Life probably began with a molecule, or set of molecules, that could make copies of themselves. Now we have taken a big step towards creating such molecules ourselves.

Over the last four decades, biologists have made lots of progress towards creating self-replicating molecules in the lab. However, their efforts have been thwarted by an apparent paradox.

Now Philipp Holliger and his colleagues at the MRC Laboratory of Molecular Biology in Cambridge, UK say they have found the answer.

There are many reasons to think that…