The Iliad—Homer’s story of the Trojan War, and the battle between Agamemon and Achilles—is one of the oldest examples we have of Western literature. But when was it actually written? To answer that question, you might turn to a historian or a literary scholar. But geneticists wanted a crack at it, too.

It turns out that tracing the evolution and history of a book is a lot like tracing the evolution and history of a people or language. Geneticists from the journal BioEssays just applied their methods to the Iliad, writing:

Here we apply evolutionary-linguistic phylogenetic statistical methods to differences in Homeric, Modern Greek and ancient Hittite vocabulary items to estimate a date of approximately 710–760 BCE for these great works.

Basically, the geneticists traced the words present in The Iliad the way they might trace genes – using a database of concepts and words that appear in every language as the gene bank. That word database is called the Swadesh word list, and it contains about 200 words that exist in everyone language and culture, like water and dog. They found 173 words that exist in both the Iliad and the Swadesh list and then watched them evolve over time. Inside Science explains:

For example, they looked at cognates, words derived from ancestral words. There is “water” in English, “wasser” in German, “vatten” in Swedish, all cognates emanating from “wator” in proto-German. However, the Old English “hund” later became “hound” but eventually was replaced by “dog,” not a cognate.

The author of the study knows you might be surprised at this technique, but he says you shouldn’t be. Inside Science spoke with him:

“Languages behave just extraordinarily like genes,” Pagel said. “It is directly analogous. We tried to document the regularities in linguistic evolution and study Homer’s vocabulary as a way of seeing if language evolves the way we think it does. If so, then we should be able to find a date for Homer.”

And the date that Pagel came up with is pretty close to what historians and linguists estimate. They put the date of the Iliad at around 762 B.C., plus or minus fifty years or so. Pagel’s estimate fits that guess as well. Science might not be able to help you read and appreciate the epic work, but they can at least tell you how old it might be.

More from Smithsonian.com:

Speeding through the Great Books on the road to higher learning

Preserving the World’s Most Important Artifacts