Stanford linguist Merritt Ruhlen, a long-time Santa Fe Institute collaborator who co-founded the Evolution of Human Languages project, passed away on January 29, 2021. 

Ruhlen was well known for his work tracing lexical similarities across all the major language families of the world — so-called "global etymologies." Drawing on these similarities, he made the case that these language families can be traced back to a single "mother tongue" — a claim that built on the legacy of Ruhlen’s mentor, Joseph Greenberg, and other comparative linguists before him.

“Merritt observed that you had a very similar phonetic shape for a word that, in one language, could mean ‘finger,’ in another, ‘point,’ and in a third language, ‘one out of many,’” explains SFI External Professor George Starostin, who co-directs the ongoing EHL project. “He observed that words with this kind of phonetic shape are found all over the globe in one of these meanings, and it can’t be just a coincidence.”

In 2001, Ruhlen worked closely with SFI co-founder Murray Gell-Mann and renowned linguist Sergei Starostin (George Starostin’s father) to co-found EHL, hosting its foundational meetings at SFI. The project's primary purpose is to trace the historical relationships between the world’s ~6,000 spoken languages, and to "organiz[e] them into a genealogical tree similar to the accepted classification of biological species,” according to the project website. In the early years of the project, Ruhlen helped build a database that allowed users to look up almost any language in the world to find its defining sounds and syntactic structures. Starostin says that, to this day, the database of linguistic typology is “still a good resource, and still pretty universal.” 

In 2011, Ruhlen and Gell-Mann published a major paper in the Proceedings of the National Academy of Sciences which argued that the ancient proto-language, from which most modern languages descend, followed a subject-object-verb sentence structure, as in “I - the bear - killed.” Many mainstream linguists were skeptical of their conclusion that language evolution followed a distinct path, which was based on a tentative genealogical tree for roughly 2,000 past and present languages.

A comprehensive list of Ruhlen’s books and his scholarly legacy can be found in his full obituary, provided by his widow Anca Ruhlen. It concludes:

We have yet to see how Merritt Ruhlen’s legacy plays out. But his career reminds us of what Dell Hymes wrote about Morris Swadesh, of an earlier generation: “Working at frontiers of knowledge, he could not always be sure of details, and sometimes went too far and fast for many of his colleagues to follow. He died before all could be woven together. Yet his explorations and the new dimensions he discovered have permanently extended our knowledge and conception of the contribution of linguistics to the understanding of the human past.”