The possibility has been raised that the complex language ability unique to humans emerged due to a specific genetic mutation. Although extinct primitive humans had similar anatomical structures for speaking and hearing as modern humans, they did not possess the same genetic mutation.
Researchers at Rockefeller University in the U.S. noted on the 18th that they discovered important genetic mutations related to human language ability, as reported in the international journal "Nature Communications."
Humans are the only animals capable of using complex language. Distant relatives of humans, such as Neanderthals, also had anatomical features that allowed them to speak and hear, but the sophisticated language ability to convey information by combining consonants and vowels is possessed only by modern humans. The expansion of critical brain regions for creating and understanding language is also seen exclusively in modern humans.
Scientists have traced the origins of language ability at the genetic level. In the past, the gene "FOXP2" was known to be related to language ability. Individuals with mutations in this gene have shown language disorders due to an inability to properly control the movements of their lips and mouths. However, Neanderthals also possessed the same FOXP2 gene as humans but did not use complex language like modern humans. This means that human language ability cannot be explained solely by FOXP2.
The research team focused on the gene that produces the "NOVA1" protein in the brain. NOVA1 plays a crucial role in the development of the brain and the control of body movements. The NOVA1 of humans differs from that of other animals. The protein is formed by linked amino acids. The human NOVA1 gene has a mutation that replaces isoleucine with valine at position 197 of the amino acids.
The research team implemented the NOVA1 gene mutation, found only in humans, in laboratory mice. As a result, the way the mice produced sounds changed. Baby mice use four different types of sounds to call their mothers. However, baby mice with the unique NOVA1 mutation produced sounds different from their usual ones. In other words, it was like changing some letters in the words they usually used. Aside from this, there were no significant changes in neural development or motor control. This result suggests that the NOVA1 mutation may have played a significant role in the evolution of human language.
To understand the impact of the NOVA1 mutation on human evolution, researchers compared the genes of ancient and modern humans. Most modern humans have the NOVA1 mutation, but those species that entered Eurasia before modern humans and subsequently went extinct, such as Neanderthals and Denisovans, lacked this mutation.
This indicates that the ancestors of modern humans acquired the NOVA1 mutation while evolving in Africa, and subsequently, as they spread globally, their language abilities developed. Professor Robert Dunell of Rockefeller University, who led the research, explained, "The NOVA1 mutation is one of the significant evolutionary changes in early modern humans," adding that it could be a critical clue in unraveling the origins of human language.
The research team plans to study how the NOVA1 mutation relates to language disorders and developmental disabilities in the future. Yoko Tajima, the first author of the study and a postdoctoral researcher at Rockefeller University, stated, "Understanding how NOVA1 functions will help us learn how the brain operates when humans speak and provide important clues in identifying specific disabilities caused by neural control issues."
References
Nature Communications (2025), DOI: https://doi.org/10.1038/s41467-025-56579-2