The James D. and Julia P. Morrison Lecture
“What came before RNA? Progress towards finding a solution to a major part of the origins of life puzzle”
The RNA World hypothesis posits that early life utilized RNA for information storage (now the job of DNA) and for catalyzing chemical reactions (now the domain of protein enzymes). While this hypothesis remains popular among many origins researchers, a persistent challenge to this hypothesis is our lack of a plausible prebiotic synthesis of RNA. Significant challenges facing the prebiotic synthesis of RNA polymers include nucleobase selection, nucleoside bond formation, and nucleotide polymerization. As possible solutions to these challenges, we are investigating the hypothesis that RNA was preceded by a polymer that would have assembled more easily on the prebiotic Earth than RNA (i.e., proto-RNA), being comprised of a different backbone and different nucleobases. In support of this hypothesis, recent advances have revealed that alternative, plausibly prebiotic nucleobases can self-assemble in water and readily form nucleosides with ribose, two properties not observed with the nucleobases currently found in RNA.