Life on Earth didn’t arise as described in textbooks
science.ku.dk
science.ku.dk
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.)
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.
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.
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.
So multicellular organisms came before high oxygen levels.
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.
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.
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.
https://www.youtube.com/watch?v=KvGdllx9pJU
Hilarious introductions.
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.
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.
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?"
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.
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.