The Ribosome and the RNA World. The RNA World is a broadly accepted model for the origin of life on earth. However, the translation system presents fundamental challenges to RNA World models. We can find no basis for preservation of the ribosome as
The Ribosome and the RNA World. The RNA World is a broadly accepted model for the origin of life on earth. However, the translation system presents fundamental challenges to RNA World models. We can find no basis for preservation of the ribosome as a ribozyme, when other information transducing ribozymes of the RNA World were replaced by protein analogs. Ribozyme RNA polymerases, the defining catalytic systems of the RNA World, have gone extinct and were erased from the phylogenetic record. Yet the ribosome remains, universal to all life. An entire metabolic system based on ribozymes was extinguished. Yet the catalytic core of the ribosome is immutable. The mechanism of catalysis of the ribosome signals origins in a chemical rather than biological milieu. Did biology really change it's mind? Or was the cooperative relationship between protein and RNA, centered on the ribosome, built in from the beginning? For more information, please see Bowman, Hud, and Williams, J. Mol. Evolution, 2015.