BIO In the literature: partially resolved

Sustained exponential self-replication by a polymerase ribozyme

In plain words

In the RNA-world idea, early life used RNA both as genes and as enzymes, which requires an RNA able to copy itself. In 2026 a 45-nucleotide RNA enzyme copied itself and its partner strand, but too slowly and too inaccurately for its numbers to keep growing over many rounds.

Precise statement

A polymerase ribozyme of length $L$ must synthesize complete copies of itself and of its complementary strand with per-nucleotide fidelity $q$ satisfying $L(1 - q) < \operatorname{ln}(\sigma)$ (Eigen error threshold; $\sigma$ = selective advantage of the correct sequence), at yields that allow exponential growth over repeated cycles that include strand separation. QT45, a 45-nucleotide ribozyme (Gianni and co-workers, Science 2026), synthesizes its complementary strand from a random triplet pool at $q = 0.941$ and a copy of itself from defined triplet substrates, each at about 0.2% yield in 72 days in eutectic ice. Answer: yes or no, with a demonstrated system showing sustained exponential amplification of both strands over many rounds without defined oligomer feeds.

What would settle it

Demonstration of sustained exponential amplification of a ribozyme by its own copying activity over many rounds, with sequence fidelity measured by deep sequencing.

Status in the literature

Unverified note

In 2026 the 45-nucleotide ribozyme QT45 synthesized its complementary strand ($94.1\%$ fidelity) and a copy of itself at about $0.2\%$ yield in $72\,\mathrm{days}$; sustained self-replication has not been reported (Science, doi 10.1126/science.adt2760).