The word lox was one of the clues that eventually led linguists to discover who the Proto-Indo-Europeans were, and where they lived. The fact that those distantly related Indo-European languages had almost the same pronunciation of a single word meant that the word—and the concept behind it—had most likely existed in the Proto-Indo-European language. “If they had a word for it, they must have lived in a place where there was salmon,” explains Guy. “Salmon is a fish that lives in the ocean, reproduces in fresh water and swims up to rivers to lay eggs and mate. There are only a few places on the planet where that happens.”

They were able to track down other words that the Indo-Europeans had and then roughly pinpoint their location: the Pontic Steppes, or Modern Ukraine.

The English Word That Hasn’t Changed in Sound or Meaning in 8,000 Years