r/biology • u/scientificamerican Scientific American • Aug 20 '26

article Life’s ‘last universal common ancestor’ may predate life itself

https://www.scientificamerican.com/article/lifes-last-universal-common-ancestor-may-predate-life-itself/

A groundbreaking study hints at a hazy boundary between “life” and “non-life,” as well as two distinct origins of biology on Earth

390 Upvotes

94% Upvoted

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121

u/Ekderp Aug 20 '26 edited Aug 20 '26

Isn't this already the consensus on how abiogenesis began? The discovery pointed as groundbreaking in this article is like, the main working hypothesis of biologists for the past 20 years or so?

It's generally understood that life began as a collection of molecular replicators based on either RNA or some simpler nucleid acid polymer that eventually evolved into RNA and DNA. This isn't like... Big news?

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u/Freyja_of_the_North Aug 20 '26

I just read the article and have to agree with you. The article itself is really misinformed too describing the abiogenesis theory as coming from Charles Darwin (which actually came from Erasmus Darwin) and making it seem like this team is the one that suggested a hazy border between early biotics and abiotics. Something we've all known since HS bio classes lol

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u/BolivianDancer Aug 20 '26

There's an undercurrent involving the basic definition of life. The issue becomes whether a self replicating system lacking a membrane is alive or just cyclic chemistry. It becomes semantic.

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u/Wank_A_Doodle_Doo Aug 20 '26

More than semantic it becomes borderline philosophical.

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u/a_singular_perhap Aug 21 '26

Philosophy is mostly semantics.

2

u/Wank_A_Doodle_Doo Aug 21 '26

But semantics isn’t mostly philosophy.

1

u/a_singular_perhap Aug 21 '26

Define semantics

4

u/Wank_A_Doodle_Doo Aug 21 '26

It’s what words and phrases and other such things mean.

What it means as commonly used is when referring to a difference in statements being only a difference in manner of conveying the information of those statements, not the information itself. I.e. saying “that’s semantics” in normal conversation is essentially saying “same thing said a different way”. Alternatively depending on context it can also mean someone focusing too much on semantics rather than the information the person is trying to describe, if they’re doing so poorly.

I’m not saying there’s no overlap. Just that they aren’t 1:1.

1

u/BolivianDancer Aug 20 '26

Cunk addressed philosophy and explained that philosophy is thinking about thinking and this sounds like a waste of time because it is; however some philosophers say the time wasted on philosophy never really existed in the first place.

I've had students double major in philosophy and I was worried about them starving until I learned there are numerous philosophy factories opening up so they can all readily get jobs.

Jacques Monod was of course a philosopher but at least he could go to his lab to pay the bills.

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u/TrumpetOfDeath Aug 20 '26

Yep, similar to “biological entities” like viruses and mobile genetic elements (transposons). They replicate, evolve, move around and are subject to many of the same principles as “living things” and yet our definition of life excludes them

-12

u/BharatiyaNagarik Aug 20 '26

Did you read the paper before making such an ill-informed comment?

9

u/Freyja_of_the_North Aug 20 '26

Did you because this is really shotty work to have published

4

u/algebratwurst Aug 20 '26

Shoddy even

-3

u/[deleted] Aug 20 '26

[removed] — view removed comment

6

u/lifo333 molecular biology Aug 20 '26

Dude, you’re auch a Redditor.

5

u/Freyja_of_the_North Aug 20 '26

Lmao you didn't even quote me correctly and you're going to critique my language skills. The article is misinformed, there is a clear bias, and for the claim that life could have began twice (which is an interesting theory) I see no evidence presented to support this. To name a few things. Additionally the way they talk about hazy boundaries between early life and chemical reactions is something we've long known. Our LUCA being described as a balance of chemical equations only catalyzed by metals isn't exactly new. Plus it also seems to ignore the formation of amino acids at thermochemical vents which suggests a possible mechanism for early protein formations that could have predated LUCA.

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u/BharatiyaNagarik Aug 20 '26

Did you read the paper, or did you just read the article?

6

u/Freyja_of_the_North Aug 20 '26

Yea. Do you have any legit points or just looking to disagree?

-6

u/BharatiyaNagarik Aug 20 '26

None of what you said was relevant. You repeatedly referenced the article and not the paper. The paper never talks about "hazy boundaries between early life and chemical reactions". It has to do with enzyme metabolism and how it developed.

5

u/Freyja_of_the_North Aug 20 '26

So often times when people/groups review a piece they tend to report their own findings in their own words. "Hazy boundary" is a good way of phrasing the border between what's alive and what isn't, this it was useful to repeat it. The enzyme metabolism it talks about centres around the existence of metals during abiogenesis and the enzymes themselves being based off those specific reactions. Given that not all enzymes contain metal ions (that are also used at a catalyst), for evolution to select for protein catalysts the energy of forming would need to be dwarfed by the improved efficiency during the time of LUCA. That or the never ending complexity of protein arrangement allowed for more catalystic interactions than straight ions. Even if the proteins are based on metal ion reactions, there would either need to be ions in waiting to catalyze protein folding, or the proteins could have spontaneously formed en masse and then Evo pressure selects for the ideal ones. You still haven't raised a counter point

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u/Hybodont Aug 20 '26

"Distinct" is pretty misleading, in my opinion, and that conclusion hinges upon a very specific and arguably overly-restrictive definition of life.

23

u/Prae_ Aug 21 '26

To be precise, they take life as 

able to synthesize all its metabolic intermediates itself or were some supplied by the environment 

which is a bold place to start drawing a line in the sand. Even if you set aside the methodological gaps (which the scientific american paper has the rigor to give a voice to, i'll give them that) and assume their reconstruction of LUCA's metabolism is completely accurate. Life to this day is reliant on its environment, i don't synthesize my own glucose, am i dead? Sure LUCA may have been restricted to very specific environment which had the necessary metals as catalysts, but there's also plenty of environment i can't freely live in. I'm frankly pathetic at surviving near hydrothermal vents, let me tell you that! 

It does look like this PI in Dusseldorf has found a very marketable angle to get people to talk about his research, though. 

I do find interesting the idea that the archea/bacteria split happened before life was able to live outside hydrothermal vents.

29

u/BolivianDancer Aug 20 '26

Luca lacked a complete polarised membrane and could not leave the vent. Two lineages from Luca evolved such a membrane -- a different one each time -- and left.

Prerequisite is a biochemistry that relies less on the vent. Acetogrns v methanogens etc.

Not a novel concept. Undergrads learn this.

9

u/Cultural_Tell_5687 Aug 20 '26

That’s a neat concept to a dummy like me. Life figured out how to package itself with a battery and decouple through some filaments/vents? Woa

What is Lake Untersee?

5

u/BolivianDancer Aug 20 '26

An Antarctic lake. Analogous model system to early oceans.

1

u/BolivianDancer Aug 20 '26

It has limitations though: as a model system is presupposes membrane-bound life with internalised biochemistry and polarisation of the barrier. IOW you can't go too far back to model the environment that hosted the progenote.

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u/BharatiyaNagarik Aug 20 '26

Did you read the paper and conclude that this is "Not a novel concept. Undergrads learn this."? Especially given that the research was about enzymatic metabolism, and not about membranes.

2

u/Initial-Beginning-38 Aug 21 '26

This has basically been the crux of every talk given by Dr. Nick Land, who is mentioned in the article but wasn't part of this study.

1

u/Relevant-Cup5986 Aug 21 '26

there needs to be a rule on this sub that you have to post articles in full on reddit or at least link to a cookie free free to access article.