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This theory is called RNA-peptide coevolution, [114] or the Peptide-RNA world, and offers a possible explanation for the rapid evolution of high-quality replication in RNA (since proteins are catalysts), with the disadvantage of having to postulate the coincident formation of two complex molecules, an enzyme (from peptides) and a RNA (from ...
In the eocyte hypothesis, the organism at the root of all eocytes may have been a ribocyte of the RNA-world. For cellular DNA and DNA handling, an "out of virus" scenario has been proposed: storing genetic information in DNA may have been an innovation performed by viruses and later handed over to ribocytes twice, once transforming them into bacteria and once transforming them into archaea.
This difference between protein and ribonucleoprotein catalysts can be explained by extending the RNA world theory. The older RNA molecules were originally self-catalyzed through ribozymes, which evolved the assistance of proteins to form RNP. Thereafter, the newer DNA molecule used only the more efficient protein processes from the start. Thus ...
This concept is known as the RNA world hypothesis. According to this hypothesis, the ancient RNA world transitioned into the modern cellular world via the evolution of protein synthesis, followed by replacement of many cellular ribozyme catalysts by protein-based enzymes.
Kandler's pre-cell theory is supported by Wächtershäuser. [64] [65] In 1998, Carl Woese, based on the RNA world concept, proposed that no individual organism could be considered a LUCA, and that the genetic heritage of all modern organisms derived through horizontal gene transfer among an ancient community of organisms. [66]
The RNA world hypothesis describes an early Earth with self-replicating and catalytic RNA but no DNA or proteins. [172] Many researchers concur that an RNA world must have preceded the DNA-based life that now dominates. [173] However, RNA-based life may not have been the first to exist.
RNA can also act as a hereditary molecule, which encouraged Walter Gilbert to propose that in the distant past, the cell used RNA as both the genetic material and the structural and catalytic molecule rather than dividing these functions between DNA and protein as they are today; this hypothesis is known as the "RNA world hypothesis" of the ...
In the late 1960s, Orgel proposed that life was based on RNA before it was based on DNA or proteins. His theory included genes based on RNA and RNA enzymes. [17] This view would be developed and shaped into the now widely accepted RNA world hypothesis. Almost thirty years later, Orgel wrote a lengthy review of the RNA World hypothesis. [18]