A Peptide–Nucleic Acid Replicator Origin for Life. (May 2020)

• Record Type: Journal Article
• Authors: Piette, Bernard M.A.G.; Heddle, Jonathan G.
• Is Part Of: Trends in ecology & evolution. Volume 35:Number 5(2020)
• Page Start: 397
• Page End: 406
• Publication Date: 2020-05
• Subjects: abiogenesis -- RNA world -- stereochemical theory -- early earth -- hypercycle; Ecology -- Periodicals; Evolution (Biology) -- Periodicals; 576.8
• DOI: 10.1016/j.tree.2020.01.001
• Languages: English
• ISSNs: 0169-5347

Abstract

Abstract : Evolution requires self-replication. But, what was the very first self-replicator directly ancestral to all life? The currently favoured RNA World theory assigns this role to RNA alone but suffers from a number of seemingly intractable problems. Instead, we suggest that the self-replicator consisted of both peptides and nucleic acid strands. Such a nucleopeptide replicator is more feasible both in the light of the replication machinery currently found in cells and the complexity of the evolutionary path required to reach them. Recent theoretical and mathematical work supports this idea and provide a blueprint for future investigations. Highlights: The first ancestor to all life was a self-replicating entity capable of evolving but must have been much simpler than a cell; that is, a molecular replicator. Recent work on RNA polymerase ribozymes supports the view that the molecular replicator was made of RNA, and no other molecule was required (the RNA World). The RNA World is challenged by the fact that a self-replicating RNA polymerase ribozyme has yet to be demonstrated and that little evidence for its existence is seen in life today as well as problems in how the transition from RNA-only to RNA–protein world could have occurred. A molecular replicator with two components –RNA and peptide – overcomes these problems and may be a better fit.