Language is one of the few skills that set humans apart from all other animals. That’s why scientists have long tried to determine its origins and understand its evolution. One of the avenues to do so has been through studying genetics, and now, a study seems to have found a key piece of the puzzle with the help of mice.
A team of Rockefeller University researchers, led by Yoko Tajima, published their findings in the journal Nature Communications. The study highlights a gene known as NOVA1. While it appears to be essential to all mammals, modern humans have a unique variant that came to be between 250,000 and 500,000 years ago, when the Homo sapiens split from Neanderthals and Denisovans, who lacked this variant. This made scientists wonder if NOVA1 had a particular effect and gave Homo Sapiens an evolutionary advantage.
“This gene is part of a sweeping evolutionary change in early modern humans and hints at potential ancient origins of spoken language,” says Robert B. Darnell, head of the Laboratory of Molecular Neuro-Oncology, who discovered the gene in 1993. “NOVA1 may be a bona fide human ‘language gene,’ though certainly it’s only one of many human-specific genetic changes.”
To find answers, the researchers put a human version of NOVA1 into mice. These animals communicate in chirps and squeaks in an ultrasonic range that humans can’t hear. After recording them and analyzing their interactions, the scientists realized that the human gene did change the way the rodents communicated with each other, as the genetically altered mice used more complex sounds in more intricate patterns than their counterparts. The difference was particularly striking when the modified male mice tried to attract potential female mates. “We thought, wow. We did not expect that,” Darnell admits. “It was one of those really surprising moments in science.”
The gene led to the production of 200 proteins that were not present in the control mice brain and have had an effect on the activity of other genes, including those related to the production of sounds. “Such changes may have played important roles in the acquisition of characteristics that have contributed to the emergence, expansion, and survival of Homo sapiens,” says Tajima. “Moreover, many of these vocalization-related genes were also found to be binding targets of NOVA1, further suggesting the involvement of NOVA1 in vocalization.”
The version of NOVA1 used in the experiment is overwhelmingly dominant in the human population. In a database of 650,058 genomes from around the world, it was only absent from six. While scientists don’t know anything about these individuals, they hope to find to run some language tests to determine how this may have affected them.
“We believe that understanding these issues will provide important insights into how the brain operates during vocal communications—and how its misregulation leads to certain disorders,” says Tajima. “Our discovery could have clinical relevance in many ways, ranging from developmental disorders to neurodegenerative disease.”
Sources: A humanized NOVA1 splicing factor alters mouse vocal communications; How a uniquely human genetic tweak changed the voices of mice; The Gene That Made Mice Squeak Strangely; A single protein may have helped shape the emergence of spoken language
Related Articles:
Insightful Map Shows the Language Each Country Around the World Wants To Learn the Most
Listen to How 65 Different Accents Capture the Beauty and Versatility of the English Language
Portraits Capture the Faces of America’s Endangered Languages
University Students Designed Gloves That Translate Sign Language Into Speech