concept

RNA world

The hypothesis that there was a stage at which RNA both carried genetic information and catalysed its own chemistry, before DNA and protein enzymes. The supporting evidence is real: RNA genuinely does catalyse, the ribosome's catalytic core is RNA, and universal energy carriers like ATP and NAD are ribonucleotide derivatives. But it remains the leading hypothesis rather than established fact: ribose is fragile, and nobody has demonstrated RNA copying itself unaided.