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Origin of Life. Big news?

Meadmaker

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Meadmaker
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Apr 27, 2004
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This seems like pretty big news:

https://www.studyfinds.org/missing-link-origins-of-life/


Although I'm a little bit skeptical, just because it isn't making really big headlines. It seems, though, that this is the first case I've read about where a naturally generated replicator was produced. I don't have enough knowledge of the subject to say this is a really big deal, or this is no big deal, but it seems like it could be a pretty big deal to me.

An excerpt:

"Matsuo and Kurihara created a non-living building block capable of replicating itself using amino acids (the basic components of proteins) which acted as the progenitor. The researchers then applied water (at normal temperature) to the molecules, which then joined together and formed proteins under standard pressure."

Sounds significant to me.
 
Meadmaker said:
This seems like pretty big news:

https://www.studyfinds.org/missing-link-origins-of-life/


Although I'm a little bit skeptical, just because it isn't making really big headlines. It seems, though, that this is the first case I've read about where a naturally generated replicator was produced. I don't have enough knowledge of the subject to say this is a really big deal, or this is no big deal, but it seems like it could be a pretty big deal to me.

An excerpt:

"Matsuo and Kurihara created a non-living building block capable of replicating itself using amino acids (the basic components of proteins) which acted as the progenitor. The researchers then applied water (at normal temperature) to the molecules, which then joined together and formed proteins under standard pressure."

Sounds significant to me.
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Yes interesting. Of course man can manufacture compounds that could not occur naturally so this does not mean life must be elsewhere.
 
"The creation of organic molecules from inorganic sources"... Plants do it all the time.
 
The creation of organic molecules is not the significant part of the article.

It's the replication that matters.


Or at least.....it appears to me to matter. I read the paper's abstract and there are too many chemistry references for me to know if this is all that significant. It looks fairly significant to me, but I'm not sure about the natural occurrence fo the chemicals in question to say much about whether this could actually be pointing to a theory about the origni of life.

In other words, is it plausible that the reactions described in the paper were actually a step in the development of the first cell-like living entity, or is it too contrived? Could the specific components used have ever occurred in nature?? If that were the case, then it would still be an interesting experiment, demonstrating a class of replication, but not something that could plausibly have been an actual step in the actual development of life from non-life.
 
In a nutsa... err... shell:

Previously the best hypothesis was basically "RNA world", and it was demonstrated than (in a world without much oxygen) a certain RNA sequence can replicate itself, and the copies can replicate further, and so on. Of course, it wasn't clear how it got from RNA just replicating itself to a ribosome, that is a machine consisting of RNA and proteins, that transcribes stuff into proteins, some of which then can copy RNA or DNA or between the two.

E.g., even RNA viruses come not with a RNA piece that just copies RNA, but with the code for the ribosome to produce a protein called RNA transcriptase, which then copies the virus RNA. Or a protein called reverse transcriptase, which copies the virus RNA to DNA, which then is copied by your cells to RNA again, which then is used by the ribosome to assemble the proteins.

So, anyway, if you have RNA copying RNA, where do proteins even start to enter that process? And how come none of that RNA copying RNA was preserved anywhere?

So what is different about what this guys did?

Well, instead of starting from the RNA, they started from a protein which can copy itself or other proteins.

NB, this means it can assemble proteins from aminoacids, according to some pattern, in this case another protein. Ah-ha, now we actually have something that can assemble proteins. That was a missing part of the previous puzzle.

Apparently it can even incorporate DNA or RNA pieces into itself, to improve its survivability. Meaning you already have evolution. Basically pointing in the direction that it could evolve into an actual ribosome. In fact, it pretty much IS a proto-ribosome. Sorta the alpha version of a ribosome.
 
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Reports of the first self replicating molecule being discovered are like reports of Voyager leaving the solar system. It all depends on what definition of solar system you are using and whether the reporter writing the story knows about any of the earlier reports of Voyager leaving the solar system. Or even knows which Voyager they are writing about.
 
RecoveringYuppy said:
Reports of the first self replicating molecule being discovered are like reports of Voyager leaving the solar system. It all depends on what definition of solar system you are using and whether the reporter writing the story knows about any of the earlier reports of Voyager leaving the solar system. Or even knows which Voyager they are writing about.
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Can you direct us to the earlier reports of the first self replicating molecule being discovered? The abstract reads as follows:

The hypothesis that prebiotic molecules were transformed into polymers that evolved into proliferating molecular assemblages and eventually a primitive cell was first proposed about 100 years ago. To the best of our knowledge, however, no model of a proliferating prebiotic system has yet been realised because different conditions are required for polymer generation and self-assembly. In this study, we identify conditions suitable for concurrent peptide generation and self-assembly, and we show how a proliferating peptide-based droplet could be created by using synthesised amino acid thioesters as prebiotic monomers. Oligopeptides generated from the monomers spontaneously formed droplets through liquid–liquid phase separation in water. The droplets underwent a steady growth–division cycle by periodic addition of monomers through autocatalytic self-reproduction. Heterogeneous enrichment of RNA and lipids within droplets enabled RNA to protect the droplet from dissolution by lipids. These results provide experimental constructs for origins-of-life research and open up directions in the development of peptide-based materials.
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Now I'm no microbiologist, but this sounds novel to me.
 
Well, it doesn't seem like the secret (to what?) to life (itself?) itself, but it sure looks like a step along the way. Fairly significant, but not earth - shaking.

It got into the big journal.
 
I just don't know if a thioester is something you might find hanging about a volcanic vent or on a beach or wherever life might get started naturally. I'm not really up on thioesters.



(As I'm sure most readers already know, I looked up what one was when I saw the abstract, and after reading it, I still wouldn't really know. Fortunately, I'm just auditing the class, so it won't be on the test for me.)
 
arthwollipot said:
Can you direct us to the earlier reports of the first self replicating molecule being discovered? The abstract reads as follows:

Now I'm no microbiologist, but this sounds novel to me.
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Novel? It might be novel. If you define anything narrowly enough, no True Scotsman style, you can make anything novel. I'd venture to say that every replicator we already know about is novel. I'd need to know how different something has to be for you to qualify as novel to answer that.

Salt crystals are self replicating. If I specify that the self replicator has to be a cubic lattice of a particular molecular weight I can make the formation of salt a novel example of self replication. So that put's the earliest reports back in to pre-history.

Want a more complicated modern example: try this: Autocatalytic self-replicating micelles as models for prebiotic structures Does this meet your requirement of novelty? It's just the first thing that popped up in a google search of the single word "autocatalytic".

So can you specify what it takes to be "novel" to you?

The OP says "naturally generated replicator". That's way too vague to judge novelty. Salt qualifies.

I realize that crossbow didn't cite the best example, but if you dig through all the various uses of variations on "replicate" in that wikipedia article there were actual replicators already cited. Did those meet whatever degree of novelty you're looking for?
 
I used the word "novel" because I was not aware of a replicator that both spontaneously self-assembles and catalyses its own replication. Your paper describes the spontaneous formation of micelles, which for want of a better word are "passive" structural formations, while the new one describes the spontaneous formation of peptides, which are "active" components of biology. I think that's the difference.
 
arthwollipot said:
I used the word "novel" because I was not aware of a replicator that both spontaneously self-assembles and catalyses its own replication. Your paper describes the spontaneous formation of micelles, which for want of a better word are "passive" structural formations, while the new one describes the spontaneous formation of peptides, which are "active" components of biology. I think that's the difference.
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OK. Afraid I don't get either of those distinctions. Sounds like No True Scotsman to me, but you do you.

What do you think of this: https://www.nature.com/articles/s41467-017-00849-1

That was the third hit on google just by adding "peptide" to my earlier search.
 
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RecoveringYuppy said:
OK. Afraid I don't get either of those distinctions. Sounds like No True Scotsman to me, but you do you.

What do you think of this: https://www.nature.com/articles/s41467-017-00849-1

That was the third hit on google just by adding "peptide" to my earlier search.
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And here we start to hit the limit of my understanding of molecular biochemistry. So sorry, I don't know. It's possible that I was not correct about this being something novel, even though the paper itself says that it is. I find it hard to believe that the authors of the paper simply didn't know that they were merely repeating work that was done four years previously. That's the kind of thing that gets picked up in a literature review even before you start.

Knowing what I do now, I might answer the OP thusly:

Yes, it appears to me that this is big news. But it is still only a small step in the process of understanding abiogenesis. It will go into the annals of knowledge, from which further knowledge will be built.
 
arthwollipot said:
It's possible that I was not correct about this being something novel, even though the paper itself says that it is.
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It is novel. Everything can be novel if you define it narrowly enough.

arthwollipot said:
I find it hard to believe that the authors of the paper simply didn't know that they were merely repeating work that was done four years previously. That's the kind of thing that gets picked up in a literature review even before you start.
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I have no reason to suspect they are repeating earlier work. Neither of the two articles I cited or saw on Google was a repeat of this study.

This study is likely a novel example of a replicator. But it's not likely to qualify as the first unless you choose a very specific definition.
 
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