Languages are like species. They evolve in mostly predictable ways, splitting into new species or dying out over time. Now, a group of linguists and computer scientists in the US and Canada have created a piece of software that can analyze enormous groups of languages to reconstruct what the earliest human languages might have sounded like.

It sounds like a subplot from Neal Stephenson’s novel Snow Crash, but it’s quite real. By using this program and others like it, linguists may one day know how people sounded when they talked 20,000 years ago, long before there was writing.