How Genetics Guide the Evolution of Language
More than 7,000 languages have evolved across the globe as different cultures have migrated, interacted with each other and isolated themselves. New research, though, suggests another factor has played a major role in the way these languages changed: genetics.
A study led by Kevin Tang, UF assistant professor of computational language science and the director of the Speech, Lexicon and Modeling (SLaM) Lab in the Department of Linguistics, highlights how gene variations can, over time, guide the course of an entire language.
While linguists have long studied how languages evolve, until recently genetics have been largely left out of the picture. But in the era of big data, advances in genome sequencing, as well as the creation of massive typological databases, have allowed new insights into the relationship between our speech and our genetic code.
“We’re now looking at the actual hardware that allow us to be human,” Tang said. “This adds a missing piece of the puzzle. Big data is enabling us to detect these subtle signals.”
Tang and collaborators from Yale University and Brock University looked at a specific gene associated with how people process sounds. While a variation in this gene — known as an allele — may have a subtle effect on a single person’s speech, over time the allele’s prevalence in a group of people can have a long-term impact on how the whole culture communicates, causing them to favor certain sounds over others.
The researchers found that high prevalence of RU1-1 alleles in a culture was associated with its language having more “stop consonants,” sounds that involve the complete stop of airflow. Meanwhile, those cultures in which these alleles were less common had more “nasal consonants,” or sounds made while airflow continues through the nose. Their findings suggest that these patterns are driven by stop consonants’ vulnerability to the loss of precision in the timing of neuron spikes compared to more robust nasal consonants.
Looking ahead, the researchers plan to examine more genetic variations that may have had an impact on language.