Dr. Erich Jarvis

Some have argued, and I would agree based upon what we've seen,

is that there is an evolutionary relationship between the brain pathways that control speech production and gesturing.

And the brain regions I mentioned are directly adjacent to each other.

And why is that?

I think that the brain pathways that control speech evolved out of the brain pathways that control body movement.

And that when you talk about Italian, French, English, and so forth, each one of those languages come with a learned set of gestures that you can communicate with.

Now, how is that related to other animals?

Well, Coco, a gorilla who is raised with humans for 39 years or more, learned how to do gesture.

communication, learn how to sign language, so to speak, right?

But Coco couldn't produce those sounds.

Coco could understand them as well,

by seeing somebody sign or hearing somebody produce speech, but Coco couldn't produce it with her voice.

And so what's going on there is that a number of species, not all of them, a number of species have motor pathways in the brain where you can do learn gesturing, rudimentary language if you want and say with your lens, even if it's not as advanced as humans, but they don't have this extra brain pathway for the sound.

So they can't gesture with their voice in the way that they gesture with their hands.

No, it's not a crazy idea.

And in fact, you hit upon one of the key distinctions in the field of research that I started out in, which is vocal learning research.

Most vertebrate species vocalize, but most of them are producing innate sounds that they're born with.

That is babies crying, for example, or dogs barking.

And only a few species have learned vocal communication, the ability to imitate sounds.

And that is what makes spoken language special.