Scientists Discover Self-Replicating RNA Molecule, Advancing Origins of Life Theory
Researchers at the MRC Laboratory of Molecular Biology have discovered QT45, a remarkably small RNA molecule capable of copying itself and its complementary strand. This breakthrough challenges previous assumptions that only large RNA could self-replicate, making the spontaneous emergence of life from simple chemical building blocks far more plausible. The discovery strongly supports the 'RNA world' hypothesis, offering critical insights into how life on Earth might have begun.
On February 13, 2026, researchers at the MRC Laboratory of Molecular Biology (LMB) announced a significant chemical breakthrough, discovering a tiny RNA molecule that could explain how life on Earth began. Published in the journal Science, the findings reveal the team identified QT45, a remarkably small ribonucleic acid (RNA) molecule that can copy itself and its complementary strand. This capacity for self-replication is a key step towards understanding the emergence of life from simple chemical building blocks, a central question in science.Historically, scientists had only found RNA strands capable of copying other RNA, but these were considered too long and complex to have emerged spontaneously and copy themselves entirely. QT45, a short RNA polymerase ribozyme, challenges this by demonstrating that small RNA molecules can achieve self-replication. Its diminutive size is crucial; it not only makes self-copying much easier but also makes its spontaneous appearance in a 'primordial soup' a far more plausible scenario. Lead author Edoardo Gianni emphasized that this discovery makes the 'self-replicating RNA' hypothesis much more likely, as QT45 managed to copy all of itself and its template, unlike previous longer RNA sequences.The LMB team achieved this by generating vast pools of random RNA sequences and selecting for RNA-copying activity through repeated rounds of laboratory evolution, leading to the emergence of QT45. Beyond its scientific significance for Earth's origins, the discovery also has implications for how likely life is to emerge spontaneously and whether similar processes could occur on other planets. The team now aims to combine the two key reactions needed for self-replication to kickstart a continuous self-replication cycle.
