A human gene makes mice squeak differently — did it contribute to language?

The development of spoken language might have been influenced by a protein variant unique to humans. The NOVA1 protein, which is involved in brain development, differs between humans and animals by a single amino acid. To test the impact of such a small tweak, scientists used CRISPR gene-editing technology to replace the gene that expresses NOVA1 in mice with the version found in humans. The swap made the mice’s vocalisations more complex, which could suggest that the variant causes subtle brain changes that affect our ability to communicate.