ADRIAN FLORIDO, HOST:
People like to talk. We're unique in the animal kingdom in terms of how much we communicate and the kinds of information we discuss. Scientists are trying to understand how this special trait evolved at the genetic level. NPR's Nell Greenfieldboyce reports on what happened recently when researchers gave mice the human version of one particular gene.
NELL GREENFIELDBOYCE, BYLINE: If someone asked you what kind of sound a mouse makes, you'd probably go, squeak. But mice also make some sounds in the ultrasonic range that humans can't hear. If you process those sounds so that we can hear them...
(SOUNDBITE OF HIGH-PITCHED MOUSE SQUEAKING)
GREENFIELDBOYCE: ...It's a lot like bird song. Erich Jarvis is a researcher at Rockefeller University in New York. He says mouse pups chirp when they're taken away from their mothers, and as adults, male mice string long sequences of these chirps together.
ERICH JARVIS: And they'll sing them to the females as a courtship behavior.
GREENFIELDBOYCE: Recently, Jarvis teamed up with some other researchers at Rockefeller University to study one particular gene. This gene is found in living creatures, from mammals to birds, but there's one particular variant that's found only in people. When they put that uniquely human variant into mice, it subtly changed the vocalizations made by babies and adult males.
(SOUNDBITE OF HIGH-PITCHED MOUSE SQUEAKING)
GREENFIELDBOYCE: Jarvis says their analysis showed that the mouse songs became more complex.
JARVIS: So the fact that we had a change in the vocal behavior was really exciting.
GREENFIELDBOYCE: He says this gene could be related to speech and language, although it's clearly not the only language gene.
JARVIS: I don't think that one gene is going to be responsible - poof - and you got spoken language, right?
GREENFIELDBOYCE: Still, this gene is especially intriguing because it's active in the brain and this variant seems to be only found in modern humans. Robert Darnell is a neuroscientist, also at Rockefeller University. He says they've looked at genetic information in databases and found that this variant is present in almost every single person from around the world, but it's not found in chimps or extinct human species like Neanderthals.
ROBERT DARNELL: This is a human language gene that changed and switched early in the development of Homo sapiens.
GREENFIELDBOYCE: A report on the findings appears in the journal Nature Communications, and it's got the attention of other scientists interested in the genetic underpinnings of language. Cedric Boeckx is with the Catalan Institute for Advanced Studies and Research and the University of Barcelona. He says it's a real advance.
CEDRIC BOECKX: It's one gene among many still to be uncovered in a complex network that influence this and make possible this capacity we have.
GREENFIELDBOYCE: He cautions, though, that it's hard to make a jump from mouse vocalizations to human speech. A mouse is not your typical vocal learner.
BOECKX: It produces vocalizations, but they are mostly innately constrained. So it's not like us.
GREENFIELDBOYCE: He says humans are special in how we communicate, and knowing the list of genes involved in language could tell us something about how humans came to be who we are.
Nell Greenfieldboyce, NPR News.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.
