Scientists uncover how ancient RNA strands stabilized to spark life on Earth

Scientists in Munich have uncovered a process that could explain how the first stable RNA molecules formed billions of years ago. The discovery sheds light on a key step in the origin of life, showing how fragile RNA strands might have survived in Earth's early watery environments.

The findings come from researchers at the ORIGINS Cluster of Excellence, who simulated ancient conditions to demonstrate how RNA double strands could have become stable enough to persist in primordial pools.

RNA is thought to be one of the first complex molecules to emerge, capable of both storing genetic information and driving chemical reactions. Yet functional RNA is highly unstable in water, breaking down rapidly—a major hurdle for its role in early life. The Munich team focused on how RNA strands might have paired up to form more durable structures.

In their experiments, the scientists recreated wet-dry cycles on volcanic glass, a surface likely present on early Earth. By repeatedly drying and rehydrating RNA solutions at controlled temperatures (around 60°C), they observed that short RNA strands combined into stable double strands of three to five base pairs. These duplexes lasted for hours, far longer than single strands would survive alone.

The researchers also found that double-stranded RNA folds into shapes that enhance its catalytic activity. This folding not only extends the molecule's lifespan but also reduces the chance of unwanted fusion with other protocells. Such stability would have been crucial in the chaotic conditions of the primordial soup.

To achieve these results, the team synthesised volcanic glass analogues, applied RNA solutions, and analysed the resulting structures using spectroscopy and sequencing. Their methods closely mimicked the natural processes that may have occurred in tidal pools or volcanic hot springs billions of years ago.

The study provides a plausible mechanism for how RNA could have stabilised long enough to kickstart life's chemical processes. Beyond explaining early biology, the findings may influence modern medical research, particularly in RNA-based vaccines and therapies.

Job Boekhoven, Professor of Supramolecular Chemistry at TUM, plans to expand this work, exploring further how the first RNA molecules formed and endured in Earth's ancient environments.