Evolution of a core ribosomal innovation in octopus.

Much of biology focuses on how genetic changes mediate new functions, but less attention is given to adaptations within the ancient molecular machines that execute the central dogma. Octopuses exhibit complex nervous systems and sophisticated behaviors that rival vertebrates but via an entirely divergent evolutionary history. Here, we serendipitously discovered that octopus ribosomes contain a structural break in the core ribosomal RNA that is unique among all animals. This break site enhances translation fidelity to reduce miscoding and subsequent protein aggregation, even when engineered into evolutionarily distant bacterial ribosomes. Furthermore, high-fidelity translation by octopus ribosomes supports proteomic stability during extensive RNA editing observed in cephalopods, suggesting synergy between distinct non-canonical modes of gene regulation. This adaptation emerged in recently derived octopuses with expanded nervous systems, thereby revealing a mechanism that could broadly support the evolution of novel organismal traits.