The End of the RNA World Is Near, Biochemists ArgueFor decades, an origin-of-life story starring RNA has prevailed. New research may be shaking that theory’s hold on our understanding of life’s beginnings.A popular theory holds that life emerged from a rich chemical soup in which RNA was the original self-replicator. But a combination of peptides and RNA might have been more effective.Four billion years ago, the first molecular precursors to life emerged, swirling about in Earth’s primordial soup of chemicals. Although the identity of these molecules remains a subject of fractious debate, scientists agree that the molecules would have had to perform two major functions: storing information and catalyzing chemical reactions. The modern cell assigns these responsibilities to its DNA and its proteins, respectively — but according to the narrative that dominates origin-of-life research and biology-textbook descriptions today, RNA was the first to play that role, paving the way for this hypothesis, proposed in the 1960s and dubbed the “RNA world” two decades later, is usually viewed as the most likely explanation for how life got its start. Alternative “worlds” abound, but they’re often seen as fallback theories, flights of fancy or whimsical thought experiments.