Re: Modeling the origins of life: New evidence for an 'RNA World'

Pro Plyd wrote:

https://phys.org/news/2024-03-life-evidence-rna-world.html

....
But how did all of this begin? In the origins of
life, long before cells and proteins and DNA,
could a similar sort of evolution have taken
place on a simpler scale? Scientists in the
1960s, including Salk Fellow Leslie Orgel,
proposed that life began with the "RNA World,"
a hypothetical era in which small, stringy RNA
molecules ruled the early Earth and established
the dynamics of Darwinian evolution.

New research at the Salk Institute now provides
fresh insights on the origins of life, presenting
compelling evidence supporting the RNA World
hypothesis. The study, published in Proceedings
of the National Academy of Sciences (PNAS),
unveils an RNA enzyme that can make accurate
copies of other functional RNA strands, while
also allowing new variants of the molecule to
emerge over time. These remarkable capabilities
suggest the earliest forms of evolution may have
occurred on a molecular scale in RNA.

The findings also bring scientists one step
closer to re-creating RNA-based life in the
laboratory. By modeling these primitive
environments in the lab, scientists can
directly test hypotheses about how life may
have started on Earth, or even other planets.
....

https://www.pnas.org/doi/10.1073/pnas.2321592121
RNA-catalyzed evolution of catalytic RNA

Abstract
An RNA polymerase ribozyme that was obtained
by directed evolution can propagate a functional
RNA through repeated rounds of replication and
selection, thereby enabling Darwinian evolution.
Earlier versions of the polymerase did not have
sufficient copying fidelity to propagate
functional information, but a new variant with
improved fidelity can replicate the hammerhead
ribozyme through reciprocal synthesis of both
the hammerhead and its complement, with the
products then being selected for RNA-cleavage
activity. Two evolutionary lineages were
carried out in parallel, using either the prior
low-fidelity or the newer high-fidelity
polymerase. The former lineage quickly lost
hammerhead functionality as the population
diverged toward random sequences, whereas the
latter evolved new hammerhead variants with
improved fitness compared to the starting RNA.
The increase in fitness was attributable to
specific mutations that improved the
replicability of the hammerhead,
counterbalanced by a small decrease in
hammerhead activity. Deep sequencing analysis
was used to follow the course of evolution,
revealing the emergence of a succession of
variants that progressively diverged from the
starting hammerhead as fitness increased. This
study demonstrates the critical importance of
replication fidelity for maintaining heritable
information in an RNA-based evolving system,
such as is thought to have existed during the
early history of life on Earth. Attempts to
recreate RNA-based life in the laboratory must
achieve further improvements in replication
fidelity to enable the fully autonomous
Darwinian evolution of RNA enzymes as complex
as the polymerase itself.

Some complaints have been lodged about a prior response
to this post. Generally I would disregard things from that
author but as I read this first I have a slightly different
take. Specifically, if I were given the above as a referee
I would have asked them to substitute "enabling natural selection" for "enabling Darwinian evolution." If you ask "why?", I respond it should be obvious. Natural selection is a more obvious reference to a process of refinement by differential reproductive success. That in context 'Darwinian
evolution' must of course mean the same thing is true, but experience tells me that it is also a term where many misreading
begin, supported by the evidence in this thread.
In fact I recoiled at a few other points in the science journalism
reporting on the article as well, even if they are minor. (Darwinian evolution is used in the original). Of course science journalism is hard, and there should be
a place for articles targeted towards a more sensible audience.
Having to write 'defensively' all the time would be a heavy
burden. But ultimately that's all the better reason to avoid
getting sloppy in the primary literature and littering it with
less appropriate terminology like __Darwinian_Evolution__.