Topic: RNA world

Mariana Kneppers, Mason Wakley and Neil Withers discuss two questions about genetic information. They examine AlphaGenome, a machine learning model designed to predict molecular effects of DNA variants across long sequences, and consider its potential use in genetics research. The episode then turns to the RNA world hypothesis: the proposal that RNA-based systems preceded DNA genomes and cells during the early history of life. The discussion links contemporary tools for studying the genome with chemical questions about life's beginnings.

Gerald Joyce explores attempts to reconstruct features of RNA-based life in the laboratory. Under the RNA world hypothesis, early organisms used RNA to store information and catalyze replication before the emergence of DNA genomes. Directed evolution has produced RNA enzymes that copy diverse templates, synthesize structured and catalytic RNAs, and amplify short templates in an RNA-catalyzed analogue of the polymerase chain reaction. A variant can make DNA from an RNA template, suggesting a possible route between RNA and DNA genomes. Joyce also describes cross-chiral enzymes that synthesize RN