The search for the dawn of life Premium

How would ribonucleotides, the building blocks, have formed on the early Earth, and then combined into RNA?

How did life begin? How did chemical reactions on the early Earth create complex, self-replicating structures that developed into living things as we know them?

According to one school of thought, before the current era of DNA-based life, there was a kind of molecule called RNA (or ribonucleic acid). RNA – which is still a crucial component of life today – can replicate itself and catalyse other chemical reactions.

But RNA molecules themselves are made from smaller components called ribonucleotides. How would these building blocks have formed on the early Earth, and then combined into RNA?

Chemists like me are trying to recreate the chain of reactions required to form RNA at the dawn of life, but it’s a challenging task. We know whatever chemical reaction created ribonucleotides must have been able to happen in the messy, complicated environment found on our planet billions of years ago.

I have been studying whether “autocatalytic” reactions may have played a part. These are reactions that produce chemicals that encourage the same reaction to happen again, which means they can sustain themselves in a wide range of circumstances.

In our latest work, my colleagues and I have integrated autocatalysis into a well-known chemical pathway for producing the ribonucleotide building blocks, which could have plausibly happened with the simple molecules and complex conditions found on the early Earth.

Autocatalytic reactions play crucial roles in biology, from regulating our heartbeats to forming patterns on seashells. In fact, the replication of life itself, where one cell takes in nutrients and energy from the environment to produce two cells, is a particularly complicated example of autocatalysis.