# RNA > **Machine-Evolution Nexus:** [[articles/Digital Darwinism and the Invisible World of Machine Evolution|Digital Darwinism and the Invisible World of Machine Evolution]] places this node within the history and governance of substrate-independent evolution. **Domain:** Molecular Biology / Origins / Heredity **Doc Type:** Canonical Wiki Node **Maturity:** Developed ## Definition RNA is a nucleic-acid polymer that can carry sequence information and perform structural, regulatory and catalytic functions. ## Nexus Context RNA’s combined informational and catalytic capacities make it central to origin-of-life and major-transition discussions, while modern cells use RNA throughout gene expression. ## Evidence Boundary The RNA-world hypothesis is a research program with unresolved chemical and historical questions, not an observed record of life’s exact beginning. ## Relationships [[wiki/Nucleic Acid|Nucleic Acid]], [[wiki/DNA|DNA]], [[wiki/Central Dogma of Molecular Biology|Central Dogma of Molecular Biology]], [[wiki/Major Evolutionary Transitions|Major Evolutionary Transitions]] ## Sources / Provenance - Molecular-biology texts; origin-of-life literature.