One of the biggest scientific mysteries is how the first self replicating molecules appeared on the young Earth. The RNA world hypothesis suggests that ribonucleic acid RNA played a central role in the origin of life. New experiments by Japanese and American biochemists strengthen this idea by showing that RNA could have formed naturally as early as 200 million years after the planet’s formation.

What the RNA world is

RNA is a simpler relative of DNA. It performs three key functions in modern biology: it carries genetic information messenger RNA, forms ribosomes for protein synthesis ribosomal RNA, and directly participates in assembling proteins transfer RNA. Because of this relative simplicity and versatility, RNA is considered a strong candidate for the first self replicating molecule.

In the RNA world scenario, early single celled organisms used RNA instead of DNA to store and copy genetic information. The main challenge for this hypothesis has long been explaining how RNA could emerge from a chaotic mix of chemical reactions, since the probability of its spontaneous formation was thought to be extremely low.

Breakthrough in laboratory experiments

A research team led by Yuta Hirakawa of Tohoku University in Japan, together with the Foundation for Applied Molecular Evolution in Florida, conducted experiments that simulated conditions on the early Earth near underground hydrothermal systems.

The scientists combined the basic components of RNA: the five carbon sugar ribose, phosphates, and the four nucleobases adenine guanine cytosine and uracil. They also added borates, which are common in seawater, and basalt. The mixture was then heated and dried. Under these conditions, RNA formed.

The key surprise was the role of borates. Previously they were thought to interfere with RNA formation, but in these experiments they actually helped. Borates stabilized fragile ribose molecules and promoted phosphate formation, which are crucial steps in the discontinuous synthesis model of RNA formation.

This is the first time RNA has been produced in the laboratory without direct human control over the chemical reactions themselves, although critics note that selecting and mixing the ingredients still counts as a form of intervention.

The role of cosmic delivery

The hypothesis is further supported by data from the OSIRIS REx mission. Samples returned from the asteroid Bennu were found to contain all the components of RNA, including ribose.

Hirakawa and his colleagues suggest that a collision with a proto planet about 500 kilometers in diameter, similar to Vesta, around 4.3 billion years ago could have delivered these compounds to Earth. The timing fits well with geological evidence: this would have occurred about 200 million years after Earth formed and roughly 200 million years before the oldest known signs of life, such as carbon isotope signatures preserved in 4.1 billion year old zircons.

Similar impacts also occurred on Mars, where borates have been detected, raising the possibility that RNA friendly conditions may have existed there as well.

Why this changes the picture

If RNA could form quickly and naturally, the path toward the first living organisms becomes much shorter. RNA itself is not life, but it is the foundation of nearly all known biology.

The study was published on December 15, 2025, in the journal Proceedings of the National Academy of Sciences.

In brief

New experiments show that RNA could have formed naturally on the early Earth in the presence of borates, which help rather than hinder the process. Asteroids like Bennu likely delivered the necessary components around 4.3 billion years ago. This strengthens the RNA world hypothesis as a bridge to the first cells and helps explain why life may have emerged relatively quickly. The discovery also has implications for understanding the potential origin of life on Mars.