Human-Specific Gene Variant Linked to Speech Evolution

A newly identified gene variant, found exclusively in modern humans, appears to influence complex speech capabilities, distinguishing us from Neanderthals and Denisovans. Researchers at Rockefeller University discovered that a protein variant, present only in Homo sapiens, alters vocalization. When introduced into mice, this version of the NOVA1 gene changed the ultrasonic calls the animals produced, suggesting a role in the evolution of human speech. The human-specific variant contains a single amino acid substitution referred to as I197V. Scientists used CRISPR editing to replace the standard NOVA1 gene in mice with the human-specific variant. Study leader Robert B. Darnell noted that the engineered mice produced distinct vocal patterns when tested how adult male mice "spoke" to female mice during mating attempts. The researchers compared modern human NOVA1 to the genomes of Neanderthals and Denisovans, human relatives who lived tens of thousands of years ago. Both archaic lineages possessed the older NOVA1 form seen in other species - lacking the I197V substitution. A check of over 650,000 modern human genomes revealed that nearly everyone carries the I197V version of NOVA1.