By Erin Wayman
BOSTON — “Birdbrain” may not be much of an insult: Humans and songbirds share genetic changes affecting parts of the brain related to singing and speaking, new research shows. The finding may help scientists better understand how human language evolved, as well as unravel the causes of speech impairments.
Neurobiologist Erich Jarvis of Duke University Medical Center in Durham, N.C., and colleagues discovered roughly 80 genes that turn on and off in similar ways in the brains of humans and songbirds such as zebra finches and parakeets. This gene activity, which occurs in brain regions involved in the ability to imitate sounds and to speak and sing, is not present in birds that can’t learn songs or mimic sounds. Jarvis described the work February 15 at the annual meeting of the American Association for the Advancement of Science.
Songbirds are good models for language because the birds are born not knowing the songs they will sing as adults. Like human infants learning a specific language, the birds have to observe and imitate others to pick up the tunes they croon. The ancestors of humans and songbirds split some 300 million years ago, suggesting the two groups independently acquired a similar capacity for song.