Song-Learning Birds Shed Light on Our Ability to Speak

From Scientific American:

Bird A new study may have been for (and about) the birds, but it also hints at how humans may have developed the ability to speak, potentially paving the way to one day to identifying the causes of speech deficiencies. Duke University scientists report in PLoS ONE this week that they attempted to pinpoint regions of the brain responsible for vocal skills by studying three types of birds (parrots, hummingbirds, and songbirds) capable of picking up new songs and utterances as well as birds (zebra finches and ringed turtle doves) that lack the ability. Their findings: vocal pathways are always nestled in the same areas of the brain that control body movement.

“The vocal learning system is embedded within [an] ancient pathway'” designed to handle motor function that, in birds, controls their wings and legs, says study co-author Erich Jarvis, an associate professor of neurobiology at Duke University. So how did some birds develop an ability to learn new sounds? Jarvis speculates that the ability evolved from motor function or, more specifically, that the original “wiring” in the pathway linked to limbs may have duplicated and connected to vocal organs in these birds. He believes that human language pathways may have developed in a similar fashion, given that our ability to speak is based on controlling movements in the larynx (voice box).

More here.