Structure that links amino acids suggests that early organisms could have been based on an RNA–protein mix.
Chemists say they have solved a crucial problem in a theory of life’s beginnings, by demonstrating that RNA molecules can link short chains of amino acids together.
Credit: Omikron/Science Photo Library
The findings, published on 11 May in Nature1, support a variation on the ‘RNA world’ hypothesis, which proposes that before the evolution of DNA and the proteins it encodes, the first organisms were based on strands of RNA, a molecule that can both store genetic information — as sequences of the nucleosides A, C, G and U — and act as a catalyst for chemical reactions.
The discovery “opens up vast and fundamentally new avenues of pursuit for early chemical evolution”, says Bill Martin, who studies molecular evolution at Heinrich Heine University Düsseldorf in Germany.
Chemists say they have solved a crucial problem in a theory of life’s beginnings, by demonstrating that RNA molecules can link short chains of amino acids together.
The findings, published on 11 May in Nature1, support a variation on the ‘RNA world’ hypothesis, which proposes that before the evolution of DNA and the proteins it encodes, the first organisms were based on strands of RNA, a molecule that can both store genetic information — as sequences of the nucleosides A, C, G and U — and act as a catalyst for chemical reactions.
The discovery “opens up vast and fundamentally new avenues of pursuit for early chemical evolution”, says Bill Martin, who studies molecular evolution at Heinrich Heine University Düsseldorf in Germany.
“This is a very exciting finding,” says Martin, “not only because it maps out a new route to RNA-based peptide formation, but because it also uncovers new evolutionary significance to the naturally occurring modified bases of RNA.” The results point to an important part played by RNA at the origins of life, but without requiring RNA alone to self-replicate, Martin adds.
To show that this is a plausible origin of life, scientists must complete several further steps. The peptides that form on the team’s RNA are composed of a random sequence of amino acids, rather than one determined by information stored in the RNA. Carell says that larger RNA structures could have sections that fold into shapes that ‘recognize’ specific amino acids at specific sites, producing a well-determined structure. And some of these complex RNA–peptide hybrids could have catalytic properties, and be subject to evolutionary pressure to become more efficient. “If the molecule can replicate, you have something like a mini organism,” says Carell.
Nature
It is apparent from the article that researcher intervention was critical in obtaining the reported outcome. Also, the pre-existence of complex, functional biomolecules is assumed (RNA itself, and ribosomes consisting of RNA segments and proteins). Evolution is mentioned several times as a means of guiding the nascent process into a fully self-replicating “mini organism.” Wishful thinking cannot overturn the information-barrier challenges involved in producing functional, self-replicating biomolecular machinery.
I think the following articles do a good job of highlighting just how detached from reality these speculations on the naturalistic origin of life are.
Just how far out of thermodynamic equilibrium is a ‘simple’ cell?
And 10^12 bits is equivalent to about 100 million pages of Encyclopedia Britannica,
And seeing that the information content of just a single protein is far beyond chance to ever explain,
,, then obviously believing that chance can possibly explain a (very) simple cell with approximately 400 genes is exponentially worse
Here is a beautiful quote by Dr. Tour
Verse:
An assumption of a non-dissipating molecule appearing at one end and an assumption of replication eventually appearing at the other end is a hypothesis with too much lead in the saddle bag to run far.
On the other hand, it might lead to a new fabric as shiny as silk and warm as wool and. can take dyes better than cotton – that’s a possibility too.
And the RNA can form in basaltic glass:
https://phys.org/news/2022-06-scientists-breakthrough-life-earthand-mars.html
This is interesting. However, the ribosome uses RNAs for making proteins. They are housed in a protein structure, but the RNAs are the catalyst. The point being we already knew that RNAs could catalyze peptide bonds. This just shows that the protein structure of the ribosome isn’t required for that reaction.
:))) This is not “breakthrough” is the same old magical thinking(emergence of meaningful code from chemicals and by chemicals ) that life must have emerged from matter but is too difficult for science to prove that today but tomorrow will be proven. Guaranteed. 🙂 Well Mr. Scientist if is too difficult to prove a hypothesis why do you claim that is true ? The unproven ‘RNA world’ hypothesis is based on other never proved claim that life origin is materialistic. We have a chain of unproved assumptions that are considered true by default just because some people claim that to be true? This is not science is religion.
Upright Biped
Upright Biped
Upright Biped
This doesn’t have anything to do with semiotics, Fred. And you don’t understand the argument, anyway.
Absolutely right, ET. That stopped clock again! 😉
Perhaps decide first what the issue is, have an argument, then you may be in a position to judge.
Upright Biped
Upright Biped
Upright Biped
More developments at Tokyo University:
https://www.quantamagazine.org/in-test-tubes-rna-molecules-evolve-into-a-tiny-ecosystem-20220505
Upright Biped
Upright Biped
Upright Biped
Fred:
I know what the issue is. You aren’t interested in any argument. And you definitely aren’t in any position to judge. Semiotics is the issue, Fred. Not one thing in this thread deals with semiotics.
RNAs producing more RNAs is not semiotics. When mRNA codons REPRESENT amino acids, then you have semiotics. When you have a ribosome that puts out a protein from a mRNA input, you have semiotics.
So, the ISSUE is how does physics and chemistry produce semiotics? No one knows.
Here, Upright Biped.
Fred- calm down. It’s obvious that you don’t understand the argument. mRNA is neither a replicator nor a catalyst. It is a coded information carrier. It is the symbol.
What is wrong with you? Why do you pick a war of wits and come unarmed?