The Central Dogma

Crick named it deliberately badly. He later admitted he had misunderstood the word “dogma”—he thought it meant a bold assertion held without sufficient evidence, which is exactly what he intended, rather than an established belief beyond dispute. The mischief mattered because the central dogma was a bet, and bets can be lost. What the dogma actually stated—precisely—is that detailed sequence information cannot flow out of protein back into nucleic acid. Information passes from DNA to RNA to protein; it does not travel the reverse path. Within a decade, the discovery of reverse transcriptase showed that information can flow from RNA to DNA, against the expected direction. Crick’s formulation survived because it was precise enough to be repaired: the deep prohibition held even as one of the forward arrows proved reversible. The episode teaches the AI age its most durable methodological lesson: directionality in information systems is a property of a particular mechanism, not a law of information