A recent study has shed light on what makes human speech unique by identifying a tiny genetic change that distinguishes modern humans from their extinct relatives, such as Neanderthals and Denisovans. Researchers at The Rockefeller University have found that a mutation in the NOVA1 brain protein plays a crucial role in the development of spoken language.
NOVA1 acts like a conductor in the brain, controlling how other genes are expressed in nerve cells. While humans have a unique version of this gene with just one amino acid change, Neanderthals and Denisovans lacked this mutation. To test its effects, scientists genetically engineered mice to carry the human version of NOVA1.
The study found that 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 is essential for forming and processing vocal behaviors in the brain, providing a potential genetic explanation for why only humans developed complex speech.
The discovery was made by examining the DNA of Neanderthals and Denisovans, which revealed they had the same version of NOVA1 as other animals. This suggests that early modern humans developed this mutation in Africa, which then spread rapidly across populations, enabling the foundation of human speech. The fact that it became nearly universal hints that it provided an evolutionary advantage, making it a staple of the human genome.
Source: https://bgr.com/science/we-may-finally-have-an-explanation-for-why-only-humans-can-speak