As human beings, language has always been a unique quality of ours that allows us to express the complexity of our thoughts regarding the world around us in an astonishing number of ways. Language has been so essential to our development, and recent research has shown it is human instinct to recognize sound patterns within language. But if language is our key to communication, why is it so diversified around the world? How has language evolved, and how can we map the origins of where our language came from, and its commonalities with other languages?

Researchers in the U.S. and UK are seeking to do just that, tracing changes to words pronunciations’ back thousands of years further than anyone has before. In a new study published in the journal Current Biology, Professor Tanmoy Bhattacharya of the Santa Fe Institute and Professor Mark Pagel of the University of Reading have developed a new model that has been able to track languages back to their earliest common ancestors. Pagel claims, “Our new method is another exciting step to understanding how languages and genes evolve. It will allow us to go back in time further than before, making it possible to reconstruct ancient proto-languages, words that might have been spoken many thousands of years ago.”

Their model consists primarily of detecting “concerted sound changes,” a linguistic pattern where a distinct sound changes to another distinct sound in many words simultaneously. “Computers so far have mainly used the presence or absence of words with common origin in various languages to stitch together trees that describe the descent of the various languages from a common ancestor,” Professor Bhattacharya said. “This has left out the vastly richer data residing in sounds, primarily because sound changes in different words are not independent, as most mutations in genetics are.”

This concerted sound change can be seen through the deviation in pronunciation of words common to both Latin and English. Both languages came from the common ancestor, proto-Indoeuropean, but in English, words like foot and father took on the f sound, while their Latin equivalents ped and pater kept their p sound. This transition from f to p sounds can be seen in many English words.

The model was specifically applied to the family of 35 languages known as Turkic, spoken by many people in Southeastern Europe, the Mediterranean, Siberia, and Western China. Their computer program analyzed the possibility that over 70 regular sound changes had occurred during the 2000-year history of Turkic languages. What they found was similar to the sound changes between English and Latin. For example, the word pas in Khakassian (head in English) deviated from the initial b sound occurring in the Turkish, Uzbek, and 16 other Turkic languages’ word baš. This deviation can also be seen in the Khakassian pel (meaning louse), which is bil- or bel- in the aforementioned languages.

The researchers were able to develop mathematics to evaluate their hypotheses about concerted sound changes, and this data showed that their current model was able to provide much more conclusive dated trees for the Turkic language family than ever before. Bhattacharya and Pagel’s method proves to be revolutionary in our understanding of human language, allowing us to not only detect languages’ evolution but how our own played a part in the way we communicate.

Source: Bhattacharya T, Meade A, Pagel M, et al. Detecting Regular Sound Changes in Linguistics as Events of Concerted Evolution. Current Biology. 2015.