Cavemen may have had hilarious conversations like this one, using words we would understand.

Linguists generally believe that words can’t survive for more than 8,000 to 9,000 years, but a new study published in the Proceedings of the National Academy of Sciences shows that there’s a deep language ancestry evident across Eurasia, which includes words that date back as many as 15,000 years. Twenty-three “ultra-conserved” words have just been identified, as this nifty infographic shows, among them thou, bark, spit, give, and hand.

Using a statistical model to track the frequency of words in everyday speech, and to predict the existence of highly conserved words, the study identifies a remarkable “superfamily” of words. Mark Pagel and three collaborators tracked a number of cognates; for example, Father (English), padre (Italian), pere (French), pater (Latin) and pitar (Sanskrit) mean the same thing, but sound a little different. Those words are from the same Indo-European family.

In addition to Indo-European words, according to David Brown’s article in the Washington Post, the linguists examined the families of “Altaic (whose modern members include Turkish, Uzbek and Mongolian); Chukchi-Kamchatkan (languages of far northeastern Siberia); Dravidian (languages of south India); Inuit-Yupik (Arctic languages); Kartvelian (Georgian and three related languages) and Uralic (Finnish, Hungarian and a few others).”

Beginning with the Swaedish list, researchers searched for words that may have remained in use since the last Ice Age:

They looked, for example, for similar-sounding words for “fish” or “to drink” in the Altaic family of languages or in the Indo-European languages. When they found cognates, they constructed what they imagined were the cognates’ ancestral words — a task that requires knowing how sounds change between languages, such as “f” in Germanic languages becoming “p” in Romance languages.

Those made-up words are called “proto-words.” Pagel’s team compared them among language families. They made thousands of comparisons, asking such questions as: Do the proto-word for “hand” in the Inuit-Yupik language family and the proto-word for “hand” in the Indo-European language family sound similar?

In fact, they do.

The study found that “words used more than once per 1,000 in everyday speech were 7- to 10-times more likely to show deep ancestry on this tree. Our results suggest a remarkable fidelity in the transmission of some words and give theoretical justification to the search for features of language that might be preserved across wide spans of time and geography.”

The Washington Post followed up with a list of words you might use in an encounter with a caveman, including, “Hear ye, hear ye,” and “I spit on you.”

According to the study, words used at least sixteen times per day by an average speaker had the greatest chance of being cognates in three or more language families.

“I was really delighted to see ‘to give’ there,” Pagel said in an interview with the Washington Post. “Human society is characterized by a degree of cooperation and reciprocity that you simply don’t see in any other animal. Verbs tend to change fairly quickly, but that one hasn’t.” Someone call Lewis Hyde!