Neuroscientist and Duke University Medical School neurobiology professor Erich Jarvis has gone to the birds. Jarvis studies birds, but his interest didn't start with an affinity for feathers, according to Phys.org. Jarvis was interested in how the human brain reproduces speech.
"We've known for many years that the singing behavior of birds is similar to speech in humans - not identical, but similar - and that the brain circuitry is similar, too," said Jarvis, according to Phys.org. "But we didn't know whether or not those features were the same because the genes were also the same."
Scientists now say, "yes," the genes are basically the same.
Jarvis and colleagues sequenced and compared genomes of 48 species of birds and discovered that vocal learning evolved two or three times in songbirds, parrots and hummingbirds and that the genes involved are similar to the genes responsible for humans' ability to speak, according to Phys.org.
One of the studies published in the journal Science noted that there is a consistent set of more than 50 genes that demonstrate high or low brain activity in humans and vocal-learning birds. These were not present in unvocal birds or non-human primates that don't speak. The genes form connections between the motor cortex and sound-producing muscles, according to Phys.org.
"This means that vocal learning birds and humans are more similar to each other for these genes in song and speech brain areas than other birds and primates are to them," Jarvis said, according to Phys.org.
"You can find those same genes in the genomes of all species, but they're active at much higher or lower levels in the specialized song or speech brain regions of vocal learning birds and humans," Jarvis said, according to Phys.org. "What this suggests to me is that when vocal learning evolves, there may be a limited way in which the brain circuits can evolve."
"Speech is difficult to study in human brains," he said, according to Phys.org. "Whales and elephants learn speech and songs, but they're too big to house in the lab. Now that we have a deeper understanding of how similar birdsong brain regions are to human speech regions at the genetic level, I think they'll be a better model than ever."
