A breakthrough discovery has shed light on the emergence of human language by studying mice with a unique protein variant. Researchers found that the NOVA1 gene, which is nearly ubiquitous in modern humans, plays a crucial role in the development of spoken language.
Scientists Yoko Tajima and César Vargas bred mice to carry a version of the protein found only in human brains, but not in other mammals or birds. The results showed that the mice with this variant produced more complex vocalizations than those without it. In one experiment, male mice with the humanized NOVA1 gene called out to female mice with higher-pitched and more varied squeaks.
The researchers also found that the NOVA1 protein affects not only speech but also genes involved in vocalization and speech disorders. The variant is found in nearly all modern humans, suggesting it was under strong selective pressure and may have evolved in an ancestor around 300,000 years ago.
However, other scientists argue that NOVA1 is just one piece of the puzzle, and multiple genetic changes contributed to the emergence of human language. Cognitive neuroscientist Gregory Cogan notes that the effects of NOVA1 and FOXP2 proteins on mouse vocalizations are similar, suggesting these genes may have been tweaked at least twice during human evolution.
Neurologist Robert Darnell says that the NOVA1 variant is like “extra sauce on top” that makes humans more advanced vocal learners. The discovery highlights the importance of studying genetic variations and their impact on complex behaviors like language development.
Source: https://www.science.org/content/article/eloquent-mice-point-protein-may-have-shaped-human-speech