Kind: captions
Language: en
So that brings me to another research
study. Yeah.
>> That I heard I think a year ago. Uh I
don't think the result was a year ago. I
think I heard someone speaking of it a
year ago. And what that was
>> is that it was originally thought that
chimpanzees don't have the mechanical
equipment for producing speech. But then
some study found well actually they do.
They just don't have the brain for
>> That's right. That's right. Yes. Okay.
Yeah. Yeah. This has been a debate over
a number of years. uh and it's it
includes you know what what what in the
in the biology in the brain in the
muscles and so forth makes speech
special
>> right
>> and there are a number of different
hypothesis and this is one of them
>> that there's a difference in the
musculature
>> of the larynx or that it's more
descended in humans
>> and allowing greater air space in the
vocal tract to produce a greater variety
of sounds. A lot of this has been proven
not to be the case.
>> Ah,
>> all right. So, um, a colleague of mine,
Tukuma Fitch,
>> uh, blows air through post-mortem,
you know, larynxes of humans,
>> of chimpanzees, of monkeys. And you get
similar kinds of sounds.
>> Oh wow. that you get in speech when you
you know phonms we call them different
kinds of phonms
>> that you get when you blow air even
through a post-mortem larynx.
>> Wow.
>> But um but when it's inside the living
animal of a of a monkey, you you can't
get the speech sounds out of it. And
why? Because it's not in the muscles,
it's in the brain that makes that
difference between being able to speak
>> and not speak. So is it the case that
you know you have birds, you have
mammals, you know a different part of
the family tree. So are the same
outcomes being achieved by different
brain areas or is it that
>> there's some ancient ancestor that
predates birds and mammals that had this
particular equipment and now uh it's
being used in different ways to get the
the the
>> well well discovering these gene
specializations uh where the regulation
is different helped us answer some of
the questions that you just asked.
>> Okay. And putting it all together, the
story that you know I've come up with is
that um
all vertebrates have the ability to
learn how to move.
And what happened in us humans and the
song learning birds, dolphins I believe
as well is that these brain pathways
that control learned movement of the
body are are duplicating themselves to
control the hands, the chest, the feet
and so forth during embryionic
development. And in us humans and the
vocal learning birds, the brain pathway
duplicated one more time
>> and now got hooked up to the muscles of
the larynx and the jaw and so forth to
control uh sound production to learn how
to imitate sounds. And we already have
auditory input from the hearing pathway
going into the movement pathway. If you
got to you're going to learn how to
move, you got to learn to move to sounds
that you hear, learn to move away from
sounds and so forth,
>> right? And so so this auditory input is
already happening.
>> Yeah.
>> Uh the ability to understand complex
sounds is already there.
>> Yeah.
>> All right. I think consciousness is
already there.
>> And yes, language evolved more recently.
Spoken language. Uh so uh we call this
bra uh brain evolution by brain pathway
duplication.
>> Oh
>> like gene duplication. Yeah. A whole
brain pathway duplicates, connects to
the vocal organs.
>> Wow.
>> And now you get spoken like speech
basically.
>> Holy cow. Talking about taking something
that already exists and
>> Yeah. Yeah.
>> And so this happened multiple times. Uh
and when each time that it happened, a
certain set of genes change in their
regulation
>> in humans and in the song learning
birds. We call that convergent
evolution. Right.
>> All right. Because their closest
relatives like us for chimpanzees,
we are their closest relatives. I mean,
they're our closest relatives too, you
know. So, chimpanzees living surviving
reliving surviving
>> relives. Yes, that's right.
>> Um, let's say what we call subassene
birds for songirds or falcons for
parrots. uh none of them have these
brain pathways or this gene expression
specializations
>> that we see in uh in the vocal learning
birds. So we think the whole brain
pathway duplicated the gene
specializations uh then were evolved uh
in a convergent manner.
>> I see.
>> And so it suggests that if vocal
learning and spoken language were to
evolve another half a million years from
now say in a crocodile
>> Yeah.
>> Right.
>> Yeah. or a chimpanzeee,
>> right?
>> I could tell you what the brain pathways
are going to look like and I can tell
you which genes are going to change.
>> You It's predictable.
>> It's predictable.
>> Wow.
>> That's right.
>> Because you know what the the the
rough material they have to start with
is already.
>> That's right. Well, because we we've
already seen it multiple times in
multiple spec lineages of species. um
that there seems to be a basic principle
of a a fundamental set of genes
>> that's going to that needs to change in
order to get vocal limitation.
>> Right.
>> All right. If and in in the songirds
that was like 30 million years ago.
>> Yeah.
>> In parrots that was 50 million years
ago.
>> In humans it was the most at a million
years ago. Okay. with I think with some
common ancestors with Neanderthal and
Denisovven archaic humans.
>> So it would have been Homo erectus then
that that had language first.
>> Um
I we we might go that far back that
would be a prediction.
>> Okay.
>> But certainly you know uh uh the
homminids as we call them.
>> Right. Right.
>> Uh which are modern humans and archaic
humans.
>> Right. Right. Right. Wow. So you brought
up this idea between hearing
speech and motion.
>> So, this is something my niece was born
in 1984 and I was in high school
>> and you know what in rap was new.
>> Y
>> so I used to sit around
>> beating out beats and my little niece as
soon as she could sit up she would bob
and dance to the little beats I was
making. And at the time I was a high
school musician as well. It occurred to
me I was like what is this thing with
music? Why is it that we respond
in such a way? We get emotional. Our
bodies move almost without us thinking
about it to these sounds. Like what the
hell is going on? Why? Because it seems
like a lot of species are completely
they don't respond that way. Yeah.
Right. Right.
>> Yep.
>> Have you guys figured that out? What the
>> Yeah. Uh what one of the remarkable
things discoveries in the last you know
10 to 15 years is that um it's been
found that only vocal learning species
can learn how to dance.
>> And when I say dance I mean rhythmically
to a beat of sound in music. Uh and why
is that the case?
>> Yeah. Um once uh I in order to evolve
the ability to imitate sounds, you need
the auditory input going through your
ears to have rapid integration with the
movement pathway that's controlling your
muscles to produce those sounds.
>> All right? You need that tight auditory
motor integration as we call it. I think
that once that tight integration
occurred for the vocal organs, it
contaminated the rest of the movement
pathway.
>> Wow.
>> To now process sound
uh in a way that controls movement or
influences movement of the other organs.
>> Wow.
>> Of the other body parts or muscles that
control the body, the the arms, the
legs. And so yes,
you know, [laughter]
you know, your little niece, right, is
has something special going on that they
find in these humans and uh and other
vocal learning species. And so I think
it's a side effect of having vocal
learning. The ability to dance came
about because of our ability to speak.
>> Wow.
>> Yeah.
>> That is so deep. And what's what's
remarkable
uh is that there are several kinds of
abilities that came along either for the
ride or that are evolved that are
correlated with our ability to speak.
>> And that's one of them is the ability to
dance synchronously to a beat of music.
>> Another is problem solving.
>> We found that the more advanced vocal
learning abilities you find, let's say
in a songird species, the better you are
at problem solving.
All right.
>> Interesting.
>> And so there's some cognitive uh ability
there. And putting all this together uh
these abilities that are special in
vocal learners, I call it the uh vocal
learning cognitive complex.
>> And I'm including dancing in that
cognitive complex.
>> Wow. Wow.