as the pull on the region from Copenhagen is stronger than the pull from the Swedish counterpart Stockholm.
Many textbooks and scientific resources describe phenomena from hundreds of millions of years ago as "indisputable facts", this include everything from the origins of life on earth, to the big bang theory, what happens in black holes, formation of the solar system and galaxy, how geology has evolved and many more. Additionally they make pseudoscientific predictions about exactly when and what will happen millions of years in the future. For instance the sun will turn into a red giant in "approximately 5 billion years". I don't know why they try to pass off so many theories as facts, probably a bunch of science politics combined with hubris and unwillingness to admit what we don't know.
Because we have theories and proofs for those theories. Others like "god created the world" or something have nothing to support them. Therefore those are currently being viewed as facts as long as there is no alternative theory and proof.
You can't say that "but we will find disproving material in the future so this is not fact". If this kind of argument is valid, I can also say that "you will be wrong anyway in the future so you are just wrong all the time". Do not use future to determine today.
Since you're obviously such an expert in all these fields that you can confidently assert that none of them know what they're talking about, why don't you link to some of your published papers where you prove that the accepted theories and analyses are wrong?
If you're going to insult and denigrate entire fields of research, I think you should put your money where your mouth is.
Stellar lifecycle models are based on a combination of theoretical physics, experimental physics results that set bounds on (in a way) the theoretical predictions, and mathematical modeling - all of which is also validated through observational physics of stars that are, actually, at the red giant stage, and sampling stars at the intermediary stages - based on actual observations.
Armed with all of this data, and working on an assumption that current ‘laws’ of physics will continue to apply in the future, scientists can make reasonably confident predictions.
Similar approach, though admittedly with far less mathematical modeling, is also the case in biology.
Even textbooks and scientific resources have to assume, at some point, that we start with a framework of axioms.
But most science textbooks also first introduce the idea of models, hypothesis and the notion that a ‘law’, is only as good as the most recent experiment that supports it - and that the scientific method requires us to discard or amend the ‘law’ if new evidence contradicts its predictions. To keep repeating this foundational idea every step of the way seems tedious - it’s reasonable to treat gravity on earth as a fact in the face of overwhelming observational evidence, for instance.
I don’t see how any of this reflects hubris and unwillingness to admit what we don’t know.
For instance, as an (ex-)biologist, I completely agree we do not have a good model for consciousness; or that we simply don’t have a solid functional model of a cell that allows us to model and predict its behaviour at detail and with all its complexity - we are still, in fact, discovering layers of complexity and nuance. But there are some things we do understand well.
Same in physics - the search for a Grand Unifiying Theory continues. ‘Dark matter’, as I understand it, is an acknowledged proxy for many things we don’t yet understand.
i believe in science, i just think sometimes it goes a little too far with what it claims to know as fact
if we knew all the secrets of the universe we wouldn't be stuck on this rock and dying every 80 years
you have to admit there's some dissonance between claiming to know the fine details of the ancient origins of the universe and struggling to predict if it will rain next week
Much of what the “scientific” (being indeed pseudo-scientific in many ways) textbooks that we see from the young age present as fact are what is merely metaphors used in current physical models or predictions of those models—not at all statements of some absolute ground truth, yet presented as such.
Of course, there is more than one model, all of them evolve all the time, none of them are perfect (the map is never the territory), and none of them concern themselves with philosophy (a.k.a. unfalsifiable statements about what is “real reality” and the like).
This misrepresentation leads to all sorts of confusion (the quintessential example being light as waves vs. particles), physicalism-by-default (along with illusionism and determinism) as mainstream philosophical worldview among the STEM crowd, and perhaps even distrust to natural sciences among some others.
I blame it on the age-old patriarchal desire to appear a knowledgeable, reputable and indisputable authority to young students, and I’d wager that such people self-select for the job of writing and vetting textbooks.
Any decent science curriculum will cover the inherent mutability of scientific knowledge, the fact that it is just a model that is updated as we add knowledge—these facts and the process of updating the model are the main takeaways of the scientific method. If you weren’t exposed to that sort of stuff, that’s a substantial strike against somewhere’s education system.
While I somewhat agree that all too often science reporting, especially in "pop science" type rags, reporting tends to often pass off theory and speculation as fact. I think the issue in schools is less to do with textbooks and more to do with teachers failing to properly convey what science is supposed to be, instead turning it into the same drab memorization and regurgitation. It's just the same issue that's plaguing teaching in other subjects.
Plus, in some cases, especially for younger students, the truth is twisted (even if to the point of being wrong) because the real answer would be a bit beyond their ability to understand. For example, explaining atomic structure as if electrons are just balls spinning around a nucleus or describing light as simple rays.
They're very wrong, but convey enough information to build some other concepts on before the students are able to understand the truth.
The Big Bang is indisputable, in the sense that there's no other model that can generate the CMBR except having the universe in the past be very dense and hot.
I am surprised by how many commenters seem to be anti-scientific comments or crypto-creationist arguments.
This is one study covering a form of life that was largely replaced during the Cambrian explosion, and took place right after massive glaciation , while the environment was very different to today, or even the Cambrian epoch.
The main point of the study is that Oxygen levels may have been lower than thought, which isn't "a problem for science" because "science" isn't even sure if the many fossils from that period were animals (and would require higher oxygen levels).
And for people here who didn't read the article: this isn't about the origins of _cellular_ life, or even multicellular life. Multicellular life had been around for tens of millions of years. And life itself had been around for billions.
This study asks "are we wrong about how much O2 COMPLEX life requires?" And we may be, Because the ediacaran had different life forms than we have now after the Cambrian explosion.
Which commenters are you referring to? You piqued my interest but nobody said stuff like “a problem for science” as far as I can tell. EDIT: this wasnt meant as a jab. I’m not well read in this topic so it’s hard for me to detect the “crypto creationists”.
I've been noticing a lot of Christians on HN lately. I'm not saying it's a coordinated effort, but I've seen more in the past 2 weeks than I've seen in the past decade.
I usually lurk, then make an account with a random password if the urge to comment comes upon me. I'll use the account until I clear my cookies and repeat the whole process. Part of this is to dodge textual analysis by ML, part of it is because I don't like feeling too attached.
I came here from that event, but I’m your stereotypical left-wing atheist redditor. I guess the site is pretty heavily sectioned off, but I assumed that was the bulk of us.
Editing to add: this site has been so much better for my mental health. Still plenty of bad news about the environment and large corporations, etc. but I focus less on it, and much more on topics that rekindle my passion for science and technology.
Not OP, but this chap [1] retraces the early stages of Kant’s thoughts on mathematics [2]. (The commenter concludes it’s all made up because it’s difficult to think about. Fortunately, Kant went further, though he, too, ultimately deus ex machina’d the ending.)
Not really a good sign. There's legitimate arguments to have, and then there's creationism, 5g causes covid, q-anon, etc that lower the quality of discussion because the people posting about that aren't actually interested in discussion.
Math is immaterial so science is fake isn’t a novel perspective [1], it’s literally 17th-century material and a symptom of America’s lack of philosophical education.
Is it? I think it's a symptom of lack of science and math education. No one who understands both of them would think that either is proof that the other one is "fake".
Independently minded is great. Refusing to accept reality isn't something that's conducive to an interesting discussion, and I'm happy to have that filtered out.
Where "reality" is defined as "that part of reality which is deemed acceptable at this moment", otherwise known as the Overton window. Mention something which lies outside of it but still well within the domain of science - I'm not talking about creationism - and you'll soon find out "reality" deserves those scare quotes around it. Go have a look at the discussions around SARS2, around the efficacy or lack thereof of the experimental vaccines or whether masking really provides protection against these types of infections. There is legitimate science on both sides of the debate but only one side was welcome during the pandemic, those who cited the other side quickly got labelled and nullified. There are countless other areas where this phenomenon can be seen and where a label and nullification awaits those who dare to step over the line, I'm fairly sure everyone can think of a few of them.
> I am surprised by how many commenters seem to be anti-scientific comments or crypto-creationist arguments.
You must have a hair-trigger definition of anti-scientific cryptocreationist because I don't see it.
IMO, drawing narrow boundaries around how scientific questions can be discussed is rather anti-scientific, since a search for the truth can't presuppose that truth.
Nah, you get used to spotting people sealioning and JAQing off. In this thread, ezion is likely a creationist of some sort and is asking either bad faith or ignorant questions. I recognize where those questions are coming from, having grown up religious.
It's great to ask questions about evolution if you're a creationist and you're trying to learn. It gets tiring to recognize that someone is looking to do a gotcha and ignore the explanation of why it's not a gotcha.
You're misquoting the OP, "surprised at how many" can simply mean any existing at all, depending on one's expectations. More to the point though, this isn't "drawing narrow boundaries around how scientific questions can be discussed" or anything of the sort. It's recognizing some of the comments for what they are: bad faith attempts at pushing a religious agenda.
I accurately quoted the OP, which you must be able to see for yourself.
If OP meant "that one guy" instead of "many", they could always edit/reply to clarify. For my part, I can only respond to the ideas actually expressed.
Maybe it's all determinism and noise, except for humans. Humans get intelligence.
Or maybe it's intelligence all the way down. A thousand different shapes and sizes of memory, logic, communication, etc. All the way down to cells and beyond.
This comment makes zero sense whatsoever… in the small small chance this was posted by an actually misguided person rather for reactions:
Without humans the moon still would have existed, bound by gravity in an orbit that can be described by what is called math. Discovering and naming a concept does not mean creating it. Antarctica was not created by the person who saw and named it, neither did the first person to try to measure the circumference of a circle decide that it should be 3.14 times the diameter. Whether or not it was measured and named it would still be the same ratio.
Judging from the timeline though going from eukaryotes to procaryotes is weirdly just as tricky if not more so. I mean - eukaryotes showed up after life had been on earth for 1 - 1.5 billion years. Procaryotes showed up almost right after the Earth could conceivably supported life at all.
That's always struck me as really weird. It also makes me think if we ever find alien life we're probably going to be disappointed.
178 comments
[ 2.5 ms ] story [ 255 ms ] threadThat is, Von Neumann showed us that to have a self-replicating automaton we need both the factory and the information for the factory (saved within it). We know that's what a cell is. But how do random chemical processes get there?
Note: time works against chemical processes since the organic chemical compounds decay, keep that in mind when creating a hypothesis.
Note 2: remember that in this case, both the factory & the information gets randomly mutated until you have a factory and information that's complex enough to error correct.
While the original factory is not self-replicating, if you reached a fix point you would get a self-replicating factory
"The prevailing scientific hypothesis is that the transition from non-living to living entities on Earth was not a single event, but a process of increasing complexity involving the formation of a habitable planet, the prebiotic synthesis of organic molecules, molecular self-replication, self-assembly, autocatalysis, and the emergence of cell membranes. Many proposals have been made for different stages of the process."
You can always start your search on matters like this on Wikipedia.
There's no evidence for the above: chemical processes decay, time works against the chemistry.
The Sun (and sometimes the earth itself) provides energy to the system, and we're talking about a billion years to go from "churning precursors in a hot soup" to "replicating molecular machines".
I mean, what's your alternative theory? The Abrahamic God?
It is fascinating how early "goop to replicators" happened in our history. It really highlights how common life must be where there's water.
You're begging the question here. How do you know it was random and not inevitable?
What would it mean for a chemical process to be "inevitable"? Merely that it has a very high probability of happening?
When we look at the evidence, it seems like life began pretty much as soon as it could have as the earth cooled. It could be that life starting on planets like ours basically just happens as a byproduct of the planet building.
Adding a god to the discussion doesn't really advance anything at all, honestly. It just explains the mystery with a bigger mystery, so it doesn't explain anything.
It was a simple "hello world", and then with only the characters needed for the program. I didn't see it spit out any usable code when I played with it.
But even if it had, it still wasn't able to run without my code existing already... (and the environment I coded it in)
That's what needs to be done to achieve what was achieved.
https://www.talkorigins.org/indexcc/
There's a section specifically on abiogenesis: https://www.talkorigins.org/indexcc/list.html#CB0
To answer your initial question, it's really difficult to mentally grasp the scales involved with this. Billions of years, quadrillions of watts of power from the sun, some astronomically large number of chemical interactions happening simultaneously all over the early Earth. These numbers throw off one's naive sense of scale. The basic recipe of "hydrogen + time" will produce some very interesting results, however. Eventually we'll reach the heat death of the universe, or some other sort of end[1], but until then all the matter and energy bouncing around will get up to some cool stuff.
[1]: Good reading here: https://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe
It's great to question any existing consensus. But do so with the intent of learning, not trying to sneak in a religious worldview. If you're going to push a religious agenda, be courteous and at least be up front about it.
I think you could actually get pretty far at understanding erosion if you had a pretty detailed snapshot of interesting river basins, some landmarks (this rock was over there, etc) and a general understanding of physics.
On that note, I'm curious about quasi crystals or crystals prone to substitutions in the lattice. I envision a crystallization process that occurs right on the edge between crystallizing/dissolving. Then any small unit block with some particular contaminant that is slightly more stable becomes favored by evolutionary processes and entropic ones.
If such a thing is possible, and has a sufficiently high upperbound on possible variations, I think you can get a lot of interesting behavior. Over a long period of time, perhaps a crystal unit block could develop that encourages more of its own creation.
It's a fine line though, because usually crystallization doesn't have sufficient complexity to keep evolving, and it's usually driven more by external conditions than by local conditions in the lattice, but nevertheless, it's the most plausible bridge to life I've ever come up with.
Generally cell wall first hypothesis over RNA/peptides first.
Through such a biofilm micelle only certain chemicals can get in or out. This favors particular molecules "crystallizing" (or rather polymerizing) inside such micelles.
I've always felt that RNA was probably a very late addition to the game of life.
But self-replication has to be very good to be useful. If it makes a mistake 10% of the time, the longest piece of information that be retained is about 10 bits.
It seems like your perspective is more information theoretic, and does not include selection.
I don’t see any reason to limit things to the observable universe. What prevents life from emerging outside of our light cone?
As for complexity barrier: consider the number of possible stable configurations with N atoms. It grows exponentially in N. You need to argue either that the chance of a random molecule being alive is high enough (which doesn't seem consistent with the structure we see in life) or that the sampling of these molecular configurations is extremely biased toward some that can start evolution (which is just begging the question.)
It is a mathematical argument, and not a complicated one, so I’m confused as to how we could be talking past one another here. If we model the chance that abiogenesis occurs on a planet as a random event for that planet, then the probability that it doesn’t occur on any planets is
1 - product(from i=1 to n_planets, 1-P_i), where P_i is the probability that it occurred on the i’th planet. (Sorry for the ugly notation, it is a limitation of basic text, hopefully it makes sense).
These are independent random events, there’s no need to have them linked causally.
> As for complexity barrier: consider the number of possible stable configurations with N atoms. It grows exponentially in N. You need to argue either that the chance of a random molecule being alive is high enough (which doesn't seem consistent with the structure we see in life) or that the sampling of these molecular configurations is extremely biased toward some that can start evolution (which is just begging the question.)
So this seems like an argument from first-principles in chemistry, I don’t know enough about chemistry to say much about it, but I don’t think enumerating every possible configuration of atoms is how they typically do it. I could be wrong though, it is outside my wheelhouse. I would be more comfortable with this argument if it was some well-sourced/well-known thing.
Anyway, this sort of argument seems like it will just shift the individual P_i’s in the equation up or down. We don’t really know enough about abiogenesis to make good estimates there anyway as far as I know, so I don’t see any reason to write off this explanation as a cop-out.
There could be unlimited volumes of spacetime beyond this horizon. Whether life originates there or not we can never know. There is a finite amount of matter within this horizon, and finitely many chances for life to originate. If OoL is sufficiently unlikely it is unlikely to have happened twice in the volume we can reach.
At some point a slightly different molecule appears which is better at converting the molecules, or perhaps they can convert other types of molecules for replication: the first evolutionary step. Perhaps some other mutation allows molecules to "harvest" the other molecules to replicate themselves: the first predators.
Over time this becomes more complex; from singular molecules and proteins to lots of molecules and proteins.
I don't know what Von Neumann "showed us", but IMHO it's not hard to imagine life starting from very simple and humble origins given the enormous timeframes involved (IMO the biggest challenge in understanding these sort of things is understanding just how long a million or 10 million years is, insofar we're even able to do that in the first place).
I feel this is a bad example to use because prions only do so due to the existence of plenty of things as complex as prions. We would need an example that creates more complex structures out of simpler building blocks, not equally complex building blocks.
I would say solid state is more complex than fluid.
Advanced material science is making use of those crystals to make semi-conductors and stuffs because they can just absorb sunlight and then react with other substances.
So you're telling me that compounds floating around self-assemble into a factory and the information necessary for the factory, including error correcting code, in a short amount of time, randomly?
I don't think you've thought this through.
Cell wall is a really amazing thing.
I'm not sure if I would count days (or possibly weeks) as quick.
It’s not hard to imagine a fire-breathing red dragon or a unicorn either.
What is hard is coming up with an even remotely testable hypothesis for how non-living molecules became alive.
When did asking "how do we know" become forbidden in science? Convention OoL is looking entirely too dogmatic and religious for my taste.
People are calling out Ezion for dogwhistling because of his writing style. Comments written in a glib manner, with superficial counterarguments presented as gotchas, that is suggestive of dogwhistling.
> When did asking "how do we know" become forbidden in science?
What has been forbidden exactly and are you sure we are "in science" here?
> You are exhibiting a deplorable behavior here, equating questioning of a scientific hypothesis with creationism dogwhistling.
Let me sum this up. Asking "how do we know?" with a hidden agenda is OK, but asking "what do you have in mind exactly?" is "deplorable behavior" and should be... "forbidden"?
OK, troll, bye bye.
This caveat does not seems to make sense to me, the advantage of time is that you run the experiment over and over, if one particular run of the experiment fails and then the organic chemicals involved decay, that doesn’t mean time isn’t still on your side.
Also keep in mind that the experiment is run on an absurd number of planets and of we can only be around to ask the question on the planet where it worked out.
That is, life exists at the barrier between active and cool energy states. Sun to atmosphere/surface, hot planet core to surface/ocean. It's a (extremely complicated) product of these transitions.
So it's not so much about "how can this just happen by chance" as if you think about what life actually is -- a boundary condition between two entropy states -- it makes more sense: There is a stir stick spinning (solar energy & earth's core) in a very complicated long lasting layered beverage (our earth), and life is the clouds of pretty patterns as the layers mix. The self-replication doesn't happen without that stick being stirred. It's not magic, it's just really complicated.
Biochemist Nick Lane writes quite a bit about the alkaline hydrothermal vent theory and it is very compelling. I don't know (bio)chemistry well enough to fully understand it but it's something like (please people who understand this better correct me...)
a) Very early earth had the 'lucky' combination of active hot core and cool (but not frozen) water covered surface.
b) In addition to 'hot smokers', 'warm' (e.g. closer to cell / body temperature) vents exist and existed on the ocean floor.
c) The ocean water was relatively acidic compared to now. But the warm vents had alkaline chemistry.
d) The specific chemical reactions involved (hand waving here) as the warm vents mixed with the ocean created complex molecules, some organic. And some of the products produced were capsules/bubbles with 'walls' similar in structure cells.
e) There's (more hand waving) reactions that can happen across the walls and molecules produced inside the 'cell-like' things.
f) At some point they 'escape' the vent and its energy source. And in escaping 99.999% of them 'die', but eventually one that escapes does so in a way that it can self-sustain from other energy sources.
g) At the same time at some point those proto-cells develop RNA or RNA-like processes internally such that they can reproduce
It's f->g that I guess is the confusing part for me.
But work is being done in the lab to try reproduce this whole process.
In any case eventually the sun and earth will die, all cell machinery will stop, and entropy will have finally had its way with us. It's not a self-sustaining automaton. It requires an externally driven energy transition.
There's real interesting questions to ask here, you're right. They're not getting asked in this thread, though.
What's I see here is people defending conventional OoL as a kind of quasi-religion, with dogma that does not need to be experimentally demonstrated and must not be questioned. I treat all religions with disdain, including yours.
If you ask a question about science to a random person on the Internet they're entirely within their right to say "I don't think you actually want to learn something you don't know, I think you're asking your question to put forward an argument that I've seen many people before you put forward and that I'm tired of hearing, and therefore I'm not going to humor you by answering your question", until you convince them that talking to you isn't a complete waste of time.
Second, anyone can ask any questions they like and anyone can answer or not any questions they like. No one is obligated to engage with you just because you asked a question. Actually, if someone tells you that they think you're asking your question in bad faith that's a courtesy they're having towards you, because they're giving you the chance to convince them that you're actually being sincere. They could have simply ignored you and gone on with their day.
https://www.talkorigins.org/indexcc/
Sorry to be short, but you're doing a very aggressive enlightened centrist bit. Chill out for a bit, and read through the above when you've got some time.
Also, the question was answered in this thread. If you weren't trying to do so much name calling, you'd probably have read the answer and been informed.
[1] On-going series of lectures, "Physics as Information Processing" - Chris Fields
Lecture 1 - https://www.youtube.com/watch?v=RpOrRw4EhTo
Lecture 2 - https://www.youtube.com/watch?v=WkWIqpxWRM4
Lecture 3 - https://www.youtube.com/watch?v=TOZp_XNYijQ
[2] "How does chemistry come alive?" - Nick Lane, Alkaline hydrothermal vents at 18:44, https://www.youtube.com/watch?v=QmvS7tgvy6U TL;DW at 52:00 "How does chemistry come alive? It happens when a focused, sustained environmental disequilibrium of H2, CO2, and pH across a porous structure that lowers kinetic barriers to reaction continuously forms organics that bind and self-organize into protocells with protometabolism generating catalytic nucleotides which promote protocell growth through positive feedbacks, favouring physical interactions with amino acids, a nascent genetic code where RNA sequences are selected if they promote protocell growth so genetic information has meaning from the beginning"
[3] "Origins of the RNA-Protein World – Lost in Translation?" - John Sutherland, https://www.youtube.com/watch?v=bSjIDStlZg8
And yet, I think it’s a serious comment, not a troll, because this is the right epistemic stance. We don’t know how life emerged yet and this is rightly uncomfortable.
As for the object-level topic: I’d direct my attention to any research that investigates the relationship between the cell wall and the inner organelles. I suspect that the viability of the cell factories was dependent on its co-evolution with the cell wall, which, by creating a semi-closed (permeable) system, would change the entropic conditions inside the cell.
A cell dies when it's damaged mechanically or chemically, or when it's unable to sustain its metabolism thus causing chemical damage, or when its programming instructs it to destroy itself for whatever reason.
And re: the epistemological questions, etc: I think there's a temptation for people to look for a transcendent, teleological prescription for the 'why' of life; which can range from either 'God' to some abstract 'progress' concept where nature proceeds to 'higher stages' etc (panspermia, gaia, whatever). It's deeply part of at least western culture since at least Aristotle and Plato to use these kinds of tools.
But I believe the 'answer' here is just a big messy 'immanent' one rather than any transcendent order. Life happened as it happened because it happened... and it will unhappen someday, too.
And of course we would not be here to ask questions about it if it hadn't, so is it really a puzzle that needs a formula to answer it?
Humans look for "reasons" for things because that's a useful conceptual tool for understanding why other people in our kin groups do things, or why a herd of gazelle we're hunting is in a particular place, or why a plant we harvest from didn't grow well this year.
But there's no reason to assume that this conceptual tool makes any sense for understanding "life" or "existence." It's a crude instrument. At that level, there is no "why", there is only "is".
(And I'd posit further we should not make assumptions like "oh it happened here [us] so it must have happened elsewhere because <xxxx principle / transcendent order / natural progression> ... so ... Star Trek!"; the universe is massive, yes, but that doesn't mean the precise events duplicate multiple times and it does seem like complex multicellular life was a kind of ... fluke ...)
The question is how quickly do they decay in a sterile environment. A virus which has no active mechanism for preventing decay can last for days. RNA can have half lives measured in days. That's a lot of time and I'm sure there's more stable variants but in modern times stability is not a prime concern for organic molecules.
Nobel laureate Jack Szostak from University of Chicago delivered the Eyring General Lecture on March 17, 2023 at Arizona State University.
"The Origin of Life: Not as Hard as it Looks?"
https://www.youtube.com/watch?v=ZLzyco3Q_Rg
We already know that an energy input, such as solar energy, to a large collection of simple molecules like methane and ammonia can produce the building blocks of life: amino acids and nucleotides. Once a short chain of nucleotides is formed, it will (slowly) replicate itself by attracting other nucleotides in the environment. That's all the original "life" on Earth consisted of. The simple chains of nucleotides were both "factory" and "information".
We don't know all the specific steps that life took between those first simple replicators and cells. We may never know for sure because data left over from that time is so sparse. But that's not the same as not having a viable theory. We have that.
We know simple building blocks can be created, in low concentrations, with large amounts of other components that don't end up in life. The concentration of any given chemical in this mix is exponentially dependent on its complexity. The "once a short chain is formed, it will (slowly) replicate" is entirely unsupported by experiment. Indeed, it's difficult to see how it could work, when it's replicating in a soup loaded with junk monomers.
Current studies are about finding the most likely pathway, rather than knowing whether of not it is possible. We know it is possible because we are here.
As for the technical details, look up "abiogenesis" ( https://en.wikipedia.org/wiki/Abiogenesis )
"Garner" is perfect here, thank you.
> But how do random chemical processes [make the leap from molecules to cells]?
Ya, that's a kicker.
Another mind bender for me is the concept of "self". When some collection starts to prefer their own company over others. That boundary (or barrier or affinity or homophily or whatever) between "me" and "not me".
>We know that's what a cell is. But how do random chemical processes get there?
Work backwards. Think of the simplest cell you can. Now remove the membrane and the little molecular machines are free to wander in the medium arbitrarily far away from each other. The chemical processes are still happening, but they just take a long time to finish. All you need is for the abiotic medium to contain at least one of every of those molecules to have a sort of diffuse protolife.
[0]: https://arxiv.org/ftp/arxiv/papers/1304/1304.3381.pdf
The subject of the article itself is interesting, I just wish science writers were more precise in their language to reflect the precision and specificity of the scientific hypotheses being explored.
I didn't read any more, I do hope they started discussing how multicellularity arose and only the title was amiss.
It sucks, but also if you just published the paper with a dry summary, it would also get ignored.
Also, the bias is old. "Eukaryote" means "true cell"! It's right in the name, this bias about what "real" life is. Of course it's our anthropocentrism, I guess, but...
I also think, on the broader point about abiogensis... it's quite likely that the cosmos is rather full of things that look like our prokaryotes. But eukaryotes and complicated multicellular life is either going to be extremely rare or non-existent within anything observable in, say, our galaxy. I say this because prokaryotes arose almost as soon as the earth cooled and developed a liquid ocean, and have been here almost as long as the planet.
But eukaryotes have only been here for maybe 15% of the planet's existence or less, and seem to have basically arisen as kind of a 'fluke' event, and only once, and seem to have something to do with the very particulars of cell energy dynamics, mitochondria, and the fusion of archaeobacteria and bacteria, etc. Just really weird stuff.
Putting it yet another way... prokaryotes have existed for almost the entire life of our planet, compose most of the life and biomass of the planet, and shape it in its most fundamental ways but are much the same as when they started, because they have rather strong intrinsic physical limits on energy and complexity.
So, yes, life != multicellular organisms, but maybe it might turn out that eukaryotic and/or multicellular life is the only real "interesting" kind of life from the most broad perspective.
However I vehemently disagree that multicellularity is the "only interesting kind of life". We don't even know yet if life of computational origin exists so as to be able to call it life per se. We don't know lots of things. It's just hubris to act as if we have enough information to make such strong claims.
So multicellular organisms came before high oxygen levels.
You can't say that "but we will find disproving material in the future so this is not fact". If this kind of argument is valid, I can also say that "you will be wrong anyway in the future so you are just wrong all the time". Do not use future to determine today.
If you're going to insult and denigrate entire fields of research, I think you should put your money where your mouth is.
Armed with all of this data, and working on an assumption that current ‘laws’ of physics will continue to apply in the future, scientists can make reasonably confident predictions.
Similar approach, though admittedly with far less mathematical modeling, is also the case in biology. Even textbooks and scientific resources have to assume, at some point, that we start with a framework of axioms.
But most science textbooks also first introduce the idea of models, hypothesis and the notion that a ‘law’, is only as good as the most recent experiment that supports it - and that the scientific method requires us to discard or amend the ‘law’ if new evidence contradicts its predictions. To keep repeating this foundational idea every step of the way seems tedious - it’s reasonable to treat gravity on earth as a fact in the face of overwhelming observational evidence, for instance.
I don’t see how any of this reflects hubris and unwillingness to admit what we don’t know.
For instance, as an (ex-)biologist, I completely agree we do not have a good model for consciousness; or that we simply don’t have a solid functional model of a cell that allows us to model and predict its behaviour at detail and with all its complexity - we are still, in fact, discovering layers of complexity and nuance. But there are some things we do understand well.
Same in physics - the search for a Grand Unifiying Theory continues. ‘Dark matter’, as I understand it, is an acknowledged proxy for many things we don’t yet understand.
So..not sure I agree with your position :)
if we knew all the secrets of the universe we wouldn't be stuck on this rock and dying every 80 years
you have to admit there's some dissonance between claiming to know the fine details of the ancient origins of the universe and struggling to predict if it will rain next week
Of course, there is more than one model, all of them evolve all the time, none of them are perfect (the map is never the territory), and none of them concern themselves with philosophy (a.k.a. unfalsifiable statements about what is “real reality” and the like).
This misrepresentation leads to all sorts of confusion (the quintessential example being light as waves vs. particles), physicalism-by-default (along with illusionism and determinism) as mainstream philosophical worldview among the STEM crowd, and perhaps even distrust to natural sciences among some others.
I blame it on the age-old patriarchal desire to appear a knowledgeable, reputable and indisputable authority to young students, and I’d wager that such people self-select for the job of writing and vetting textbooks.
Any decent science curriculum will cover the inherent mutability of scientific knowledge, the fact that it is just a model that is updated as we add knowledge—these facts and the process of updating the model are the main takeaways of the scientific method. If you weren’t exposed to that sort of stuff, that’s a substantial strike against somewhere’s education system.
Plus, in some cases, especially for younger students, the truth is twisted (even if to the point of being wrong) because the real answer would be a bit beyond their ability to understand. For example, explaining atomic structure as if electrons are just balls spinning around a nucleus or describing light as simple rays.
They're very wrong, but convey enough information to build some other concepts on before the students are able to understand the truth.
This is one study covering a form of life that was largely replaced during the Cambrian explosion, and took place right after massive glaciation , while the environment was very different to today, or even the Cambrian epoch.
The main point of the study is that Oxygen levels may have been lower than thought, which isn't "a problem for science" because "science" isn't even sure if the many fossils from that period were animals (and would require higher oxygen levels).
And for people here who didn't read the article: this isn't about the origins of _cellular_ life, or even multicellular life. Multicellular life had been around for tens of millions of years. And life itself had been around for billions.
This study asks "are we wrong about how much O2 COMPLEX life requires?" And we may be, Because the ediacaran had different life forms than we have now after the Cambrian explosion.
Also it's an odd coincidence, but there is https://en.wikipedia.org/wiki/Ezion-Geber - a city only mentioned in the Bible...
Editing to add: this site has been so much better for my mental health. Still plenty of bad news about the environment and large corporations, etc. but I focus less on it, and much more on topics that rekindle my passion for science and technology.
Not OP, but this chap [1] retraces the early stages of Kant’s thoughts on mathematics [2]. (The commenter concludes it’s all made up because it’s difficult to think about. Fortunately, Kant went further, though he, too, ultimately deus ex machina’d the ending.)
[1] https://news.ycombinator.com/item?id=36863039
[2] https://www.jstor.org/stable/2184079
Math is immaterial so science is fake isn’t a novel perspective [1], it’s literally 17th-century material and a symptom of America’s lack of philosophical education.
[1] https://news.ycombinator.com/item?id=36863039
It's that, too.
You must have a hair-trigger definition of anti-scientific cryptocreationist because I don't see it.
IMO, drawing narrow boundaries around how scientific questions can be discussed is rather anti-scientific, since a search for the truth can't presuppose that truth.
It's great to ask questions about evolution if you're a creationist and you're trying to learn. It gets tiring to recognize that someone is looking to do a gotcha and ignore the explanation of why it's not a gotcha.
If OP meant "that one guy" instead of "many", they could always edit/reply to clarify. For my part, I can only respond to the ideas actually expressed.
https://news.ycombinator.com/item?id=36840674
Or maybe it's intelligence all the way down. A thousand different shapes and sizes of memory, logic, communication, etc. All the way down to cells and beyond.
I like the second theory.
This article is not about the origin of life any more than a book about childbirth is about the origin of life.
Multi-cellular life split into plants and animals ~800myo, during the Avalon Explosion.
Science has long assumed high concentration of oxygen predates animals.
But researchers have now determined that oxygen levels were far lower than thought necessary when evolution of animals started to really take off.
So now we must come up with new theories for origins and evolutionary explosion of animals.
Without humans the moon still would have existed, bound by gravity in an orbit that can be described by what is called math. Discovering and naming a concept does not mean creating it. Antarctica was not created by the person who saw and named it, neither did the first person to try to measure the circumference of a circle decide that it should be 3.14 times the diameter. Whether or not it was measured and named it would still be the same ratio.
https://www.youtube.com/watch?v=KvGdllx9pJU
Hilarious introductions.
Judging from the timeline though going from eukaryotes to procaryotes is weirdly just as tricky if not more so. I mean - eukaryotes showed up after life had been on earth for 1 - 1.5 billion years. Procaryotes showed up almost right after the Earth could conceivably supported life at all.
That's always struck me as really weird. It also makes me think if we ever find alien life we're probably going to be disappointed.