For centuries, scientists have wondered what makes human speech unique. Why can we hold conversations while our closest relatives, like Neanderthals, could not? New research may have uncovered a key piece of the puzzle—a tiny genetic change that exists in modern humans but not in our extinct relatives.
New research centers on a brain protein called NOVA1, which plays a crucial role in how nerve cells process information. Researchers at The Rockefeller University have discovered that a single genetic mutation in NOVA1 may have influenced the development of spoken language, setting early humans apart from other species.
See, NOVA1 acts like a conductor in the brain, controlling how other genes are expressed in nerve cells. The human version of this gene differs from that found in Neanderthals, Denisovans, and other animals by just one tiny amino acid change. However, that slight difference appears to be the key that unlocked human speech.
To test its effects, scientists genetically engineered mice to carry the human version of NOVA1. While the mice developed normally, their vocalizations changed. Baby mice with the human gene produced different cries when separated from their mothers, and adult males altered their ultrasonic mating calls, creating unique sound patterns.
These findings suggest that NOVA1 plays a vital role in how vocal behaviors are formed and processed in the brain, offering a potential genetic explanation for why only humans developed complex speech. Of course, it isn’t the full puzzle to why human speech is so unique, but it does provide a foundation to build off.
When researchers further examined the DNA of Neanderthals and Denisovans, they found that these ancient humans had the same version of NOVA1 as other animals, which means they lacked the mutation found in modern humans.
These findings suggest that somewhere in Africa, early modern humans developed this mutation, which then spread rapidly across populations, enabling the foundation of human speech. The fact that it became nearly universal hints that it provided enough of an evolutionary advantage to become a staple of the human genome.