Dr. Erich Jarvis

When people think of what's special about language, it's the learned vocalizations.

That is what's rare.

So all the things you talked about, the breathing, the grunting and so forth,

A lot of that is handled by the brainstem circuits, you know, right around the level of your neck and below, like a reflex kind of thing.

Or even some emotional aspects of your behavior in the hypothalamus and so forth.

But for a learned behavior, learning how to speak, learning how to play the piano, teaching a dog to learn how to do tricks is using the forebrain circuits.

And what has happened is that there's a lot of forebrain circuits that are controlling learning how to move body parts in these species, but not for the vocalizations.

But in humans and in parrots and some other species, somehow we acquired circuits where the forebrain has taken over the brainstem and now using that brainstem not only to produce the innate behaviors or vocal behaviors, but the learned ones as well.

Amongst the primates, which we humans belong to, we are the only ones that have this advanced vocal learning ability.

Now, it was assumed that it was only Homo sapiens.

Then you can go back in time now, based upon genomic data, not only of us living humans, but of the fossils that have been found for Homo sapiens,

of Neanderthals, of Denisovan individuals, and discover that our ancestor, our human ancestors, supposedly hybridized with these other hominid species.

And it was assumed that these other hominid species don't learn how to imitate sounds.

I don't know of any species today that's a vocal learner that can have children with a non-vocal learning species.

I don't see it doesn't mean it didn't exist.

And when we look at the genetic data,

from these ancestral hominids that, you know, where we can look at genes that are involved in learned vocal communication, they have the same sequence as we humans do for genes that function in speech circuits.

So I think Neanderthals had spoken language.

I'm not gonna say it's as advanced as what it is in humans, I don't know.

But I think it's been there for at least between 500,000 to a million years.