A collaboration between linguists and SFI scientists is using a novel statistical technique to trace the evolutionary origins of a native North American language.

In February, a small group gathered at SFI to experiment with using phonetic shifts in the Athapaskan languages to reconstruct
the language group’s evolution. Athapaskan languages are spoken by the Dene people, whose native territories cover a large swath of North America from Alaska to the American Southwest. Despite uncanny linguistic and cultural similarities among Dene tribes, details of their ancestry and historical migration patterns are a subject of scholarly contention.

SFI Professor Tanmoy Bhattacharya and External Professor Daniel Hruschka (Arizona State University) arranged the meeting to explore whether a statistical technique their research team has developed could shed light on the linguistic and cultural evolution of the Dene tribes.

Sally Rice, a cognitive linguist from the University of Alberta, presented background on Dene languages and culture, and explained some outstanding mysteries in Dene scholarship. She has developed a comparative lexicon for Athapaskan languages and wanted to see if linguistic classification of Athapaskan provided evidence for her hypothesis that the Alaskan Dene people are ancestors of the Plains Apache people.

To quantify the relationship between two Athapaskan dialects, Bhattacharya and Hruschka’s method measures the evolutionary distance between the two languages by statistically analyzing the sound components of words. If, for example, a "t" sound in one language systematically evolves to a "d" sound, the word tear in one language would sound as dear in its descendant.

In January, the SFI scientists published a detailed classification of the Turkic language group by this method, the results of which agree with widely-accepted history of Turkic language evolution (see article on page 1). They hope their method will prove similarly effective in classifying Athapaskan, whose evolution is less certain.

“Genetically, southern Dene tribes borrow heavily from other cultures,” Bhattacharya says. “But linguistically, they are completely northern. There’s a lot of dispute over how their migration happened, and analyzing the sound changes should shed some light on that history. We have never tried it, so we don’t yet know. That’s one of the exciting things about science.”