The emergence of “information-coding properties”:
According to a new concept by LMU chemists led by Thomas Carell, it was a novel molecular species composed out of RNA and peptides that set in motion the evolution of life into more complex forms…Ludwig Maximilian University of Munich, “The origin of life: A paradigm shift” at Phys.org (May 12, 2022)
It’s a new twist on the RNA world hypothesis:
“The RNA world idea has the big advantage that it sketches out a pathway whereby complex biomolecules such as nucleic acids with optimized catalytic and, at the same time, information-coding properties can emerge,” says LMU chemist Thomas Carell. Genetic material, as we understand it today, is made up of double strands of DNA, a slightly modified, durable form of macromolecule composed of nucleotides.
However, the hypothesis is not without its issues. For example, RNS is a very fragile molecule, especially when it gets longer. Furthermore, it is not clear how the linking of RNA molecules with the world of proteins could have come about, for which the genetic material, as we know, supplies the blueprints. As laid out in a new paper published in Nature, Carell’s working group has discovered a way in which this linking could have occurred.Ludwig Maximilian University of Munich, “The origin of life: A paradigm shift” at Phys.org (May 12, 2022)
The new proposal:
According to the new theory, a decisive element at the beginning was the presence of RNA molecules that could adorn themselves with amino acids and peptides and so join them into larger peptide structures. “RNA developed slowly into a constantly improving amino acid linking catalyst,” says Carell. This relationship between RNA and peptides or proteins has remained to this day. The most important RNA catalyst is the ribosome, which still links amino acids into long peptide chains today. One of the most complicated RNA machines, it is responsible in every cell for translating genetic information into functional proteins. “The RNA-peptide world thus solves the chicken-and-egg problem,” says Carell. “The new idea creates a foundation upon which the origin of life gradually becomes explicable.”Ludwig Maximilian University of Munich, “The origin of life: A paradigm shift” at Phys.org (May 12, 2022)
Sure it works if we are not looking for something simple enough to have evolved randomly by Darwinian processes. Something else must underlie the drive for complexity (“information-coding properties”) described here.
The paper is open access.