Scientists have discovered the gene for human speech and transferred it to mice 🗣️

A genetic mutation unique to humans could explain the emergence of speech. Researchers have found that inserting this variant into mice alters their vocalizations, opening a new avenue for understanding the origins of language.

Language is a defining characteristic of the human species, but its origins remain poorly understood. A recent study, published in Nature Communications, explores the role of a gene called NOVA1. This gene, present in many species, has a unique variant in humans that appeared approximately 250,000 to 500,000 years ago. This tiny but crucial mutation may have played a key role in the development of speech.

NOVA1: a gene with multiple implications

NOVA1 is a gene essential for brain development. It contributes to the formation and functioning of neurons. It codes for a protein that regulates alternative splicing, a mechanism that allows a single gene to produce multiple proteins. This process is crucial for the diversity of cellular functions, particularly in the nervous system.

In humans, a single amino acid change distinguishes the NOVA1 variant from that of other species, including Neanderthals and Denisovans. This mutation, though minuscule, could have major implications for the evolution of our species.

To study the effect of this human variant, researchers used CRISPR technology to replace the NOVA1 version in mice with the human version. The genetically modified mice showed significant changes in their vocalizations. The pups emitted higher-pitched and more varied cries when calling for their mother, while adult males produced more complex sound sequences during courtship. These changes suggest that the human variant of NOVA1 influences neural circuits involved in communication.

A piece of the puzzle in the evolution of language

The discovery of NOVA1's potential role in the emergence of speech is a significant breakthrough, but it is important to remember that human language is the result of a long evolutionary process. While NOVA1 sheds new light on the genetic mechanisms at play, it is only one piece of a much larger puzzle. The emergence of speech is likely the result of a combination of genetic, neurological, anatomical, and environmental factors that have influenced each other over time.

Among the other pieces of this puzzle, the FOXP2 gene, often referred to as the "language gene," holds a prominent place. Identified over twenty years ago, FOXP2 is essential for the development of brain areas involved in speech and language. Mutations in this gene can lead to severe speech disorders. However, unlike NOVA1, FOXP2 is not unique to humans: it is present in other species, including our Neanderthal cousins. This suggests that FOXP2 plays a more general role in communication and that its human version has been co-opted to serve the specific needs of articulated language.

Beyond genes, the evolution of our vocal anatomy has also been crucial. For example, the descent of the larynx created a larger resonance space, enabling the production of a wider range of sounds. The shape and mobility of our tongue, as well as the development of our nervous system, have also contributed to our ability to articulate sounds and organize them into words and sentences. Finally, let's not forget the influence of the social and cultural environment: language is above all a tool for communication, transmitted and enriched through our interactions with others.

Thus, while the discovery of NOVA1 represents a promising advance, it should not overshadow the uniqueness of human language. Many questions remain unanswered and will require further research. The study of genes, anatomy, brain development, and social interactions, combined with interdisciplinary approaches such as paleontology and archaeology, will allow us to gradually reconstruct the history of the emergence of speech, this unique ability that defines us as human beings.