Why only humans can speak the way they do and not other animals

If there’s one ability that makes humans stronger and smarter than their ancient relatives and current interspecies-it’s their power to speak. The unique art of communication separates them from any other organism and makes them superior in the realms of development and evolution. It forms the connecting web of human society, propelling it towards the future. But where did it all begin? Since when did those who communicated through engravings and signs evolve to express through words and sounds? If you’ve ever pondered upon this question, a recent research conducted by researchers at The Rockefeller University, New York has found the answers for you.
Close relatives of the modern humans such as the Neanderthals and Denisovans possessed the anatomical features of the throat and ears that could have enabled them to speak and hear. Yet, the only humans that are able to exercise these abilities to the fullest extent are the Homo sapiens who have the evolved brain regions that are critical for language comprehension and production.
The reason for this intriguing development is a protein variant found exclusively in humans. NOVA1- an RNA-binding protein in the brain that regulates neural development and motor control. A genetic mutation in NOVA1 may have impacted the development of spoken language, setting the stage for the progress of future humans. A single amino acid change in the protein altered the way early humans processed vocalization-associated signals, helping them process the messages and act upon them.
The experiments towards substantiating this discovery were conducted in a study published in the journal, Nature Communications. Researchers in the lab of Rockefeller researcher Robert B. Darnell discovered that when they put the human variant of NOVA1 in mice, it altered their ways of calling to each other. In baby mice the human gene produced varied cries when separated from their mothers, whereas in adult males it altered their ultrasonic mating calls, creating unique sound patterns.
To further corroborate this intriguing finding, the researchers examined the DNA of Neanderthals and Denisovans. They found out that these ancient beings had the same version of NOVA1 as the animals, meaning they lacked the mutation found in modern humans. The findings from the research suggest that advanced humans developed these mutations somewhere in Africa from where it spread rapidly across populations.
“This gene is part of a sweeping evolutionary change in early modern humans and hints at potential ancient origins of spoken language,” said Darnell, head of the Laboratory of Molecular Neuro-Oncology. “NOVA1 may be a bona fide human ‘language gene,’ though certainly it’s only one of many human-specific genetic changes,” he added. The findings indicate that the presence of NOVA1 is pivotal in the way vocal behaviours are formed and processed in the brain, solving one of the many mysteries on why humans are the only beings with a developed complex speech system.
It is surprising to see how the creation of a minute mutation in a protein led to the development of the ability to speak, one of the most essential capabilities of the social animals, humans. While the discovery does not solve the complete puzzle on why humans are the only ones to possess this unique ability, it does present a foundation on which further studies can be based and new findings can be made.