7 ms·
A cell so minimal that it challenges definitions of life
- cnnlives1987 1y agoWe don’t even fundamentally understand physics yet. Certainly there is much to life that we don’t understand.
- jacquesm 1y agoThis is not so much about the understanding of life as it is about the definition of life.
- IAmBroom 1y agoEh, you're quibbling with words. We're getting closer to the quantum (indivisible) definition of life, and that's understanding.
- willis936 1y agoI don't think that they are. The term life, as it's currently defined, is not very useful. The reality is that there is a very colorful spectrum of microscopic biology and that a single bin of "alive" and "not alive" is like trying to paint the mona lisa with a single pixel. This scishow video gives a good look at the tip of the iceberg. https://youtu.be/FXqmzKwBB_w https://youtu.be/FXqmzKwBB_w
- Noaidi 1y agoAs they said in another comment, life is the ability to decrease entropy. That definition would tie in quantum mechanics.
- tshaddox 1y agoI don’t think a precise definition of life is particularly important or of particular interest to most biologists. This thing is life in the sense that it’s definitely in scope of being studied by biologists (same is true for viruses, of course). And the reason it is speculated that it may be crucial to understanding life is mentioned in the article: “This organism might be a fascinating living fossil—an evolutionary waypoint that managed to hang on.”
- russdill 1y agoWe understand enough physics to model all the possible interactions life might have on this planet. Unless this planet is having a really bad day.
- HarHarVeryFunny 1y agoMaybe better to say "We understand enough physics to model all the possible interactions PHYSICS might have on this planet". There are many levels of abstraction between quantum/particle physics and life, or even just cosmology (things like dark matter, etc), that we really know very little about.
- HarHarVeryFunny 1y agoAn interesting counterpoint to how little we know, and/or how useless in practical terms our quantum level understanding of physics is, is chemistry. Chemistry is adjacent to physics, at least classical physics and the standard model, so you might think that we should be able to use our knowledge of physics to determine things like atomic bond "angles" and the protein folding problem, yet even this smallish step up in abstraction from physics puts us in a realm where we know very little. DeepMind's AlphaFold, now able to correctly predict 90% of protein folding in agreement with experimental determination, is mostly based on learning from experimental data, as well as evolutionary consideration of proteins that co-evolved, etc. It makes you wonder how useful the reductionist model really is in terms of understanding higher level dynamics. Maybe different levels of abstraction like physics, chemistry, etc, are really a lot more independent than is commonly thought.
- bloomingeek 1y ago[flagged]
- aydyn 1y ago[flagged]
- bloomingeek 1y agoMe thinks, sir, you think you knowth, but not.
- aydyn 1y ago[flagged]
- bloomingeek 1y agoYou misunderstood my original statement. SCOTUS struck down RvsW, which I think is wrong- both morally and scientifically. You shouldn't name call, leave me alone or I will report you.
- aydyn 1y ago[flagged]
- tomhow 1y ago> Its easily googlable or ChatGPT-able. Dont be intentionally dense. You are just making your "side" look dumb. This is an unacceptable comment on HN. It breaks several guidelines, including those listed below. Please read the guidelines and make an effort to observe them whenever participating here. We've had to ask this of you multiple times previously. Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes. Comments should get more thoughtful and substantive, not less, as a topic gets more divisive. When disagreeing, please reply to the argument instead of calling names. "That is idiotic; 1 + 1 is 2, not 3" can be shortened to "1 + 1 is 2, not 3." Please don't fulminate. Please don't sneer... Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
- flobosg 1y agoSee also: “Microbe with bizarrely tiny genome may be evolving into a virus” – https://www.science.org/content/article/microbe-bizarrely-tiny-genome-may-be-evolving-virus https://www.science.org/content/article/microbe-bizarrely-ti...
- IAmBroom 1y agoWhich, BTW, is about the same researcher and microbial host/parasite pair. More info, so I'm not complaining.
- flobosg 1y agoYeah, I should have mentioned that. Article about the same topic and preprint, but released earlier this year.
- HarHarVeryFunny 1y agoMaybe devolving would be a better term if that's the case
- XorNot 1y agoReminds me of how the discovery of giant viruses - like truly huge viral particles - was immediately also followed by discovering "virophages" which parasitized them. Which of course makes sense to some degree: if an adaptive strategy is successful enough, then parasitizing something which successfully implements it is going to be resource favorable (and likely, presumably by being a member of that species and just shedding components you don't need if you take them).
- IAmBroom 1y agoIndeed. Well deduced. Inevitability of Genetic Parasites Open Access Jaime Iranzo, Pere Puigbò, Alexander E. Lobkovsky, Yuri I. Wolf, Eugene V. Koonin https://academic.oup.com/gbe/article/8/9/2856/2236450 https://academic.oup.com/gbe/article/8/9/2856/2236450
- flobosg 1y agoUnsurprisingly maybe, DPANN archaea can also host viruses: https://www.nature.com/articles/s41564-025-02149-7 https://www.nature.com/articles/s41564-025-02149-7 (Paywalled, but there’s a preprint at https://www.biorxiv.org/content/10.1101/2025.02.15.638363v1 https://www.biorxiv.org/content/10.1101/2025.02.15.638363v1)
- deleted 1y ago[deleted]
- djoldman 1y agoFrom the paper: https://www.biorxiv.org/content/10.1101/2025.05.02.651781v1 https://www.biorxiv.org/content/10.1101/2025.05.02.651781v1 > ... we report the discovery of Candidatus Sukunaarchaeum mirabile, a novel archaeon with an unprecedentedly small genome of only 238 kbp —less than half the size of the smallest previously known archaeal genome— from a dinoflagellate-associated microbial community.
- russdill 1y agoFor comparison, the smallest bacteria genome, nasuia deltocephalinicola, is 139 kbp.
- smollOrg 1y ago> According to the shocked researchers What is this, some content creator run Biohacker Lab in some basement on Microflix premises? Ominous voice: the tiny cell withdrew into the cracks of existence and saved it's entire code to be in the lines between, the Singular Point which was neither a fraction of space, nor a unit of time, hidden in the void of Chututululu's (33rd degree cousin of Cthulhu) dreams, written in the unspeakable language of the subtext of the book of neither life nor death, that nobody would decipher until the time was right AND GODZILLA GETS TO WALK THE EARTH AGAIN.
- IAmBroom 1y agoThey were shocked. It is shocking.
- moffkalast 1y agoWell tell them to quit playing with the stun gun.
- zkmon 1y agoThe ultimate form of outsourcing.
- b3lvedere 1y agoWhich makes C. Regius a very tiny CEO? :)
- falcor84 1y agoOnly if it has a mechanism to send signals into the host and cell. For the CEO metaphor to hold, I'll accept that these signals can be entirely ignored, but they need to be transmitted.
- zkmon 1y agoThere must be some interaction with the host involved. Otherwise there is no point in being hosted or stripping off own features.
- falcor84 1y agoWhat do you mean? The interaction described in the article is just of the small cell stealing nutrients from the host's pouch. That seems like enough of a "point" for the parasitic cell, while giving it zero incentive to advertise its presence with signals.
- pretzellogician 1y agoVery impressive! To be clear, this is not the smallest known bacterial genome; only the smallest known archaeal bacterial genome, at 238k base pairs. In the article they mention C. ruddii, with a smaller 159k base pair genome. But according to wikipedia, it seems N. deltocephalinicola, at 112k base pairs, may be the smallest known bacterial genome. https://en.wikipedia.org/wiki/Nasuia_deltocephalinicola https://en.wikipedia.org/wiki/Nasuia_deltocephalinicola
- flobosg 1y agoA nitpick: Although similar in some aspects, archaea are not bacteria; they are classified under their own phylogenetic domain.
- api 1y ago[flagged]
- smallmancontrov 1y ago1. Autocatalytic RNA reaction networks -- "soup producing more soup" -- are easily replicated in the lab, subject to Darwinean processes, and are at the center of ongoing study. "0 to Darwin" is now easy, "Darwin to Life" is the new focus, and God of the Gaps must retreat once again. 2. Spores hitchhiking on impact ejecta sounds exotic until you realize that anywhere life is present at all spores will be everywhere and extremely sturdy. That desktop wallpaper you have of planets crashing together and kicking off an epic debris cloud? Everything not molten is full of spores. 3. Religious explanations are not in the same universe of seriousness as 1 and 2. Opening with a religious talking point and closing with a false equivalence is mega sus.
- bavell 1y agoWould love to see some sources for #1. #2 sounds plausible but speculative?
- smallmancontrov 1y ago
- codedokode 1y ago> the bacterium Carsonella ruddii, which lives as a symbiont within the guts of sap-feeding insects, has an even smaller genome than Sukunaarchaeum, at around 159,000 base pairs 159 000 base pairs is ~320 Kbit, or 40 KBytes. I wonder, if that is the minimum size of a cell firmware. Also, if the cell is that simple, can we study it exhaustively and completely? Like, decipher every base pair in DNA, and determine what it is responsible for. And make an interactive website for that.
- ErroneousBosh 1y agoThis is the biological equivalent of sectorlisp.
- agumonkey 1y agoMakes me wonder, do geneticist count epigenetic methylation as information to add to the genetic information set ?
- codedokode 1y agoIsn't methylation more like temporary variables?
- agumonkey 1y agoKinda but they matter for the live being. Also there's hints that it impacts inherited traits too
- circuit10 1y agoThat’s about the same size as the original Super Mario Bros
- empiricus 1y agoI think the genome might be mostly just the "config file". So the cell already contains most of the information and mechanisms needed for the organism. The genome is config flags and some more detailed settings that turn things on and off in the cell, at specific times in the life of the organism. From this point of view, the discussion about how many pairs/bytes of information are in the genome is misleading. Similar analogy: I can write a hello world program, which displays hello world on the screen. But the screen is 4k, the windows background is also visible, so the hardware and OS are 6-8 orders of magnitude more complex than the puny program, and the output is then much more complex than the puny program.
- stevenjgarner 1y agoIsn't replication the single most important act of metabolism for an organism? I am trying to reconcile their ""lost genes include those central to cell metabolism, meaning it can neither process nutrients nor grow on its own" with their "The organism’s “replicative core” — the genetic components needed to reproduce itself — remains, making up more than half of its genome". Replication (making DNA, RNA, and proteins, and ultimately dividing) is a highly energy-intensive and material-intensive process. What appears to be lost by Sukunaarchaeum are the genes to build basic building blocks (amino acids, vitamins, nucleotides) from scratch. It cannot find a sugar molecule and break it down for energy (it can "neither process nutrients nor grow on its own"). Yet it can take pre-made energy and building blocks and assemble them into a new organism. What is the exact line between the host's metabolic contribution and the archaeon's replicative assembly? How "finished" are the raw materials that the host provides, and how does the archaeon's extremely reduced genome still manage the subsequent steps of self-replication?
- sigmoid10 1y agoYou could argue the same way for a lot of parasite species, many of which are ridiculously more complex. Is a complex multicellular organism (an animal even) not alive because it needs to get some component needed for its reproduction from another species? If you get hung on such specific components, where do you draw the line?
- pron 1y agoAs I understand it, it's not so much that they got "hung up" on some specific capabilities for theoretical reasons, but that it's rare to find cells without these capabilities. In other words, it's nature that seemed so "hung up" on these things.
- sysguest 1y agowell people want simple models and explanations -- just like physicists want to model cows as "spherical boing boing cows"
- 1y ago
- Y_Y 1y ago400K should be enough for any body
- kylehotchkiss 1y agoMaybe this is a case of an inception of overlapping genes?
- freakynit 1y agoI’ve been thinking about a wild theory regarding the incredible biological complexity we see in mammals today. What if our bodies (apart from the brain) are actually the result of an ancient aggregation of once-separate "organisms" that evolved to live symbiotically? Over millions of years, their DNA might have fused and co-evolved into a single, unified genome. What began as cooperation between distinct life forms could have gradually become inseparable, giving rise to the intricate multicellular systems we now take for granted.
- deleted 1y ago[deleted]
- luxcem 1y agoIt's called Symbiogenesis [0] and it's not at all a wild theory. But it's limited to cell components, not multiples organs fusing to create something as complex as a mammal. [0] https://en.wikipedia.org/wiki/Symbiogenesis https://en.wikipedia.org/wiki/Symbiogenesis
- Noaidi 1y agoI believe that we’re living in that situation now. I don’t think life can be divided into smaller organisms. That there is just one complex life that we failed to see based on our past prejudice.
- esafak 1y agohttps://en.wikipedia.org/wiki/Intragenomic_conflict https://en.wikipedia.org/wiki/Intragenomic_conflict
- caymanjim 1y agoThis isn't a wild theory or a novel one. It's well-established that endogenous retroviruses alter DNA and are inherited. In addition to the primary genome being modified this way, all mitochondria are symbiotic organisms inside plant and animal cells, with their own DNA, and are vital to life. Same thing for chloroplasts in plants. And then there are gut bacteria, which are vital to life, symbiotic, and directly influence evolution and the genome.
- 1y ago
- Noaidi 1y agoLife is the process of decreasing entropy. If they stick with that definition, they’d be fine. And they’d find out that life is even more abundant than they can imagine.
- chermi 1y agoWhat? A liquid solidifying is life?
- Noaidi 1y agoWater does not decrease its own entropy. If you can’t understand the distinction I’m making then you do not have the imagination and creativity to create new understanding.
- dpark 1y agoA glass of water in a cold environment radiates away heat until it freezes, decreasing its local entropy and increasing global entropy. > If you can’t understand the distinction I’m making then you do not have the imagination and creativity to create new understanding. Perhaps you could explain your distinction instead of insulting people. It’s possible you have some interesting and insightful distinction but as of now you’ve not explained it nor given any examples of this “more abundant” life.
- Noaidi 1y agoI’m not insulting you. I’m pointing out a reality. You’re reading comprehension is failing you right now. Water does not freeze itself. That is the distinction. But myself, as a living being, can turn water into ice. And I can create an organize materials inside of my own body. I pointed out something interesting. The least thing you could do is actually look up to see if there’s any validity or research on what I’m talking about. By more abundant life, I’m talking about how the definition of life we have is limited, but it’s ever expanding based on the papers of the original post. I’m talking about a greater expansion of our understanding of life that’s discussed in papers that deal with entropy and life. For instance: https://www.quantamagazine.org/a-new-thermodynamics-theory-of-the-origin-of-life-20140122/ https://www.quantamagazine.org/a-new-thermodynamics-theory-o... But this has been a topic of conversation since the early 1900s. It’s not like I’m saying anything new.
- tete 1y agoTalking about tiny cells and staring at a tube with liquid. Made me chuckle.
- subroutine 1y agoImpressive. However, still a-ways to go before its as degenerate as viruses like SARS-CoV-2 (which have an order of magnitude fewer base-pairs)
- deleted 1y ago[deleted]
- andrewflnr 1y agoThis is cool but doesn't say much about the definition of life IMO. They're obligate parasites. This isn't a new category. They're still eating stuff from their host (probably, given the caveat later in the article), and still using it to replicate, it's just a more limited diet.
- flobosg 1y ago> They're still eating stuff from their host They aren’t. Apart from DNA replication, transcription, and translation, their genome lacks elements encoding for even the most simple metabolic pathways.
- andrewflnr 1y agoThen where are they getting the materials to replicate? Where are they getting the energy? Magic? No, they're pulling pre-metabolized materials and energy from the host.
- flobosg 1y agoWhich is exactly what I said.
- catlikesshrimp 1y agoVirus are simpler and have challenged the definition of life for a long time already. This article excludes virus from life because they lack ribosomes. Last time I checked, they are considered "not alive" when outside of a host, and "alive" when inside a host. About size: "Genome size varies greatly between species. The smallest—the ssDNA circoviruses, family Circoviridae—code for only two proteins and have a genome size of only two kilobases;[61] the largest—the pandoraviruses—have genome sizes of around two megabases which code for about 2500 proteins" https://en.wikipedia.org/wiki/Virus https://en.wikipedia.org/wiki/Virus
- threethirtytwo 1y agoThe definition of life is also uninteresting. At its core it is just a vocabulary and classification issue. We humans invented the word life and we humans chose to make the word vague, confusing and differently defined among different people. An arbitrary vocabulary and definitional choice for a word “life” is not in actuality interesting to think about. Yet people get hung up about it as if it’s a philosophical problem. It is not a philosophy problem. The word is loaded and you’re simply spending an inordinate amount of time trying to define some made up boundary of what fits this category you made up. It is a communication problem disguised as deeper.
- pfdietz 1y agoIt's like the word "planet", ultimately a tired game of definitions.
- saikia81 1y agoIt is a question in philosophy. It is the difference between being considered a conscious being, and not. Since for now our definitions of a conscious being is tied to being alive (when is a human alive and not death?). So obviously it has implications on ontological questions. It fundamentally limits our understanding of what exists and just as important, why we exist.
- dagss 1y ago
- tbrownaw 1y agoCan we also study very small collections of sand to challenge the definition of what counts as a heap?
- kylehotchkiss 1y agoThis sounds more like a SuperVirus than a cell to me ¯\_(ツ)_/¯
- ____tom____ 1y agoThe standard definition of life is too restrictive. I suggest If it can reproduce and mutate heritably, it's alive. Or, in other words, things that can evolve. I find the idea that viruses aren't alive ridiculous.
- 3cats-in-a-coat 1y agoAtoms and sub-atomic particles fit this definition. Machines fit this definition. Fire fits this definition. Truth is "life" is not a distinct category. We just think of life as complex life. A complex system that mines energy gradients to preserve and replicate its forms. But there's no hard boundary. It's just in our head.
- halestock 1y agoHow do any of those things fit that definition?
- nrhrjrjrjtntbt 1y agoCode can fit the definition. Genetic algorithms.
- ____tom____ 1y agoYep. People always come up with people-centric definitions. They need to be updated based on what are the fundamental characteristic of something that is alive. The current, more standard definition, seems to be based on metabolism. I disagree and argue for reproduction and evolution.
- ____tom____ 1y agoNo, none of those can mutate, that's the point of "and mutate heritably" Crystals can "reproduce", but it's always the same (there can be errors, but they don't inherit), so they don't count. And atoms don't reproduce, so I'm missing your point there.
- rbartelme 1y agoFor all the folks saying, "Isn't this just a virus?" The actual paper states that the genome encodes transfer RNA's and ribosomal RNA's. I think that's a really important biological distinction missing from the popular press junket. The primary source material is well written and elucidates a lot more than the Quanta article. https://www.biorxiv.org/content/10.1101/2025.05.02.651781v1 https://www.biorxiv.org/content/10.1101/2025.05.02.651781v1
- tsoukase 1y agoLife's two most fundamental properties are homeostasis and reproduction. The loss of these two combined with its parasitic nature makes this cell a form on non-life.
- anothernewdude 1y agoLots of types of life give up on homeostasis along particular dimensions because the environment is doing it well enough. Viruses do reproduce. If you say "well not by themselves" neither do humans.
- tsoukase 1y agoNo life exists "by themselves". Self-replication means using only its own DNA and not mangling with other's. Virii are not only parasites but dead matter (a ribonucl molecule surrounded by proteins that happens to stick to other cells, like dirt on the skin). Gut microbioma is parasite. There is another life property that this object does not fulfill and is called Teleonomia, that is governed by an ultimate goal.
- anothernewdude 1y ago> that is governed by an ultimate goal. I have bad news for you. Again, it's humans.
- agumonkey 1y agohow do biologist consider virus like replication then ? which is a two-part system, the virus + the host (and even, a dense population of hosts)
- dredmorbius 1y agoViruses are considered infectious agents rather than life forms per se. <https://en.wikipedia.org/wiki/Introduction_to_viruses https://en.wikipedia.org/wiki/Introduction_to_viruses>
- citruscomputing 1y agoHm. Not the biggest fan of the "parasite" framing given how little we know. I feel the default should be something more like lichens.
- Sniffnoy 1y agoSo... where does it get its ATP? The article says it's lacking pretty much all metabolism -- does that include cellular respiration and/or fermentation? Does it just get its ATP all from its host, or does it make some itself and get some from its host, or what?