> Wouldn't a couple asteroids be the literal drop in the ocean in comparison?
Actually most water on earth probably came from asteroids, so they are the entire ocean! They would also have brought a lot of frozen methane and ammonia, so most of the chemicals necessary for terrestial life.
When the solar system was forming, the protoplanetary ring of cosmic dust would have consisted of heavy elements (some essential for life, such as phosphorus) closer to the sun and frozen lighter elements further away. The heavy elements would have combined into the early rocky earth, and as the other planets formed and orbits stabilized the icy asteroids from further out would have been flung around and impacted the planets.
I don't think you'd want a single homogeneous "large pool", but rather a large variety of different types of micro-environment, including all those that have been suggested as possible environments for the emergence of life - the chemical and physical environments of hydrothermal vents, volcanic hot springs, shorelines, different types of rocks, clays, etc. You'd want to have environments that included all energy sources present on earth (solar, lightening, geothermal), all forms of mechanical agitation/mixing (hydrothermal, waves), etc, etc.
Yeah, but it seems impossible to experiment on the scale that would have happened in nature where there would have been millions of localized "test tube experiments" ongoing for millions of years.
Of course people can, and do, try to replicate early earth environments and self-assembling proto-cells, but I'm not sure how intellectually satisfying any self-replication success from these "designer experiments" would be, unless perhaps done on such a large scale (simulation vs test tube?) that any conclusions could be made about what likely happened in nature - just how specific do the conditions need to be?
My personal theory is that the conditions for life are plentiful in the universe but it probably took an unbelieavable number of random chemical/mechanical events to form the first proto-lifeform.
The discovery comes after these building blocks of life were detected on another asteroid called Bennu, suggesting they are abundant throughout the solar system.
We've barely started to look, other than on Mars, and notably we are seeing possible signs there. There may even still be primitive life there.
If we do find life of Mars, or say Europa, i.e. in the very first places we look for it, that that would be highly suggestive that it is extremely common (at least in primitive form).
Also it seems that finding a balance where an ecosystem doesn’t kill itself with its own waste is probably harder than we assume. Earth life has totally changed the atmosphere of the planet, I would many it many cases even when life does for it kills itself early on
I guess it depends on how you define life, and whether we'd even recognize it when we see it, assuming we're looking in the right places.
I'd also imagine that any type of chemistry that harvests energy from the environment is liable to find itself as a food source at the bottom of the food chain now that earth is teeming with life.
I think that self-replication, and ability to harvest chemicals and energy from the environment to make more of what you're built of, is the point of complexification of chemistry that is best considered as the most primitive form of life. From there you can go on to things that are capable of encoding structure and more complex chemical factories.
I suppose one signature of these earliest type of "emergent life" chemistries would be localized concentrations of things like these nucleobases that we know are the building blocks of life as we know it, but there may be other types of self-replicating chemistries that emerge too, that don't lead anywhere.
> I think that self-replication, and ability to harvest chemicals and energy from the environment to make more of what you're built of, is the point of complexification of chemistry that is best considered as the most primitive form of life
Once there are forms that harvest and self-replicate, however, its expectable that there will be forms that delegate those features to others, like viruses. Cellular machinery that is required to implement those feature is not free, so parasitic forms would have survival advantage.
He's an interesting person overall - the long interview is well worth watching if you haven't already seen it - but the relevance here are his experiments with the emergence of self-replicating computer programs out of random components.
His starting point is entire "programs" (random sequences of 64 characters, of which only ~7 have any meaning - the program "statements" of the BF language), so perhaps more suggestive of this RNA world stage, but perhaps also of what came before it when there may have been collectively self-replicating soups consisting of discrete components rather then entire structural encodings.
Parts of the RNA world theory are correct, but other parts are completely bogus and completely illogical.
What is correct is that RNA must have existed a very long time before DNA, during which RNA was the only nucleic acid.
Moreover, self-replicating RNA must have existed before ribosomes and proteins (where "protein" means a polypeptide that is synthesized using a RNA template).
It should be obvious that neither ribosomes nor protein-encoding RNA-sequences may exist before the existence of self-replicating RNA, because the living being in which those would exist would immediately die without descendants, together with its content of ribosomes and proteins.
So far so good, but some of the supporters of the RNA World theory claim that before the existence of protein-based enzymes, all chemical reactions inside a living being must have been catalyzed by RNA molecules.
This is an illogical claim, which is false beyond any reasonable doubt. Some RNA-based catalysts may have existed quite early, and some still exist today. However, any RNA-based catalyst could have appeared only at a later time after the establishment of RNA self-replication. The argument is the same as for protein-based catalysts, any living being with a RNA catalyst, but without RNA replication would die and the RNA catalyst would disappear without descendants.
So there is no doubt that the first feature of RNA that has appeared was self-replication, and at that time RNA could not have any other role inside a living being, because any such role would not have been inherited.
In other words, the first self-replicating RNA molecules were a kind of RNA virus, which multiplied inside the existing living beings, consuming energy and substances, without providing benefits. Only later, when eventually RNA templates have become the main method for synthesizing the useful components of a living being, something akin to a symbiosis between RNA and the rest of the living being was achieved, arriving to the structure of life that is known today.
For the first self-replicating RNA molecule to appear, the living beings must have contained abundant ATP and the other nucleotides. So the original role of the nucleobases in living beings was not the storage of information, but the storage of the energy required for synthesizing organic polymers. The self-polimerization of the nucleotides, which forms RNA, was an unwanted side reaction. In other words, before the RNA world, there already was an ATP world, which was the first user of nucleobases.
If RNA could not have been the material for making enzymes before the proteins, such enzymes must have been made from peptides (i.e. polymers of amino-acids), exactly like the enzymes of today, but those peptides must have not been synthesized using ribosomes, like the proteins. Such peptides still exist today and they remain widespread in all living beings, and they are named non-ribosomal peptides. Their mechanisms of synthesis are much less understood than the mechanisms of RNA-based protein synthesis. It is likely that more research into non-ribosomal peptides might provide a better understanding of how a living being without RNA could function.
In order to have a self-replicating living being you do not need a self-replicating molecule able to store arbitrary information, like RNA. It is enough to have a chain of synthesis reactions that closes a positive-feedback cycle, i.e. the products of one reaction are reactants for the next reaction and the products of the last reaction are the reactants for the first. If the chain of reactions produces all the components of a living being, growth and self-replication can be achieved.
The defect of such a living being is that evolution is extremely difficult. any mutation in one of the catalysts used in the chain of reactions is more likely to break the positive feedback and lead to death, instead of producing an improved living being. After the appearance of memory molecules, i.e. RNA and later DNA, which can store the recipe for making an arbitrary polymer molecule, it became possible to explore by mutations a much greater space of solutions, leading to a greatly accelerated evolution of the living beings.
I read a few times your comment and I went from "Nah" to "It makes a lot of sense". I'm adding the "ATP word" to my list of interesting ideas.
Some related stuff:
* https://www.science.org/doi/10.1126/science.adt2760 They made RNA that copies itself, but it use as a starting point activated triplets of bases. i.e, if ATP is AR-PPP, they use a mix of something compounds like AR-P-AR-P-AR-PPP that stil have the triphosphate to store energy and be easy to link, but already have tree linked bases. This is even more difficult that a soup of ATP and friends.
* https://en.wikipedia.org/wiki/PAH_world_hypothesis The idea is that before the RNA word, there was something simpler, like this. Is it possible to use ATP to build more PAH? I also remember about a version of RNA that instead of ribose it used something smaller (glicerol?), but I can't find it.
>However, any RNA-based catalyst could have appeared only at a later time after the establishment of RNA self-replication.
RNA by virtue of its biochemistry is capable of self replication already. Sequence affinity alone is sufficient to drive structure formation. But without a template, structure can also form on its own (example of an open access paper exploring one such mechanism under certain conditions, 1).
RNA is not capable of self replication. RNA by virtue of its biochemistry is only capable to be used as a template for replication, but the copying of the template must be done by a different molecular machinery.
If you put almost any RNA molecule in a jar together with monomers, you can wait until the end of time to see its replication.
Normally, RNA can be replicated only by a special enzyme, a RNA-dependent RNA polymerase. This kind of protein is used by many viruses.
It is hypothesized that a RNA molecule with a very special structure might have been used in the beginning as the catalyst for template-controlled polymerization, instead of a RNA-dependent RNA polymerase, to ensure self-replication. Some experiments have suggested that this is indeed possible.
Only after a self-replicating RNA molecule already existed, or if a RNA molecule existed in combination with a RNA polymerase that was produced by other means than by using a RNA template, other RNA molecules with various other functions could appear, and they would have been replicated by the already existing mechanisms, so they would be inherited by the descendants of a living being.
The link provided by you has nothing to do with RNA replication.
It describes a mechanism for the polymerization of nucleotides, which produces random nucleic acid molecules, not molecules that replicate an existing template.
A chemical reaction of this kind is what must have existed before the appearance of a self-replicating RNA molecule. Among the many random polymers produced before that, there was eventually one capable of self-replication, which started the evolution of genetic information.
This kind of reaction is what I have referred to as "side reactions" that happened during the use of ATP and of the other nucleotides as energy sources for the polycondensation reactions used in living beings to make macromolecules.
> RNA is not capable of self replication. RNA by virtue of its biochemistry is only capable to be used as a template for replication
RNA molecules which can synthesize others have been produced in a lab.[1,2] Your claim is not only totally unsupported, it's been experimentally disproven.
Laboratory RNA production can be done with regular batch chemistry - no enzymes involved, so on a long enough time span heat and mixing would be able to polymerase candidates out of the primordial soup.
RNA self-affinity is well documented, double-stranded RNA viruses exist[2] so stable conformational arrangements of RNA are not only experimentally proven but so viable they exist in todays much more enzymatically hostile world.
The relative difficulty of the structure persisting is a point in favor it is as a replication medium, since if RNA could tightly bind RNA then templating new strands would inactivate it.
You sound awfully confident about this, given we have no direct evidence for most of your claims. I would find your writing more convincing if you didn't make absolute statements.
It's a sample of one, but I think the takeaway is just that if the nucleobases are present on a random asteroid then they probably commonly occur. Of course as you note it takes a lot more than that to form these into nucleic acids.
I would guess there is a more primitive stage in the emergence of life where self-replicating soups (Kaufmann: metabolisms), including things like nucleobases and amino acids, capable of collective replication/expansion exist, before we get anything as sophisticated as nucleic acids and structural encoding.
Most responses here are reacting to the specifics of ATMs and bank tellers, but I think the more interesting point, which seems to be the point of the story, is that paradigm shifts (e.g at-home vs at-the-bank banking) can be more disruptive than automation.
The interesting question of course is what paradigm shifts may be enabled by AI? Certainly all the use case emphasis so far has been on automation, whether that's businesses using agentic workflows to replace manual ones, or agentic coding tools to automate the coding (and to much less degree software engineering) process. So far it's all mechanical horses.
For example, maybe (I don't see it, but maybe) the need for software goes away entirely since it's just an intermediary to getting something done. What if the AI can just do things for you directly, given specific instructions? Rather than giving detailed instructions to an AI to help you code some software, you (or someone/something) instead just bypass that step and give it detailed instructions to do whatever the software would have been used to accomplish.
As another off the top of my head example, what about healthcare? Are doctors and doctors offices the tellers and banks? We need to advance from brittle LLMs to robust AGI first, but at-home diagnosis and prescription could certainly replace many routine doctors office visits.
Domestic appliances were extremely disruptive. (vacuum cleaners, fridges, washing machines, air conditioners, ...) Domestic servants were eliminated. But there was no paradigm shift.
People still live in houses and prepare and store food, and clean their houses and clothes. Minor tasks of domestic servants (making beds, tidying, etc.) were folded in to the job of the homemaker, who was demoted from a supervisory role.
Mainframe computers emptied out accounts departments in large companies, eliminating invoicing clerks, general ledger clerks, stock control clerks, payroll clerks and many more specialised roles. No paradigm shift. Accounting is still accounting.
Typing pools were emptied by the introduction of the Lasrjet printer and the personal computer. Their minor tasks (spell-checking, grammar correction, etc.) were taken over by other people. No paradigm shift, just a task automated.
Telephone operators were eliminated by automatic exchanges (central and customer-premises). No paradigm shift, that came later with digital radio phones ("smartphones"), and didn't cause wholesale job elimination.
The binary distinction between task replacement and paradigm shift is flawed. Reality is much more varied and fluid.
I have a hard time believing that Redbox had much of an impact on Blockbuster, and they certainly weren't changing the video rental paradigm.
Netflix's original DVD-rental by mail business no doubt ate into Blockbuster's business to some degree, and with their huge inventory was more of a head-on competitor than Redbox which could only offer a vending-machine full of options - the most popular ones.
What really killed Blockbuster was streaming video, not just a way of "automating" the DVD rental business - it was the paradigm shift, similar to the mobile banking vs ATM shift that TFA describes.
That sounds logical but the timeline doesn’t match up. Blockbuster filed for bankruptcy in 2010. This came after years of decline.
Netflix streaming launched in 2007 and ended 2010 with only 20 million users. (They currently have over 15x that). I was using it from the start, they had barely any content back then, Hulu was pretty new, and that was the entirety of the streaming universe. Netflix’s first major original content, House of Cards, came out in 2013.
Blockbuster peaked in 2004. Redbox was just getting started.
Blockbuster’s fall loves to get shoved into 100 different narratives, none of which match the facts. It was death by 1,000 papercuts. Netflix. Redbox. Cable system technology improving drastically. Cable TV improving drastically (this happened right around the time Blockbuster peaked, great book on how/why called Difficult Men). TV show quality in general improving drastically. The rise of HBO. Poor management. Etc.
Yes, that sounds about right. I was too glib in saying that it was video streaming was the cause - one of the final nails in the coffin, perhaps.
As I recall Blockbuster was really in it's heyday in the VHS era, and the largest selection was always VHS even when DVD and then Blu-ray came on the scene.
Digital of one form or another - DVDs and streaming - was the future, and Blockbuster never really fully embraced it, instead just becoming increasingly irrelevant as various alternatives emerged.
It was fun while it lasted though - there was something about the experience of going to Blockbuster, or any of the smaller local video rental stores, and choosing something for movie night. I never really saw the appeal of the Netflix approach of having a want list and not really having control over what they mailed you, as well as the delay of mail.
Actually most water on earth probably came from asteroids, so they are the entire ocean! They would also have brought a lot of frozen methane and ammonia, so most of the chemicals necessary for terrestial life.
When the solar system was forming, the protoplanetary ring of cosmic dust would have consisted of heavy elements (some essential for life, such as phosphorus) closer to the sun and frozen lighter elements further away. The heavy elements would have combined into the early rocky earth, and as the other planets formed and orbits stabilized the icy asteroids from further out would have been flung around and impacted the planets.
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