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taylorvich [soylentnews.org] writes:

https://phys.org/news/2025-02-protein-emergence-spoken-language.html [phys.org]

The origins of human language remain mysterious. Are we the only animals truly capable of complex speech? Are Homo sapiens the only hominids who could give detailed directions to a far-off freshwater source or describe the nuanced purples and reds of a dramatic sunset?

Close relatives of ours such as the Neanderthals likely had anatomical features in the throat and ears that could have enabled the speaking and hearing of spoken language, and they share with us a variant of a gene linked to the ability to speak. And yet it is only in modern humans that we find expanded brain regions that are critical for language production and comprehension.

Now researchers from The Rockefeller University have unearthed intriguing genetic evidence: a protein variant found only in humans that may have helped shape the emergence of spoken language.

In a study published in Nature Communications, researchers in the lab of Rockefeller researcher Robert B. Darnell discovered that when they put this exclusively human variant of NOVA1—an RNA-binding protein in the brain known to be crucial to neural development—into mice, it altered their vocalizations as they called to each other.

The study also confirmed that the variant is not found in either Neanderthals or Denisovans, archaic humans that our ancestors interbred with, as is evidenced by their genetic traces that remain in many human genomes today.

"This gene is part of a sweeping evolutionary change in early modern humans and hints at potential ancient origins of spoken language," says 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."

Anatomical adaptations of the vocal tract and intricate neural networks enable our language capabilities. But the genetics behind them isn't well understood.

One theorized genetic language driver is FOXP2, which codes for a transcription factor involved in early brain development. People with mutations in this gene exhibit severe speech defects, including the inability to coordinate lip and mouth movements with sound.

Humans have two amino acid substitutions in FOXP2 that aren't found in other primates or mammals—but Neanderthals had them too, suggesting that the variant arose in an ancestor of both human lineages. But some findings on FOXP2 have been disputed, and its role in human language development remains unclear.

Now NOVA1 has arisen as a candidate. The gene produces a neuron-specific RNA binding protein key to brain development and neuromuscular control that was first cloned and characterized by Darnell in 1993. It's found in virtually identical form across a wide swath of the biosphere, from mammals to birds—but not in humans.

Instead, humans have a unique form characterized by a single change of an amino acid, from isoleucine to valine, at position 197 (I197V) in the protein chain.

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