A unique variant protein may hold the key to the origin of human speech
Kyiv • UNN
Researchers have discovered a unique variant of the NOVA1 (I197V) protein that only modern humans have. This genetic feature was absent in Neanderthals and appeared after the evolutionary separation of humans.
The study, published in the journal Nature Communications, describes a unique variant in a neural RNA-binding protein in the human central nervous system. This amino acid change (called I197V) is likely to hold the key to understanding how humans evolved the ability to speak in complex ways.
Transmits UNN with reference to Nature and DW.
Details
Our ancestors, as well as our closest relatives such as Neanderthals, likely had anatomical features in their throats and ears that enabled them to speak and hear spoken language. Science knows that they and we share the same gene variant that is associated with the ability to speak. However, it was not yet known why humans have their own unique variation in the gene.
In the context of the peculiarities of the human speech tract and the complex neural networks that make our speech abilities possible, the RNA-binding protein NOVA1 should be highlighted. It is key to brain development and neuromuscular control and is found in many parts of the biosphere, from mammals to birds. In humans, the I197V variant is present in the protein chain.
In a series of studies, a team of scientists from The Rockefeller University used CRISPR gene editing to replace the NOVA1 protein, which is common in mice, with the human variant I197V.
The scientists found that it was the human I197V that contributed to the emergence of spoken language.
This gene is part of a radical evolutionary shift in early modern humans and points to a possible ancient origin of spoken language.
The researcher even concedes that NOVA1 could be the real human ‘language gene’, but admits that it is more likely to be ‘one of many genetic changes specific to humans’.
Deep into the ages
Studying the genomes of archaic human relatives, the Neanderthals (a subspecies of Late Pleistocene man) of Europe and the Denisovans of Central Asia (a species of extinct humans known from extremely fragmentary material), scientists have found that the ancient species of humans had the same NOVA1 variant as other animals. However, it is in modern humans that the unique I197V version dominates.
An interesting fact: analyses of over 650,000 genomes of modern humans documented the presence of I197V in all but six individuals.
This is evidence of a unique human variation. It manifested as far back as Africa, after we separated evolutionarily from our ancient relatives. It is also a clue that this NOVA1 change may be an unexpected human-specific gene associated specifically with language.
Recall
Research has shown that the brain retains memories from the period of childhood amnesia to adulthood, although they are not consciously remembered. The age of the first memories and their detail depend on the cultural environment and upbringing.
