![A symbiotic scenario for co-evolution of the ribosome and the replicase. Two variations of the scenario are depicted, whereby the peptidyltransferase center (PTC) and the replicase (REP) ribozymes are encoded by distinct (A) or the same (B) RNA molecule. The figure depicts three major stages of cellular evolution from the primordial RNA world (left) to the intermediate RNA-protein world (center) and the last universal cellular ancestor (LUCA, right). The major events occurring during each stage are briefly described in the corresponding information boxes at the bottom of the figure. -- [q-bio.PE]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-selfish.png?fit=1200%2C670&ssl=1)
[q-bio.PE]. The ribosome is responsible for protein synthesis in all cells, and is the largest energy consumer in the cell.
We propose that the ribosome originated as a mutualistic symbiont of an RNA-dependent RNA polymerase ribozyme, supplying peptides that enhanced replication. As life transitioned from the RNA to the RNA-protein world, autonomous replicators became irreversibly addicted to the ribosome for producing replication proteins.
Subsequent evolution is construed as a ribosomal takeover, whereby the ribosome evolved to consume most of the resources of the cell, while other cellular componentry ensured the propagation of the ribosome. Under this perspective, the ribosome is the ultimate biological selfish element.
Mart Krupovic, Eugene V. Koonin
Comments: 16 pages, 2 figures
Subjects: Populations and Evolution (q-bio.PE)
Cite as: arXiv:2602.23268 [q-bio.PE] (or arXiv:2602.23268v2 [q-bio.PE] for this version)
https://doi.org/10.48550/arXiv.2602.23268
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Submission history
From: Eugene Koonin
[v1] Thu, 26 Feb 2026 17:41:04 UTC (577 KB)
[v2] Fri, 27 Feb 2026 20:10:31 UTC (1,500 KB)
https://arxiv.org/abs/2602.23268
Astrobiology, Genomics,
