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
The new one with 238 kbp:
> Sukunaarchaeum encodes the barest minimum of proteins for its own replication, and that’s about all. Most strangely, its genome is missing any hints of the genes required to process and build molecules, outside of those needed to reproduce.
Referencing the 159 kbp one:
> However, these and other super-small bacteria have metabolic genes to produce nutrients, such as amino acids and vitamins, for their hosts. Instead, their genome has cast off much of their ability to reproduce on their own.
There's many hypotheses, basically all different variations on "soup of organic compounds forming complex catalytic cycles that eventually result in the soup producing more similar soup, at which point it begins to be subject to differential selection." It's a reasonable idea but where did this happen, and do the conditions still exist? If we went to that place would it still be happening?
There's reason to believe the answer would be no because modern lifeforms would probably find this goo nutritious. So life may have chemically pulled up the ladder from itself once it formed.
This of course assumes no to more fanciful options: panspermia that pushes the origin back to the beginning of the cosmos and gives you more billions of years, creation by a God or some other kind of supernatural or extra-dimensional entity, etc.
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.
> In the redshift range 100 . (1 + z) . 137, the cosmic microwave background (CMB) had a temperature of 273–373 K (0-100◦C), allowing early rocky planets (if any existed) to have liquid water chemistry on their surface and be habitable, irrespective of their distance from a star.
> In the standard ΛCDM cosmology, the first star-forming halos within our Hubble volume started collapsing at these redshifts,allowing the chemistry of life to possibly begin when the Universe was merely 10–17 million years old.
From: The Habitable Epoch of the Early Universe - https://arxiv.org/abs/1312.0613
In comparison, our beloved sun is estimated to have been born 9.2 billion years after the Big Bang, a third of the way into the universe's history so far.
> The Sun is approximately 4.6 billion years old, while the age of the universe, based on current estimates, is about 13.8 billion years.
So our solar system is not that old, relatively speaking. We're among elders, some stars are three times older than the sun.
> In the future, however, life might continue to emerge on planets orbiting dwarf stars, like our nearest neighbor, Proxima Centauri, which will endure hundreds of times longer than the sun’s.
> Ultimately, it would be desirable for humanity to relocate to a habitable planet around a dwarf star like Proxima Centauri b, where it could keep itself warm near a natural nuclear furnace for up to 10 trillion years into the future.
Several caveats apply, chiefly that heavy elements weren't produced for a while in significant quantity, but were produced fairly early on due to large stars exploding relatively quickly, when they were merely tens of millions of years old, if that.
Ejection: https://link.springer.com/chapter/10.1007/3-540-25736-5_3
Reentry: https://journals.plos.org/plosone/article?id=10.1371/journal...
Not to mention the constant trickle of "X survived in space" stories that we get every time someone bothers to collect and culture a sample. The amount of success at every stage with, frankly, very little effort spent tuning the conditions, multiplied by "bacteria are everywhere" makes hitchhiking less crazy than it sounds. Our intuition misleads us because bacteria are so much better at handling acceleration (easy if you're small) and dessiccation (everywhere is a desert if you're small) than anything we are used to thinking about.
You are being severely restricted by your imagination. You seem to have presupposed that random abiogenesis is impossible and reconstructed the facts to support that claim because you can't conceive of the alternative.
Planets are really, really big. Any one chemical reaction is on the scale of molecules. If you let those figures compound for a long time, the number of total reactions gets very, very large. Far larger than you imagine. Many times more.
1. https://www.chemistryworld.com/news/first-direct-chemical-sy...
I don't see the word "random" anywhere in the article. By random maybe you mean it's seemingly indeterministic? Regardless of the nature of the underlying process, at the classical level, the environment acts as a deterministic filter, ie, other chemical processes.
The TLDR of his theory is that life originated in alkaline hydrothermal vents on the ocean floor, where natural energy gradients could have driven primitive metabolic reactions before the development of DNA.
Book goes into a lot of layperson-accessible detail.
Why spend time making this point? Nobody believes that this occurred randomly: it occurred via evolution.
The mutations are a random part of evolution, but the process overall is not random at all - no more so than your immune system (which randomly generates antibodies, then selects against those that target innate epitopes), or stable diffusion (which starts with random noise, then marches up a gradient toward a known target).
It is the selection step that makes similar processes non-random, because a random selection step would just be noise.
Evolution is just a sort of way for low entropy structures to form from randomness. It’s still random all the way down.
The man is just trying to reconcile a belief in god with the scientific reality. He needs to bend the evidence to fit his identity he cannot bend his identity to fit the evidence because that could break his identity. The fact he commented here on this topic is sort of unhinged. It seems like the article presented evidence that is strikingly against his world view and he needed to justify something in order to prevent his identity from rearranging itself according to external reality.
Fundamentally, it's impossible to reconstruct something from the fossil record that's convincing to these folks, because they will always arbitrarily decide "fossil 1 is kind X, and fossil 2 is kind Y, you need to find me fossil 1.5," no matter how close in time and likeness the fossils are.
So what they actually want is "evolve a lizard species into cats" which fundamentally misrepresents both A) how evolution works (it does not concern itself with human categories) and B) the vast timescale over which small changes accrue.
"Kinds" are just human categories we've mapped onto the results of billions of years of evolution after the fact.
The point I was making was that the complexity curve has to meet the floor at some point, and thinking about how this happens and what that looks like is interesting.
I was familiar with RNA world but wasn't aware of how much progress had been made.
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?
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
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.
> ... 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.
This is a decidedly Eukaryote-centric take. Homeostasis in higher mammals is a complex network of genes -> RNA -> proteins -> metabolic pathways
Reproduction is also far more simple in organisms with binary fission cellular division.
A more appropriate scientific term would be obligate commensalism vs. "parasitic". That actually encapsulates their need for metabolic precursors from the host, but allows for tRNA, rRNA, origin of replication, etc...present in the organism's genome.
Wikipedia on the definition of life:
> Since there is no consensus for a definition of life, most current definitions in biology are descriptive. Life is considered a characteristic of something that preserves, furthers or reinforces its existence in the given environment. This implies all or most of the following traits: [list of seven common traits of life]
One of the few places I've seen it come up in science, was ecosystem multi-scale simulation software. Where virus was squarely in the heritable characteristics under selection pressure ("life") bucket, rather than abiotic or biogenic.
Informal "do you think of viruses as alive?" seems to vary by field. I've seen a marine bio labs be overwhelmingly yes. I've been told medical immunology leans no. But it seems more social-media engagement question than research question or synthesis.
They are infectious agents, but many life forms are infectious agents.
If you say "well not by themselves" neither do humans.
There is another life property that this object does not fulfill and is called Teleonomia, that is governed by an ultimate goal.
I suggest
If it can reproduce and mutate heritably, it's alive.
I find the idea that viruses aren't alive ridiculous.
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.
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.
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.
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.
Also, as others have noted, your idea is not necessarily wild. Certainly, at the sub-cellular level, there is tremendous evidence that symbiosis played a part in creating "higher level" organisms (i.e., eukaryotes).
Many genomes are like a junk-yard with fossilized relics of infectious agent nucleic acid (e.g., viruses), etc. Apologies for the junk-yard / fossil mixed metaphor.
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.
They aren’t. Apart from DNA replication, transcription, and translation, their genome lacks elements encoding for even the most simple metabolic pathways.
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).
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
This scishow video gives a good look at the tip of the iceberg.
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.
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"
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.
Bacteria, fungus and plants are not usually seen as conscious but are usually seen as alive.
All conscious things are alive (unless AI is conscious) but not all alive things are conscious.
1. Living things locally decrease entropy but globally increase it.
2. Many other processes do the same. As chermi noted, a liquid solidifying has the same characteristic.
Yes, living things locally decrease entropy and that’s my point.
And maybe I should’ve been more clear for people who cannot grasp new understandings, anything that can decrease its own entropy is living.
I mean, do you think life has nothing to do with the organization matter into a lower entropy state?
> 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.
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-o...
But this has been a topic of conversation since the early 1900s. It’s not like I’m saying anything new.
At least own it. Saying someone lacks imagination and creativity and now reading comprehension is absolutely insulting.
> 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.
I can’t look up anything based on your vague comment. That’s why I asked what you mean.
> For instance:
Thanks. I’ll take a look at that article.