A team of scientists at Rockefeller University has identified a human-specific protein variant, I197V, that may have played a key role in the development of spoken language. Unlike modern humans, Neanderthals and Denisovans did not carry this variant. The study, published in Nature Communications, reveals how this unique variant of the NOVA1 protein—a critical player in brain development—could have influenced vocal communication.
Using CRISPR gene-editing technology, researchers introduced the human I197V variant into mice. While the variant didn’t affect RNA binding or motor control, it did alter the mice’s vocalizations, suggesting a potential link to vocal communication. The team compared human genomes with those of Neanderthals and Denisovans, confirming that the I197V variant was absent in these ancient relatives. Remarkably, out of 650,058 modern human genomes analyzed, only six individuals lacked the variant, indicating its near-universal presence in humans today.
According to Robert B. Darnell, head of the Laboratory of Molecular Neuro-Oncology at Rockefeller University, this finding highlights a significant evolutionary change in early modern humans. "NOVA1 may be one of the true 'language genes,' though it’s likely just one piece of a larger genetic puzzle," he explained. The researchers believe the I197V variant emerged in an ancestral human population in Africa, potentially providing advantages in vocal communication, and later spread worldwide as humans migrated.
Future research in Darnell’s lab will explore how NOVA1 influences language function, with a focus on developmental disorders like non-verbal autism. This discovery opens new doors to understanding the genetic roots of human language and its evolution.