Humans’ and songbirds’ brains are affected in similar ways by genes relating to speaking and singing. New research by Duke University Medical Center neurobiologist Erich Jarvis and colleagues suggests that gene activity in about 80 genes is comparable between humans and songbirds. Birds that cannot produce mimicked sound do not have this brain activity.
Songbirds learn their “language” much as infant humans do. They are not born knowing how to sing their species’ song; they must learn it by observing and imitating adult birds. Because the common ancestor for birds and humans existed some 300 million years ago, Jarvis believes that the two groups experienced convergent evolution, and their brain structure similarities are analogous.
Jarvis and colleagues examined tissue from the brains of humans, in addition to tissue from the brains of song-producing and non-song-producing birds. Genes in analogous regions Area X in birds and the anterior striatum at the base of the forebrain in humans share a similar function, helping enable the organism to imitate sounds. Gene similarities were also found in the robust nucleus of the acropallium in birds, and the laryngeal motor cortex in humans. These areas are responsible for speech and song production.
Scientists hope that further research in this area will help us understand how human language involved, and how speech orders arise.
Written by Alice Metz.