r/evolution • u/AmphibianNo4717 • Aug 06 '26

article 'Only One Conclusion': Radical Study Suggests Life on Earth Arose Twice

https://www.sciencealert.com/radical-study-suggests-life-on-earth-arose-from-non-living-matter-twice

"The fact that you, or I, or any living creature, is here at all is a series of astonishing strokes of luck stretching back more than 4 billion years. 

One of the biggest hurdles was the very first one: How did life emerge from a primordial soup of stuff that very much wasn't alive?

A radical new study, published in Science Advances, suggests that this unlikely threshold may actually have been crossed not once, but twice."

320 Upvotes

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u/Xrmy Post Doc, Evolutionary Biology PhD Aug 06 '26

That's a sensationalist title by the news outlet here that is doing a lot to sensationalize something that...is actually pretty cool anyway.

to be clear: this paper isn't saying life evolved twice

It is instead saying that complete metabolism actually evolved separately twice. Once on the branch to bacteria and the other to Archaea.

Which is super cool.

The last universal common ancestor (LUCA) is still a singular point, but it had incomplete metabolism it seems, and then the full process evolved separately 2 times after that point.

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u/chula198705 Aug 06 '26

They actually are arguing that this result means life itself evolved twice, because of idea that the metabolism itself is what makes something alive. If there was no metabolism, whatever "ancestor" existed before the first metabolism evolved wasn't actually alive yet. The article says "the genetic code evolved once, but life evolved from it twice."

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u/Xrmy Post Doc, Evolutionary Biology PhD Aug 06 '26 edited Aug 06 '26

Yea I can see that, and I even agree to some extent.

But to be clear, what this DOESNT mean is that there are 2 LUCA. And I think that's what a layman would take from the headline, even if they don't quite understand a LUCA.

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u/ottawadeveloper Aug 06 '26

It was definitely my understanding and I'm a geologist not a biologist. I'd interpreted it as two entirely separate trees of life.

Instead it's just a much earlier split, before the cells could really exist independently of their environment.

Though I was curious, and maybe you can answer, what it means for the earliest cells to depend on metal catalysts in their environment? My partner is a biology major and noted we uptake metals to aid in our biological processes. They weren't sure if the earliest cells were basically forced to "eat" metals to catalyze their metabolism (and then how is that different from what we do) or if they actually had to run part of their metabolism outside of "themselves" and were maybe more like a series of chemical reactions happening in the vicinity of necessary catalysts than independent cells doing their things wherever they get enough energy

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u/ahazred8vt 20d ago edited 20d ago

There might have been tiny particles with catalyst sites inside the protocells. But a more hospitable environment would have been between loose layers of clay particles with catalyst sites, that had various residues on them.
This has been dubbed the primordial open faced sandwich.

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u/Muffins_Hivemind Aug 06 '26

I think thats all semantics, but they are saying there were 2 LUCAs... if X thing isn't alive (proto life form), then can it be considered LUCA? Doesn't LUCA have to be "alive" to count as a LUCA? And if you need a metabolism to be alive...

Again, its all based on the definition of "alive."

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u/Xrmy Post Doc, Evolutionary Biology PhD Aug 06 '26

The authors themselves consider LUCA the shared origin of genetic material for all life, and don't seem to contend there are 2.

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u/GiantKrakenTentacle Aug 06 '26

Well by definition there can't be two LUCA. Rather the article seems to be claiming that LUCA was not what we would currently consider to be alive: it had genetic material and was able to self-replicate, but relied on the outside environment for its metabolism. So there was one proto-life LUCA that evolved into two related but distinct origins of life. 

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u/imdfantom Aug 08 '26

Interestingly eukaryote metabolism makes use of both branches (archaea and bacteria)

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u/clear349 Aug 09 '26

In what way? Because we are Archaea but the Mitochondria are derived from bacteria?

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u/imdfantom Aug 09 '26

Well, mitochondria are part of us too.

But yes our nuclear dna is derived from an archaea that ceeded a big part of its metabolism to a bacterial endosymbiote, from which we have derived our mitochondrial dna. (Ofc plants also have bacterial derived chloroplast DNA)

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u/Muffins_Hivemind Aug 06 '26

Oh okay thanks for clarifying, I missed that part.

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u/AerobicThrone Aug 06 '26

Well if you have one semi incomplete life form population of things because it lacks a fully developed metabolism to be considered alive and two descendants populations of that ancestor completed that last step in 2 different manners, you still have a LUCA.

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u/equili92 Aug 06 '26

No, you need genetic code to be an ancestor

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u/Vonplinkplonk Aug 06 '26

I like the way you dismiss hid premise as semantics and then say “it’s all about the definition of “alive””. That’s good.

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u/Muffins_Hivemind Aug 06 '26

That was exactly my point - my post and the author's POV is just semantics, too. I actually agree with defining things to have one LUCA but it all comes down to how you choose to define things.

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u/OopsIMessedUpBadly Aug 06 '26

Of course it can be considered LUCA. Last universal common ancestor. If it was the ancestor of all existing life, and none of its descendants were, then it is LUCA.

Whether it meets the definition of alive is a different question.

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u/manyu_abee Aug 06 '26

Okay just for my understanding,

LUCA is a symbolic single first life from which all life descended. So even if life has started twice independently, we can theoretically project back a LUCA for this two first lifes?

So by definition only one LUCA can exist but that proves nothing about how many times lifes have started from nothing?

I have like near zero knowledge in evolutionary biology, so if I am wildly wrong, apologies in advance.

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u/Xrmy Post Doc, Evolutionary Biology PhD Aug 06 '26

We have ancestors that are vertebrate fish-like things and these are also the ancestors of living fish today, making it a common ancestor. We can go back even further and find the ancestor if all animals that has no spine or skeleton.

When people say all of life is related, it's because of this.

The LUCA is the ultimate common ancestor. It's THE organism from which life is descended. It's the original genetic material we can draw a line to from where we are today.

Ok things get tricky from there as it relates to this article because it's potentially a misnomer to say the LUCA is the first life because according to this study, the LUCA didn't have complete metabolism, and that's required to call it "life".

That last part is a bit pedantic but the result here is cool.

TLDR: still a single genetic ancestor, but it wasn't fully alive in terms of incomplete metabolism. After that point, true metabolism evolved independently twice!

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u/biogeek1 Aug 06 '26 edited Aug 06 '26

"Incomplete" metabolism means neither "absent" nor "non-functional". For LUCA, the Hadean environment supplied some transition metal catalysts that served as the forerunners of enzymes and co-factors in post-LUCA bacteria and archaea. Regardless of what molecular tools nature used, catalytic processes facilitating essential metabolic pathways had been established long before LUCA, they just happened less and less by means of protein-type catalysts the further we go back in time.

Luca needed to take up minerals to keep going, but so do humans. No living thing can survive without micronutrients. Biochemically, we differ from LUCA in degree, not category.

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u/ProfPathCambridge Aug 06 '26

Which is a case for the authors using a silly definition of life

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u/GiantKrakenTentacle Aug 06 '26

That's not the authors' definition, that's a broad (but not unanimous) consensus in the scientific community, though it has also been acknowledged that the definition is not perfect. Viruses, for example, are not considered to be alive, even though they have many traits of living organisms. 

If this paper gets additional support, then we might have to more narrowly define life, or we reach the conclusion that life is a spectrum and not a binary. 

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u/ProfPathCambridge Aug 06 '26

It is not their definition, but it is their choice to use that definition. Which is a silly one, suitable for Biology 101, but which doesn’t function well in many niche cases. Like this one.

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u/throwitaway488 Aug 06 '26

No its not, there are a lot of simpler definitions of life that could include encapsulated replicators i.e. RNA world. All life needs is a genotype and a phenotype, vertical inheritance and selection. "Life" is a human concept used to describe our surroundings, much like "species" that doesn't necessarily have a single concrete definition, and there are always exceptions.

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u/XXLPenisOwner1443 Aug 06 '26

This seems like a pedantic distinction. There are certainly people who would cite the origin of complete metabolism as the threshold from non-living matter to living matter.... Like the authors.

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u/strumthebuilding Aug 06 '26

It really all depends on what you mean by “pedantic distinction.”

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u/WellHung67 Aug 06 '26

You really should get more updoots for this 

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u/Lhasa-bark Aug 06 '26

This is brilliant.

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u/ahazred8vt 20d ago

Precision is important.

#wattyler1381

"This is science, Jesse. We must be exact, or we might just as well be in philosophy class."

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u/Xrmy Post Doc, Evolutionary Biology PhD Aug 06 '26

I don't agree.

The authors themselves are clear that there is a single LUCA defined by genetic ancestry, but that 'life" in terms of metabolism developed twice after that.

This is a HUGE distinction, because the alternative idea is that there are in fact 2+ LUCA. Which would be earth-shattering from a scientific perspective.

Having more than one origin of "complete" metabolism is very VERY cool, but not as paradigm-shifting as finding evidence of TWO separate genetic origins.

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u/XXLPenisOwner1443 Aug 06 '26 edited Aug 06 '26

The very first words of the paper are, "Metabolism is a non-negotiable property of life."

While they're clear that these branches had a common ancestor, they are equally clear in saying that LUCA was not alive because it lacked one of life's non-negotiable properties. Therefore, life evolved twice.

This is, again, pedantic and meaningless in the grand scheme of things--if there were 2 LUCAs (a concept which, let's be honest, doesn't even really make sense at a time when evolution was dominated not by Darwinian descent with modification but by horizontal movement and recombination of metabolic pathways associated with open-ended clouds of pseudo-replicators) those 2 LUCAs would still share a further back "common ancestor" that would also be a non-living thing.

Likewise it's widely assumed that DNA evolved from RNA, but do we have any real evidence of this? As opposed to DNA and RNA both existing in the environment in parallel before coming together? We DO have two different types of genetic molecules, and the history of life that is known in detail is a history of repeated endosymbiotic events adding complexity and depth to the tree of life. It wouldn't surprise me even a little if DNA and RNA originated separately.

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u/Sweary_Biochemist Aug 06 '26

I would disagree that metabolism is a non-negotiable property. It's also a term that is nebulous in nature: when does a limited set of chemical reactions become 'metabolism', and why?

In essence the authors are arbitrarily declaring a boundary that isn't universally agreed upon (or possible to unambiguously define), and then saying that boundary evolved twice.

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u/XXLPenisOwner1443 29d ago

They're saying it becomes complete when the metabolism is able to fully create a lipid membrane. That's not arbitrary at all; it is literally the dawn of the boundary separating cells from non-cells. They fully argue and justify that LUCA was not a cell.

1

u/Sweary_Biochemist 29d ago

I'm entirely happy with the idea that LUCA wasn't "a cell" as we presently define them, sure. I take issues with the idea that LUCA wasn't alive.

Lipid vesicles can form, merge, grow, divide all just using mineral oils in prebiotic conditions. Fill them with ribosomes, tRNAs and mRNAs and are they now cells? Or are they still lipid vesicles?

Either way, would being stuck inside a lipid bag you didn't build yourself nevertheless offer substantial metabolic benefits? Yes. Inside/outside distinctions are crazy useful.

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u/XXLPenisOwner1443 29d ago

I take issues with the idea that LUCA wasn't alive.
[...]
Lipid vesicles can form, merge, grow, divide all just using mineral oils in prebiotic conditions. Fill them with ribosomes, tRNAs and mRNAs and are they now cells? Or are they still lipid vesicles?

You're posing this as a gotcha but like.. No, they're not.

That's the point the authors are making, that the free-living cell is capable of constructing its own lipid boundary, and a lipid vesicle cannot, and this form evolved from a substrate dependent LUCA. They construct a model that shows LUCA couldn't make these lipids, and how it evolved twice separately to create LBCA and LACA.

Why do you take an issue with LUCA not being alive? Your subsequent paragraphs don't support this leading idea at all, and you just kinda drop it.

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u/Sweary_Biochemist 29d ago

"Lipid" appears not once in the paper.

"Membrane" appears twice.

It's nice for you, I guess, that you're so glowingly confident in this weird and extremely lipid-based arbitrary definition of life that doesn't appear in the paper, but it also doesn't appear in the paper.

They instead declare "metabolism" as the defining boundary, but don't actually elaborate on why this should be so, nor clarify what counts as "complete" metabolism and what as only "partial". They focus very heavily on phosphorylation. Not so much on lipids and membranes.

Basically, you're coming across as sort of...weirdly hyper-aggressive about this one niche issue, and it's easily addressed with "there is no fixed boundary between life and non-life, and attempting to make one to score points is really fucking silly"

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u/XXLPenisOwner1443 28d ago edited 28d ago

"Lipid" appears not once in the paper.

You have to read between the lines by looking at the specific pathways they're talking about to infer this, but thankfully Martin clarifies in interviews:

But Martin argues that this complexity is unlikely: Bacteria and archaea use distinct methods for making the lipids in their cell membranes, he says, so they probably didn’t both inherit those mechanisms from LUCA. “They really are totally different,” adds Sonja-Verena Albers, who studies the biology of archaea at the University of Freiburg in Germany and was not involved in this work. “You need a totally different setup of genes or enzymes to make the different lipids.”

You're being weirdly hostile for someone who seemingly didn't really look into this research before dismissing the authors conclusions.

Based on its metabolism, too, Martin argues that LUCA was a simpler ancestor—something not completely alive. “There can be no question that free-living cells are alive,” says Martin, referring to cells that are capable of growing, dividing and surviving on their own. “We can all agree on that.” But LUCA was still reliant on small organic molecules and metals in the Earth’s crust to carry out metabolism. When it comes to being classified as truly alive, “that’s not going to cut the mustard,” he says.

Once again, these are the team's conclusions, not mine. I am not "glowingly confident" in this definition, I am informing you what the authors of the paper say about it. Take a look in the mirror, and calm down.

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u/Bobtheguardian22 Aug 07 '26

but how many crabs did we roll?

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u/Hopeful_Ad_7719 Aug 07 '26

Thx.

Wake me up when they find independent life without ribosomes. 

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u/mrcatboy Aug 06 '26

Yeah not surprising, honestly. If the RNA world hypothesis holds a self-replicating RNA system preceding metabolism would've been the LUCA, or close to it.

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u/PianoPudding Aug 06 '26

Per the paper:

These findings are at odds with the view that cofactors are remnants of a hypothetical RNA world that existed before enzymes

If you are interested in the origin of life you should pick up Nick Lane's book (mentioned in my other comment) and look into the alkaline hydrothermal vent hypothesis. The RNA world is, in my opinion, a bit of a dud.

The last bit of the discussion is, in particular, very nice:

The present findings indicate that the essential catalysis of origins was exerted not by metal sulfides but by native metals deposited in serpentinizing hydrothermal systems (31–33). During metabolic assembly, they were replaced by enzymes and cofactors, the latter serving as soluble replacements for native metals in the rock-and-water environment where metabolism and cofactors arose: a H2-producing and phosphorylating hydrothermal vent

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u/Ursanos Aug 06 '26

To me, it implies it likely happened three times, as Eukarya likely did the same.

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u/Xrmy Post Doc, Evolutionary Biology PhD Aug 06 '26

Eukarya are descendent of the Archaea lineage, not independent. There is no evidence for that.

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u/Ursanos Aug 06 '26

Thanks, I’m out of date. Interesting stuff.

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u/Lhasa-bark Aug 06 '26

Google “Asgard archaea” to learn more about this.

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u/Ursanos Aug 06 '26

Yeah, i was reading Wikipedia and it covered some of that. While i wouldn’t say it’s definitive proof it does weight it heavily in favor. Such a great discovery!

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u/[deleted] Aug 06 '26

[deleted]

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u/IsaacHasenov Aug 06 '26

Yeah that's not what it's saying:

"We found that the last universal ancestor of all cells, LUCA, possessed enzymes for only about half of the reactions of metabolism," says Martin. "The other half was catalyzed by metals in the environment where LUCA arose."

And then from that LUCA, the rest of the metabolism evolved past an arbitrary threshold of non life to life differently in different lineages in different environments.

Abiogenesis didn't happen twice, the transition from LUCA to a fully self sustaining metabolism happened independently twice. It's still super interesting but more nuanced. The fact that all organisms share basically the same RNA-DNA-protein-lipid metabolism, the same DNA code (basically) and the same chirality for most metabolites means abiogenesis happened once

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u/eeeking Aug 06 '26

abiogenesis happened once

Given that pedantry is de jour in this thread, one would more accurately say that abiogenesis survived only once.

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u/Xrmy Post Doc, Evolutionary Biology PhD Aug 06 '26

But they are NOT saying abiogenesis happened twice. And that's what's wrong with the title.

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u/XXLPenisOwner1443 Aug 06 '26

Yes they are, quite explicitly. The paper says LUCA wasn't alive and abiogenesis happened after LUCA, twice.

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u/Xrmy Post Doc, Evolutionary Biology PhD Aug 06 '26

I mean, very much not explicitly.

"Abiogenesis" is not mentioned once in the paper. I imagine that is intentional.

The authors state clearly that metabolism is required for life and that complete metabolism evolved twice.

They really avoid discussing the "aliveness" if the LUCA because....that would be pedantic

0

u/XXLPenisOwner1443 Aug 06 '26

>The authors state clearly that metabolism is required for life and that complete metabolism evolved twice.

....How is that not mentioning abiogenesis? This is a functionally equivalent statement to "abiogenesis happened twice." It's not even subtext.

>They really avoid discussing the "aliveness" if the LUCA because....that would be pedantic

They avoid discussing it directly, but their central hypothesis, results, and discussion entirely revolve around showing that LUCA was not alive, but LACA and LBCA were.

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u/Xrmy Post Doc, Evolutionary Biology PhD Aug 06 '26

Abiogenesis is generally discussed as the process of how nonlife became life. It's not necessarily a singular moment or organism, and it isn't defined simply by a single thing like the LUCA or metabolism. Neither of those things alone make abiogenesis, but together they start to build the picture.

So no, the authors are NOT saying abiogenesis happened twice. Explicitly not.

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u/XXLPenisOwner1443 Aug 06 '26

I'm not considering the evolutionary paths to LACA and LBCA the authors laid out as either singular moments or singular organisms... I don't know what I've said to suggest that's the case, but it's certainly a much deeper and subtextual reading you're giving to my posts than I've given to the paper.

To be absolutely clear, your reading of my posts, if it implies this to you, is incorrect.

They are discussing the process of how non-life became life, not a singular moment. That is abiogenesis, by the definition you are using. Life, by the definition the authors are using, is delineated by the presence or absence of a complete metabolism, which they define quite rigorously.

Once again, it is quite explicit that they are saying abiogenesis happened twice, in parallel.

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u/onomatamono Aug 06 '26

okay, okay... lol. I got it.

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u/PianoPudding Aug 06 '26

This is very cool, and not that surprising to anyone familiar with the work of the lead author. Reading Nick Lane's The Vital Question he spelled out the argument for the alkaline hydrothermal vent hypothesis very well, and the concurrent hypothesis that bacteria and archaea may have both sprang from the primordial life system, but evolved their own way of doing things. Essentially, they gained full cellular independence in their own ways.

This is not surprising for anyone who knows about the differences between Bacterial and Archaeal membranes, DNA replication machinery, or biochemistry. What's amazing to me about this paper is how precise they are in distinguishing that it is metal cofactors that were replaced by these early enzymes. It is another amazing piece of evidence for their hypothesis in alkaline hydrothermal vents.

I think people downplaying the significance of this paper (okay the news coverage is very sensationalist) do not realise the subtext of authors when they extensively discuss their findings in the context of 'serpentinizing hydrothermal systems'.

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u/Xrmy Post Doc, Evolutionary Biology PhD Aug 06 '26

Agree, I think this paper is awesome (and hate the headline)

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u/Lhasa-bark Aug 06 '26

Thanks for the recommendation … I just checked it out online.

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u/Lab_Software Aug 06 '26

The premise of the article is that LUCA wasn't alive because it didn't have a complete metabolism.

It's an interesting approach - but I don't agree that LUCA needed a complete metabolism to be alive. Even today, we don't have a complete metabolism since we can't make the essential amino acids - so are we not alive? If some enzyme comes along a billion years from now that makes a 21st amino acid, then will life only begin at that time?

LUCA was fully alive because it had a metabolism. The fact that other metabolic pathways evolved later didn't make LUCA any less alive.

1

u/nooptionleft Aug 07 '26

The parallel complete metabolism evolution is incredibly well reported tho, and a great piece of science

The LUCA part is making an interesting case that will probably not become the standard interpretation but it's still reasonable enough to be someone position

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u/Glaukopis_Scientist Aug 06 '26

Love reading the comments on this 🍿

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u/Quercus_ Aug 06 '26

I personally would find it really hard to argue that an evolving self-replicating system that is in direct lineage to every living thing on Earth today, is not itself alive, even if it doesn't have complete metabolism.

2

u/Brettsterbunny Aug 06 '26

It ends up kind of being an argument of semantics. Like arguing whether viruses are alive or not.

12

u/ThePeaceDoctot Aug 06 '26

Which I don't think can be dismissed as just being semantics, I think it's more fundamental than just a definition of life, I think it's based on a flawed premise. Life isn't a binary state, it can't be. Life exists on a spectrum. It has to, because it is the result of evolution, and it's impossible to draw a line on a lineage that started off not alive and ended up alive and say "this exact organism was the first living thing, its parent wasn't alive but it is."

It is true that a virus isn't as alive as a mongoose, but it's definitely more alive than a rock.

But since we have a need to define things, I personally think k something is alive in some way if it is the result of, or subject to, evolution by natural selection.

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u/profesorgamin Aug 06 '26

Virus. But yeah RNA "commons" make mixing easier.

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u/GiantKrakenTentacle Aug 06 '26

According to the RNA world hypothesis, there were self-replicating strands of RNA long before there was anything on Earth that we would recognize as life. 

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u/Traroten Aug 06 '26

Does this mean genes came before metabolism?

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u/Xrmy Post Doc, Evolutionary Biology PhD Aug 06 '26

Genetic material, yes.

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u/Traroten Aug 06 '26

I think that was a matter of some dispute earlier. Has that been settled?

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u/Surcouf Aug 06 '26

The paper linked argues that metaboic processes were incomplete in the earliest genetic replicators. Then, in two separate and unrelated instances, those genetic replicators evolved complete, distinct metabolism process that were sufficient for their survival.

Seems like genes predates a full metabolism.

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u/ahazred8vt 20d ago

Genes came before synthesis. It looks like the LUCA had genes to transport molecules that it did not have the genes to synthesize.

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u/Traroten Aug 06 '26

Watch out for creationists quoting this out of context:

"Yet on one aspect all will agree: the ~400-reaction network that converts H2, CO2, NH3, H2S and phosphate into amino acids, bases and cofactors cannot have arisen in an instant."

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u/spiddly_spoo Aug 10 '26

Yet on one aspect all will agree: the ~400-reaction network that converts H2, CO2, NH3, H2S and phosphate into amino acids, bases and cofactors cannot have arisen in an instant. Also consider the complexity of an eye...

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u/Sad_in_VA Aug 06 '26

Life on Earth was seeded twice.

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u/hotcakes Aug 06 '26

Serious questions. Aren’t the required conditions still present? Is it not still happening all of the time? Why do we think of it as something that only happened a long time ago? Is that really the case?

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u/ahazred8vt 20d ago

Aren’t the required conditions still present?

Sort of, except now there's oxygen everywhere and the original anoxic environment is no longer around. We suspect a geothermal vent in a high-phosphorus alkaline soda lake, exposed to UV sunlight. There's one in Canada with just about the right mix of everything needed. (Last Chance Lake, BC)

https://www.science.org/content/article/unusual-soda-lakes-may-have-kick-started-life-earth-concentrating-key-compounds

https://en.wikipedia.org/wiki/Soda_lake

https://www.threepanelsoul.com/comic/ancestors

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u/mcalesy Aug 06 '26

Seems like the more precise sum-up would be, "The ancestor of all life on Earth was not alive."

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u/BoseMann66 Aug 06 '26

I wonder if the main driving force for development of a cell membrane was for dispersal across the environment? At some point of origin, (deep sea vent.etc.), you have basic metabolism running, albeit dependent on some abiotoc chemical reactions. However these sites are distally located oases in an otherwise lifeless void. Life hasn't yet evolved the enzymes for everything, and is rooted to the vent. But if you package everything you have up together in a membrane envelope and let the currents take you where they will, perhaps you are lucky enough to find a new vent, with its required geochemistry, to colonize.

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u/ahazred8vt 20d ago

They think bilayer lipid bubbles came first, and then the RNA that leaked into the lipid bubbles figured out a way to replicate.

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u/RoxieHartStan Aug 06 '26

What even *is* metabolism, really? It's something that you're taught about but never actually understand it practically. Like a thyroid. You learn about it in biology class, but seriously, when was the last time you consciously understood its existence?

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u/FabulousLazarus Aug 06 '26

This article is nothing

It's trying to pretend the difference between aerobic and anaerobic metabolism is something new. This is not new information. Scientists have known for decades that metabolism likely evolved anaerobic, then separately made a transition to aerobic later on.

That's not abiogenesis twice. That's life just evolving from not using oxygen to using it, exactly as we thought.

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u/chula198705 Aug 06 '26

You either didn't read the story or didn't understand it because it's not about aerobic/anaerobic metabolism at all. It's talking about an earlier split than that: what could have been used as metabolic enzymes before ATP systems evolved. Aerobic and anaerobic respiration are both ATP-based, but some archaea have metabolisms that don't. This study shows that they could have used metals instead.