The Birth of the Brain

Dr. Josh Stout's theories on how we got such large brains and what might this mean.

Episode Transcript

(00:13):
Friday,
September
22nd.
This
is
our
second
episode. 10 00:00:19,270 --> 00:00:00,-01 Dr. Stout:
Hi,
I'm
Dr.
Stout.
Today's
episode
is
all
about
the
growth
of
the
brain
and
how
we
got
such
large
brains.
We've
been
talking
about
AI
in
general
mind,
body

(00:33):
evolution.
And
what.
What?
What
does
that
mean?
I
think
of
the
evolution
of
the
mind
and
body
as
completely
a
single
thing
that
has
happened
to
us
or
we
have
made
happen.
And
this
is
often
seen
as
separate
ideas,
and
I
want
to
really

(00:54):
bring
them
together
into
a
sort
of
single
concept
and
then
unite
it
with
the
implications
for
our
evolution.
So
we
often
as
biologists
just
think
about
particular
aspects
of
our
physiology
and
how
they
might
have
happened
through
evolutionary
history,
but
we
don't
really
think
about
what
that
means
for
our
overall
health
and
how
we
should
be
living.

(01:14):
So
I
want
I
want
to
focus
on
both
of
these
things
at
the
same
time,
the
evolution
of
our
mind
and
of
our
physiology
and
how
that
will
affect
our
health.
So
last
week
we
were
looking
at
as
we
left
the
rainforest
and
we
became
bipeds.
So
it's
sort
of
our
first
4
million
years
of
evolution.

(01:35):
And
what
that
had
done
for
our
mind.
So
our
minds
were
ever
so
slightly
larger.
Instead
of,
say,
about
350
cc
brain
in
a
chimpanzee
was
maybe
450
brain
in
an
australopithecine.
Our
teeth
got
really
tough,
so
we
developed
jaws
that
were
great
for
chewing
and
we
developed

(01:56):
a
bipedal
gait
so
that
we
could
walk
long
distances
without
expending
too
much
energy.
So
this
was
the
time
when
we
were
really
developing
a
a
goal
in
our
physiology
for
efficiency
and
for
storing
every
possible
calorie
that
we
would
get
and
not
expanding
it
at
all
and

(02:17):
whenever
we
could.
So
that
was
pretty
much
the
scene
for
the
first
4
million
years.
But
then
things
began
to
change
and
it
was
another
rather
abrupt
change,
much
like
coming
out
of
the
jungle
made
us
bipeds.
It
was
a
moment
where
we
entered
a
new
evolutionary

(02:38):
niche,
where
we
suddenly
acquired
large
brains
and
what
could
have
been
driving
this.
So
we
were
already
quite
good
at
finding
our
foods.
We
were
good
at
social
interactions.
We
could
lie
to
each
other,
we
could
detect
lies.
We
had
large
territories.
We
would
have
been
able
to
work
together.
And

(02:58):
we
can
see
all
of
these
things
in
chimpanzees.
So
these
are
things
that
our
brains
were
already
good
at.
What
was
what
was
driving
the
next
change.
So
first
of
all,
it
was
the
beginning
of
the
ice
Age.
So
there
was
a
another
major
climactic
impact.
Things
got
much
drier,
so
things
were
even
worse.
And
so
we
were
already
sort
of
the
the
the
the
poor
relatives
of
chimpanzees

(03:18):
out
on
the
Serengeti
without
fruit,
but
having
to
dig
for
everything.
And
now
things
got
even
harder.
And
so
we
turned
to
a
resource
that
was
not
fully
exploited
out
on
the
Serengeti
and
that
was
scavenging.
We
became
obligate
scavengers

(03:38):
and
we
started
eating
a
lot
more
meat
in
our
diets.
And
so
the
technologies
that
would
have
been
developing
at
this
time
were
the
sharp
stones.
So
Australopithecines
would
have
had
very
simple
tools
which
wouldn't
left
any
any
any
particular
remains
behind
sticks,

(03:59):
maybe
maybe
some
chipped
rocks.
There's
a
few
out
there
that
people
think
might
have
been
purposely
chipped
for
for
a
reason.
And
we
know
that
there
is
even
monkeys
that
will
use
stones
to
crack
nuts
and
things
like
that.
So
the
idea
of
stone
tools
and
sticks
wood
would
have
already
been
in
our
lineage.
But
starting
around
2
million
years
ago,
you
see
a
huge

(04:19):
expansion
in
brain
volume
up
to
around,
you
know,
six,
700
cc's.
And
this
coincides
with
sudden
arrival
of
stone
tools.
And
so
this
would
have
allowed
a
new
source
of
of
calories.
We
would
go
to
a
carcass
more
able
to
slice
it
open,
and

(04:39):
we
would
have
gotten
things
that
other
animals
couldn't
get.
So
we
could
cut
through
a
thick
hide
that
even
a
hyena
wouldn't
be
able
to
get
through
an
elephant's
hide,
probably
for
a
couple
of
days.
But
a
sharp
rock
can
get
in.
And
then
we
would
have
been
able
to
crush
a
bone
of
a
larger
animal,
like
a
like
an
elephant
or
a
rhino

(04:59):
that
even
a
hyena
wouldn't
be
able
to
bite
through.
And
so
one
of
the
main
things
that
we
encountered
would
have
been
the
muscle
meat.
We
would
not
have
been
able
to
get
as
much
in
the
way
of
of
organ
meat
is
probably
why
we
don't
like
it.
Most
carnivores
love
organ.
Meat
has
a
lot
more
fat
in
it,
but
it
doesn't
preserve
well
while
sitting
out

(05:19):
on
the
hot
African
sun.
And
so
meats,
dried
meats,
this
is
what
we
started
to
to
look
for.
And
bone
marrow.
Bone
marrow
is
very
fatty
and
would
have
been
a
great
source
of
calories
for
our
brain.
Big
brains.
But
there's
one
more
capability
that
we
we
really
need
to
think
about
that
makes
us
human
and
that
is
our
ability
to
throw.
We
don't

(05:39):
think
about
it
as
central
to
being
human
on
the
way.
We
do,
say
our
large
brains,
but
it's
actually
directly
connected
to
our
large
brains
as
we
are
developing
to
use
the
the
left
hemisphere
of
our
brain
is
getting
particularly
eye

(06:02):
selected
for
and
we
become
handed.
But
this
this
region
of
our
brain
that
eventually
becomes
the
language
region
is
also
the
region
that
controls
throwing
and
targeting
systems.
So
I
think
that
the
growth
of
the
brain
wasn't
just
about
tool
use
tools
enabled
the

(06:22):
growth
of
the
brain
and
the
growth
of
the
brain
enabled
tools.
But
what
I
think
got
it
going
was
throwing
itself.
So
chimpanzees
throw,
but
they
don't
do
it
very
accurately.
It's
more
of
a
display
kind
of
arrangement.
And
if
you
imagine
us
out
on
the
Serengeti
without
any
defenses,
probably
the
Australopithecines
would
have
been
doing
inaccurate
throwing

(06:43):
from
a
very
early
time,
just
as
you
would
see
in
a
chimpanzee.
And
this
would
have
been
pretty
effective.
We
know
that
today
there
are
groups
in
Africa
that
are,
you
know,
herding
cows.
They
see
a
lion
coming.
They'll
just
throw
clods
of
dirt
at
it
and
the
lion
will
go
away
because
a
lion
can't
stand
having,
you
know,
something
hits
it
in
the
eye.
It
will
go
hungry
for
a
couple
of
days.
If
it
chips
a
tooth

(07:03):
on
something,
it
might
starve
to
death.
So
lions
not
going
to
mess
with
you
if
you
are
if
you're
if
you're
throwing
rocks
and
objects
at
it,
you
know
it's
going
to
run
away.
And
this
was
probably
our
number
one
defense
out
on
the
Serengeti.
And
I
what
we
see
in
association
with
the
brain
getting
larger
is
changes

(07:23):
in
the
body
itself.
And
so
some
of
these
would
have
been
for
any
kind
of
tool
use.
We
got
stronger
thumbs
and
shorter
fingers
that
allowed
better
gripping
so
now
we
could
grip
a
stick
and
hit
something
with
it.
But
this
is
also
the
grip
that
allowed
us
to
hold
a
stone
and
throw
it
properly.
Now,
why
do
I
think
this
is
not
just
a
matter
of,

(07:43):
say,
the
ability
to
hit
something
with
a
stick
or
a
club
or,
say,
hitting
one
rock
against
another,
but
it
was
actually
throwing
is
you
see
changes
in
the
shoulder
and
the
waist
that
are
specific
for
throwing.
If
you
think
of
a
baseball
pitcher
leaning
back,
rotating
the
waist,
Homo
erectus
could
do
this
in
a
way
that
the
Australopithecines
could

(08:04):
not
chimpanzees
could
not
chimpanzees
with
throw
sort
of
sideways
from
their
elbow,
whereas
a
baseball
pitcher
is
reaching
way
back,
are
asking
their
back,
twisting
their
waist.
That
flexibility
is
something
that
first
occurred
in
in
the
same
group
that
had
the
first
larger
brains.
And
so
there's
a
direct
connection

(08:24):
between
the
growth
of
the
brain
and
the
ability
to
throw
and
which
is
interesting
in
terms
of,
you
know,
thinking
about
health
aspects
that
while
we
have
evolved
as
these
very
efficient
machines
that
are
storing
calories,
we've
also
evolved
in
things
where
we
have
we
have

(08:44):
the
evolutionary
ability
to
produce
explosive
energy,
very,
very
quickly.
And
that's
directed
probably
not
the
way
modern
baseball
pitchers
are.
I
don't
think
it's
good
for
you
to
pitch
for
3
hours
at
100
miles
an
hour,
but
I
the
development
of
of
of
being
able
to
throw
something
targeted
ten,

(09:04):
20,
30
times
a
day
is
part
of
our
evolutionary
history.
And
I
think
it's
something
that
we've
neglected
in
sort
of
most
of
our
ideas
of
exercise.
Maybe
in
the
martial
arts,
you'll
get
explosive
power
like
that.
But
combining
it
with
full
rotation
with
the
idea
of
the
arm
flexing
backwards,
these
are
things
that
are

(09:25):
central
to
our
evolutionary
history
and
we
should
be
able
to
do
it
with
both
hands.
Now,
we
became
right
handed
probably
because
it
gave
us
just
a
slight
edge
to
the
left
side
of
our
brain
is
a
little
bit
better
at
targeting,
a
little
bit
better
coordination.
And
even
a
tiny
edge
was
going
to
give
you
a
big
advantage.
But
traditionally
people
have
been
able
to
throw
with
both
sides.

(09:45):
There
is
there
is
there
is,
you
know,
account
of
the
Europeans
landing
on
terrible
off
waggle
and
meeting
a
one
of
the
inhabitants.
And,
you
know,
of
course,
it
didn't
go
well.
And
so
the
first
thing
we
did
was
shoot
him
as
soon
as
we
saw
him.
And
he
he

(10:06):
then
started
picking
up
rocks
after
he'd
been
shot,
dodging
side
to
side,
throwing
with
both
hands.
He
took
out
three
people
before
they
brought
him
down.
Finally,
he
broke
a
guy's
collarbone,
knocked
two
guys
in
the
head,
knocked,
you
know,
they
were
they
were
he
almost
took
out
a
group
of
Marines
just
throwing
rocks
at
them.

(10:27):
So
this
was
something
that
that
that
people
could
do
really
well.
I
you
know,
there
are
still
people
out
there
who
can
who
can
just
go
out
and
kill
a
rabbit.
You
know,
I
had
friends
who
were
trekking
in
Mongolia
and
the
guy
said,
I'm
going
to
get
you
dinner.
And
they
looked
around
and
it
was
just
grassland
in
all
directions.
And
he
went
out
and
came
back
with
two
rabbits
and
he
just

(10:47):
thrown
rocks
at
them.
This
is
something
that
is
in
our
history,
and
we
certainly
know
a
baseball
pitcher
can
do
it,
but
it's
something
that
we
all
can
do,
maybe
not
at
that
level.
You
know,
I've
clocked
my
own
ability
to
throw
at
something
and
it's
not
great.
I
could
barely
break
40
miles
an
hour,
but
that
would
be
enough
to,
you
know,
throwing
a
baseball

(11:07):
sized
rock
would,
if
definitely
throw
it
accurately.
If
you
could
throw
it
actually,
you
know,
and
that
was
the
speed
I
from
about
20
or
30
feet,
I
could
mostly
hit
something
at
about
30
to
40
miles
an
hour,
which
is
not
great.
I
would
really,
really
hurt
whatever
I
was
throwing
it
out.
So
throwing
became
central
to
who
we
were.

(11:28):
But
then
we
have
to
think
about
what
happens
next.
You
know,
in
our
in
our
progression.
So
Homo
erectus
would
have
become
suddenly
one
of
the
top
dangers
out
on
the
Serengeti.
By
throwing
rocks
at
things,
we
are
now
able
to
stand
down
most
things
during
the
day,
at
night,
we

(11:48):
can't
see
as
well.
We
have
to
gather
and
find
some
sort
of
defense.
But
during
the
day
out
in
the
Serengeti,
we
can
throw
rocks
at
almost
anything.
And
most
things
are
going
to
be
deterrent,
not
an
elephant
or
a
rhino,
but
the
predators
are.
We're
now
much,
much
safer
from
the
predators
because
we
can
do
this.
It's
going
to
take
a
lot
more
lions
to
take
us
down.
And

(12:09):
so
what
became
our
new
threat
was
each
other.
And
so
now
we're
running
into
the
problem
of
we
have
to
fight
other
groups
of
humans.
And
so
what
this
would
have
been
called
was
confrontational
scavenging.
And
so
this
would
have
started
off.
You
see
the
birds
gathering,
you
run
to
the
carcass,
you
slice

(12:29):
a
piece
of
meat
from
the
carcass,
and
then
you
run
away
before
the
bigger
predators
get
there.
And
so
that
was
sort
of
the
general
model.
And
there
would
have
been
some,
you
know,
hyenas
and
lions
coming.
We
would
have
thrown
rocks
at
them,
cutting
off
that
piece
of
meat,
defending
it
long
enough,
and
then
going
away. 2157 00:12:43,790 --> 00:00:00,-01 Eric:
Because
you're
a
sharp
stone
and
you're
throwing
stones
become
important. 2169 00:12:49,060 --> 00:00:00,-01 Dr. Stout:
Well,

(12:49):
you
need
the
sharp
stones
to
cut
with,
but
you
also
need
things
to
to,
to,
to
to
throw
at
at
the
predators.
But
that
could
have
been
almost
anything.
Clods
of
dirt,
rocks.
But
yeah,
the
stones
would
have
hurt
more.
And
having
a
sharp
stone
would
have
been
particularly
useful
for
for
both
slicing
and,
you
know,
it
might
have
hurt
more.
But
when
it
came
to
other
members
of
our
genus

(13:10):
other
Homo
erectus
now
now
we
had
another
issue
they
could
throw
at
us.
And
so
you
have
two
groups
who
are
able
to
throw
clods
of
dirt
and
rocks
at
each
other.
And
this
is
when
I
think
we
combined
our
number
one
tool,
the
sharp
stone,
with
our
throwing
weapon.
And
so
we
sharpened
hand
axes
all
the
way
around.
So
they
were
like
throwing
stars.

(13:30):
And
this
wasn't
a
hunting
tool,
primarily,
in
my
opinion,
although
it
could
have
been,
I
think
they
would
have
been
generally
too
valuable
to
use
that
way.
Most
animals
that
you
could
kill
with
the
stone,
you
could
kill
with
just
a
random
stone,
but
a
sharp
stone
would
have
been
particularly
effective
against
a
another
human
who
was
standing
there

(13:50):
naked
screaming
at
you.
It
would
a
sharp
stone,
even
if
it
didn't
kill
them,
would
definitely
do
some
damage.
So,
you
know,
even
at
30
miles
an
hour,
not,
you
know,
your
best
throw,
if
you
just
winged
them,
they
would
be
in
big
trouble.
And
so
this
became
the
one
thing
that
we
made
more
than
anything
else
in

(14:10):
our
history
was
the
hand
axe,
because
it
was
our
knife,
it
was
our
weapon.
It
was
the
thing
you
went
away
with
holding
it
in
your
hand
because
you
had
to
have
some
way
of
defending
yourself.
And
I
think
it
led
to
some
interesting
aspects
of
our
psychology
so
that
we're
very
aggressive.
If
you
have
a
bunch
of
people
with
stones,
whoever
is
not
the
most
stones

(14:30):
and
is
throwing
them
well,
well
more
rapidly
is
going
to
be
winning
any
kind
of
contest.
So
having
a
pile
of
stones
and
a
lot
of
people
is
the
way
you
win
any
kind
of
territorial
battle.
But
what
happens
when
you
have
one
person
against
one
person?
Let's
say
it's
a
male
male
competition
for
a
mate.
So
you've
got
two
guys
fighting
over
someone
or
you've

(14:50):
got
just
got
two
guys
who've
met
each
other
at
the
edges
of
a
territory,
right?
So
they've
met
each
other
at
the
edge
of
a
territory.
Each
one's
got
their
hand
axe.
How's
that
going
to
go.
If
you're
the
first
one
to
throw
you
lose.
The
other
guy
is
going
to
run
right
up
to
you
and
hit
you
from
four
feet
away
with
his
hand
axe,
or
he'll
just
stab
you
because
you
don't
have
a
hand
axe
anymore.

(15:10):
And
he
and
he's
got
a
sharp
knife.
So
it
became
an
advantage,
an
evolutionary
advantage
to
not
be
the
first
one
to
throw,
particularly
in
interplay,
personal
interactions.
So
we
while
we
became
very
aggressive
and
we
got
really
good
at

(15:30):
throwing
sharp
things
at
each
other
and
were
able
to
defend
large
territories
this
way,
we
also
figured
out
a
way
to
not
kill
each
other.
And
this
is
something
you
see
amongst
dangerous
animals,
you
know,
throughout
the
animal
kingdom,
particularly
with
male
male
competition.
So
people
some
people
have
these
weird
ideas
that
hand
axes
were
for
display

(15:51):
and
that
the
beauty
of
your
hand
axe
was
to
attract
a
mate.
But
I
find
that
a
bit
of
a
stretch.
I
think
they
were
for
what
they
look
like
they
were,
they
were
knives
and
they
were
for
cutting
and
they
were
for
chopping
and
they
were
also
for
throwing.
And
if
you
think
about
male
male
competition

(16:11):
with
dangerous
animals,
you
have
things
like
the,
you
know,
the
elephant
seal
slashing
at
each
other.
But
they
make
sure
that
they
have,
you
know,
enough
blubber
so
they're
not
killing
each
other
when
they
slash
each
other's
throats,
you
know,
more
typically
you
can
think
of
something
like,
you
know,
bighorn
sheep
or
a
or
a
stag
to
stags
are

(16:32):
clashing
antlers.
Those
antlers
are
full
of
spikes
that
could
easily
kill
each
other,
but
they
run
head
on
to
each
other
and
then
it
becomes
a
shoving
contest
and
the
biggest
stag
wins
without
killing
the
other
one.
And
so
this
is
how
evolution
figures
out
ways
to
deal
with
the
danger
that
we
present
to
each
other
where
whoever
passes
on
their

(16:52):
genes
wins
the
competition.
So
everything
matters.
If
that
involves
killing
the
other
person,
so
be
it.
Passing
on
your
genes
is
all
that
matters.
But
if
we
kill
each
other
all
the
time,
we
won't
exist.
And
we
are. 2985 00:17:05,110 --> 00:00:00,-01 Eric:
None
of
us
will
get
to
pass
on
you. 2995 00:17:06,790 --> 00:00:00,-01 Dr. Stout:
And
we're
a
communal
species
and
we
live
in
communities.
And
so
if
you
wipe
out
the
rest
of
your
community,
you're
actually
starting
to

(17:12):
cost
yourself
something.
There's
it's
always
difficult
to
come
out
with
a
sort
of
a
a
way
for
defending
any
kind
of
of
group
evolution.
But
you
can
certainly
see
if
the
people
next
to
you
are,
you
know,
related
in
some
way
and
they
have
some
of
your
genes.
Not
killing
them
is
in
favor

(17:32):
for
your
evolution.
And
we
would
have
been
living
with
other
males
who
are
relatively
related
to
us.
And
so
killing
them
was
probably
a
bad
idea.
So
backing
down
became
something
that
we
were
able
to
do
to
scream
at
each
other,
wave
the
stones
back
and
forth,
and
then
step
back.
And
so
one
of
the
interesting
things
that
you
see
at
this
time
is
our

(17:53):
australopithecine.
Males
are
about
twice
the
size
of
the
females.
Homo
erectus
males
are
20,
25%
larger
than
the
females.
So
we're
becoming
in
some
ways
more
egalitarian.
If
you
think
about
the
way
different
primates
mate,
where
you
see
males
and
females
of
the
same
size,
that's
a
monogamous
relationship.

(18:14):
What
you're
seeing
here
is
something
I
probably
with
male
male
competition,
possibly
some
sort
of
polygamous
relationship,
multiple
wives,
sometimes
one,
sometimes
more
depends,
but
competition
even
between
males
for
mates
with
perhaps
the
ability
to
not
kill
each
other
for
it.
So
actually

(18:34):
backing
down
sort
of
a
mutually
assured
destruction
seems
to
be
basic
to
the
way
we
think
about
things.
The
interesting
thing
is
this
is
probably
when
when
a
more
advanced
form
of
language
is
also
developing.
So
as
tools
are
developing
and
we're
seeing
the
growth
in
the
left
hand
side
of
the
brain,
we're
also
developing

(18:55):
the
regions,
same
regions
of
the
brain
that
we
now
see
call,
you
know,
the
language
regions.
This
is
sort
of
a
more
old
version
of
thinking
about
the
brain,
but
the
linguistic
regions
of
the
brain
are
the
same
ones
that
control
eye
things
like
hand-eye
coordination
and
the
ability

(19:15):
to
do
small
movements
with
the
fingers
that
you
would
need
for
tool
use
and
swinging
a
hammer
or
something
like
that.
And
they're
definitely
the
same
regions
that
involve
throwing.
And
I
think
it's
really
interesting
the
way
the
way
language
is
built
with
a
subject
and
a
verb
and
an
object
kind
of
copies

(19:35):
the
way
we
think,
where
we
throw
something
at
something.
I
throw
the
rock. 3420 00:19:41,660 --> 00:00:00,-01 Eric:
Out. 3422 00:19:42,120 --> 00:00:00,-01 Dr. Stout:
At
the
other
person,
and
that
this
is
a
sort
of
grammar
that's
built
into
the
actions
themselves.
And
so
the
grammar
portions
of
the
brain
are
also
the
ones
that
control
targeting
a
hammer
onto

(19:56):
the
thing
you're
hitting.
These
are
the
same
the
same
regions
that
are
controlling
these
small
movements.
And
the
the,
the,
the
intent
behind
hitting
something
is
the
same
ones
that
are
controlling
things
like
syntax
and
word
formation.
It's
the
Broca's
and
Wernicke's
areas
of
the
brain
are
the
same
ones
that
are
controlling
a
lot
of

(20:16):
tool
action
and
in
my
opinion,
auto
throwing.
Now,
again,
these
are
this
is
old
ways
to
think
about
the
brain.
Like,
say
if
you
imagine
an
atom
is
something
with
a
nucleus
and
electrons
spinning
around
it,
you
are
about
a
hundred
years
or
more
out
of
date.
But
it's
a
good
way
to
think
about
an
atom,
right?
So
thinking
about
the
brain
with
language
regions
that
are
then
controlling
and
talking

(20:36):
to
each
other
in
particular
areas
like
this
is,
is
a
somewhat
out
of
date
way
of
thinking
about
the
brain.
But
but
it's
useful
and
useful
model.
It's
a
useful
model.
And
it's
and
it's
not
completely
inaccurate.
Right.
It
it
it
is
somewhat
true
and
can
can
be
used
that
way.
So
we
definitely
are
seeing
the
left
hand
side
of
the
brain
getting
larger.
We're
seeing
the
right

(20:56):
hand
side
of
the
body's
bones
getting
thicker.
So
they're
being
used
more.
We're
becoming
more
fully
right
handed.
And
we're
we're
probably
developing
the
ability
to
have
language
at
this
time
and
other
physiological
changes.
So
the
the
throat
is
starting
to
change.
A
chimpanzee
can
breathe
and
drink

(21:16):
water
at
the
same
time,
whereas
you
as
a
human
cannot
do
this.
And
more
humans
would
survive
if
we
could,
right?
So
we
have
to
get
the
Heimlich
maneuver
or
we
die
when
we
choke
on
something.
This
is
an
evolutionary
cost.
So
why
did
we
do
this?
Why
did
we
we
we
lowered
our
larynx,
we
lowered
our
voice
box.
And
probably
it
has
something
to

(21:36):
do
with
communication.
And
that
communication
was
very
important
to
us
or
we
would
have
not
taken
on
this
cost.
And
so
sort
of
piggybacking
on
this
development
of
the
brain
having
to
do
with
confrontational
scavenging,
having
to
do
with
throwing
sharp
rocks
at
each
other,
we
were
also
building
the
nature
of
language
into
our
brain.
And
so
it's

(21:57):
it's
built
on
what
we
were
doing,
the
idea
of
hitting
something
with
something
else.
It's
built
on
the
already
existing
Machiavellian
sort
of
ways
of
manipulating
each
other.
And
now
we've
done
this
into
our
display
activities.
We've
got
this
into
into
the
tools
we're
using
and
how
we
how
we
interact

(22:17):
with
each
other
has
all
been
associated
now
with
language.
And
so
now
we
can
do
with
sounds
coming
out
of
our
mouth.
What
we
could
only
do
physically
before
that.
So
the
way
a
chimpanzee
would
say
comfort
another
chimpanzee,
we
can
now
perhaps
do
with
sounds,
rig?
So
we
don't
know
exactly

(22:37):
when
language
is
starting,
but
we're
seeing
the
region
of
the
brain
and
we're
seeing
physiological
changes
that
one
would
expect
if
language
is
happening
at
this
time.
Right.
So
not
saying
that
chimpanzees
don't
have
very
fine
brains
that
are
very
good
for
social
interactions
and
that
they
are,
you
know,
a
fully
sentient
species,

(22:58):
but
they
don't
have
the
same
linguistic
capabilities
that
we
do.
Their
brains
simply
are
not
as
large.
There
are
many
things
they
can't
do
that
we
can,
such
as
chipping
rocks
with
a
pattern
and
a
form
that
you
can
actually
see
the
form
happening,
you
know?
So
this
is
probably
where
we're
getting
the
beginning
of
mental
images
that
we
can
then
copy
into

(23:18):
a
particular
shape.
All
of
these
things
having
to
do
with
the
beginning
of
abstract
language
where
we're
saying
sounds
that
represent
something
many
animals. 4095 00:23:27,070 --> 00:00:00,-01 Eric:
Can
do
this
now,
this
is
what
you
see,
the
beginnings
of
which
you
talked
about
in
the
in
the
last
conversation
when
we
began
to
imagine
the
tubers
under
ground. 4127 00:23:37,090 --> 00:00:00,-01 Dr. Stout:
Right.
So
what
we

(23:39):
well,
all
animals
have
some
way
of
modeling
the
world
around
them.
All
of
this
is
involving
imagination
in
some
way,
because
modeling
the
world
around
you,
in
your
brain
is
imagination.
But
yes,
now
this
is
coming
to
an
another
level
where
it's
not
just
imagining
how
I
can
fool
someone
else
with
my
ideas,
but
it's
it's
it's

(23:59):
imagining.
What
does
a
rock
look
like
when
I
look
at
a
rock?
How
am
I
going
to
get
this
hand
axe
out
of
the
rock?
Imagining
the
hand
in
the
rock
is
is
a
whole
nother
level
of
imagination.
And
so
it's
not
art
yet,
but
it's
definitely
a
concept
in
our
head
that
we
can
now
make
and
we
pass

(24:19):
this
down.
And
so
hand
axes
become
the
number
one
thing
that
gets
made.
We
see
them
everywhere
they
spread
across
the
world.
There
is
hand
axes
in
every
place
that
people
have
have
have
gone
because
this
was
what
we
made
for
the
next
2
million
years
or
so
everywhere.
And
interestingly,
if
you
go
to
some
of
these
sites

(24:40):
in
Africa
where
people
were
making
hand
axes,
you'll
find
them
just
heaped
on
the
ground.
Everywhere
you
look,
it's
just
piles
of
hand
axes.
And
so
this
would
have
been
associated
with
the
first
development
of
a
true
home
base
where,
you
know,
a
an
australopithecine
would
have
been
roaming
from
place
to
place.
There
were
probably
trees
they
liked
to
go

(25:00):
to
because
they
were
great
for
shade
near
a
river,
etc..
But
now
it's
worth
stockpiling
weapons
so
that
if
another
group
of
Homo
erectus
comes
along
and
you're
the
ones
with
a
pile
of
hand
axes,
you
can
throw
hand
axes
all
day,
How
many
hand
axes
can
they
have?
They
can
have
two,
right?
So
you
now
have
a
defensible

(25:20):
area.
It's
not
the
same
as
having
a
roof
and
walls,
right?
We're
not
in
houses
yet.
We're
not
even
in
tents.
But
having
a
defensible
area
with
a
giant
pile
of
your
weapons
gives
you
a
place
sort
of
that
is
that
is
more
significant
rent
than
the
rest
of
the
territory
around
you.
Right.
So
there
was
probably
shade,
there
was
probably
water.
That

(25:40):
was
a
reason
to
have
this
spot,
but
also
access
to
good
stones
and
then
building
up
a
pile
of
them
where
you
live
became
important.
So
this
is
also
building
up
the
idea
of
connection
to
a
place.
So
certainly
chimpanzees
would
have
had
territory,
but
with
the
development
of
language,
we're
starting
to
build
larger

(26:00):
communities
with
language.
We
can
we
can
we
can
interact
with
larger
groups,
we
can
defend
larger
places.
And
now
we're
connected
to
particular
places
to
to
to
the
land,
because
that's
where
our
hand
axes
are,
and
that's
where
we
get
the
rocks
that
we
use
to
make
them.
And
so
we
were
certainly
still
nomadic.
We're
moving
from
place
to
place.
We
probably
had
several
home
bases

(26:20):
that
we'd
move
through
seasonally
as
as
systems
change
and
as
weather
changed.
So
these
were
these
were
sort
of
a
combination
of
mental
and
physiological
changes
that
are
going
hand
by
hand,
hand
in
hand
at
the
same
time.
This
is
why
I
say
that
the
mind

(26:40):
and
the
body
are
not
two
separate
things.
These
are
happening
absolutely
together.
So
as
we
get
changes
in
the
shoulder
blade
that
allows
us
to
bring
our
hand
behind
our
own
bodies,
we're
also
getting
a
larger
brain
that
allows
us
to
talk
to
each
other.
And
so
we're
getting
the
ability
to
have
a
a
mental
concept
that
we

(27:00):
can
shape
in
language
in
some
way
so
we
can
say
a
word
in
our
head
and
then
we
can
say
it
out
loud.
Right?
So
chimpanzees
have
communication,
but
they
probably
don't
have
this
sort
of
secondary
linguistic
aspect
in
their
own
brains
when
they're
doing
it.
It's
hard
to
say
what
humans
do.
We
have,
you
know,
two
levels.
We
have
the
underlying
thoughts
and

(27:20):
we
have
the
language.
Our
thought
is
not
simply
language.
Language
happens
after
thought,
but
we
organize
our
thoughts
with
language.
And
so
this
is
this
is
now
a
capability
that
we're
developing
and
we're
able
to
now
build,
as
I
said,
communities
and
home
bases
and
a
group
of
people
who
interact

(27:41):
with
each
other
with
language.
And
so
now
this
is
how
we,
we,
we
we
comfort
each
other,
how
he
threatens
each
other,
how
we
organize,
right.
So
our
our
hunting
ability
becomes
much
more
advanced
at
some
point
in
sort
of
the
first
million
years
of
of
Homo
erectus,
we
start
developing
these
new
capabilities

(28:01):
where
we
go
from
being
confrontational
scavengers,
running
out
to
a
carcass,
scaring
off
the
other
scavengers,
scaring
off
the
older
humans,
stealing
a
piece,
running
back
to
actual
hunters,
and
we
start
becoming
more
organized
and
we
can
chase
animals
to
a
particular
direction
over
a
cliff.
Maybe.
I
don't
know
if
Homo
erectus
was
doing
that
much,
but
certainly
we
could.
We
could
organize
ourselves

(28:22):
to
to
maybe
even
run
down
animals. 4991 00:28:24,790 --> 00:00:00,-01 Eric:
Because
of
language. 4995 00:28:26,290 --> 00:00:00,-01 Dr. Stout:
Because
of
language,
and
because
of
our,
you
know,
ability
to
talk
to
each
other
about
what
we're
going
to
do,
make
plans
the
same
way
we're
able
to
pass
on
the
concept
of
hand
handshakes.
Now,
a
lot
of
this
stuff
can
be
done
without
language,
right?
So
a

(28:42):
wolf
can
organize
a
wolf
pack
and
go
off
and
do
a
hunt
without
without
language.
I
suspect
I
could
make
a
hand
axe
If
I
could
make
a
hand
axe.
They're
not
that
easy.
But
someone
could
make
a
hand
axe
and
you
could
learn
how
to
do
it
without
ever
using
language.
Right?
You
could
just
copy
their
activity.
But
language
makes
all
of
this
easier.
You
can
say,
No,
no,
no,
not
like

(29:02):
that.
Right?
You
you
you
can
do
things
with
language
that
is
more
difficult
without
it.
Now,
I
don't
think
we
had
the
fully
developed
language
that
we
do
today.
It
wasn't
it
wasn't
at
that
level
yet.
And
we
can
see
it
in
the
physiology.
So
I
mentioned
the
throat
dropping.
This
happens
over
the
course
of
a
human's
life.
So
we
start
off
as
babies

(29:22):
who
can
nurse
and
breathe
at
the
same
time.
That's
important,
right?
And
we
have
little
turned
up
noses
and
we
can
and
we
can
suck
while
we
breathe
through
them
and
we
don't
drown.
So
over
the
course
of
our
lifetime,
or
all
the
way
through
puberty,
our
larynx
is
dropping
and
we

(29:42):
are
learning
to
form
words.
So
a
four
year
old
having
difficulty
with
words.
Some
of
it
is
simply
they
don't
have
the
apparatus
that
they
will
later
in
life
to
make
those
sounds.
And
so
we're
seeing
this
in
the
in
Homo
erectus.
So
Homo
erectus
would
have
had
a
throat,
something
like
a
six
year
old.
So
not
fully
developed
by
modern
human

(30:03):
standards,
but
certainly
one
that
is
they
would
not
have
been
able
to
eat
and
drink
at
the
same
time
area
and
breed
at
the
same
time.
And
they
would
have
been
able
to
make
more
complex
sounds
than
they
did
before
their
larynx
drops.
So
we're
seeing
a
physiological
advancement
in
language,
but
it
is
not
physiologically

(30:23):
complete
yet.
They
they
don't
have
the
same
kind
of
of
innovation.
They
don't
have
we
have
really
I
we
have
really
precise
control
of
our
of
our
of
our
chest,
of
our
tongues
of
of
of
the
apparatus
for
speech.
This
is
not
as
developed
yet
in
Homo

(30:43):
erectus.
So
they
would
have
definitely
not
have
any
opera
singers.
They
would
have
had
the
diaphragm
control,
they
wouldn't
have
had
the
breath
control
to
make
the
kind
of
sounds
that
are
modern
human
can
make.
But
they're
on
their
way.
They're
vastly
beyond
what
a
chimpanzee
could
do.
And
the
brains
are
about
twice
the
size
of
chimpanzees
at
this
time.
So,
you
know,
700
cc's
as
opposed

(31:03):
to
350.
So
this
is
a
major,
main,
major
change.
And
it's
a
major
change
in
our
way
of
life.
We
are
now,
as
I
said,
meat
eaters.
We're
not
just
I
digging
up
roots
and
occasionally,
you
know,
catching
a
lizard,
but
we're
on
purpose
going
for
large
animals
because
these
are
the
ones
that
are
less

(31:23):
that
the
predators
are
less
able
to
get
into
and
take
away.
Right.
So
if
something
catches
a
rabbit,
we're
not
going
to
get
any
of
that
rabbit.
But
if
something
kills
an
elephant
or
an
elephant
just
dies
so
nothing
can
get
through
the
hind.
So
we
might
be
the
first
to
get
through
that
high
if
something
else
is
sort
of
burrowed
into
its
stomach
and
has
eaten
all
the
contents
of
the
stomach,
we

(31:43):
can
still
cut
away
the
hide
and
get
to
the
meat.
We
can,
with
a
stone
tool,
take
out
the
joints
in
the
leg
and
take
out
a
whole
leg
and
run
away
with
that.
So
where
we're
eating
the
things
other
things
don't
like
to
eat,
we're
able
to
get
at
them
in
ways
other
things
aren't
able
to
do.
And
then
we
can
take
a
big
rock
and
we
can
break
a
bone
with
it.
We
even
a
bone
of
an
elephant
and

(32:03):
get
to
the
very
rich,
fatty
bone
marrow
inside.
So
these
are
our
new
techniques
that
we
develop.
The
basically,
the
moment
our
brain
increases,
we
develop
these
techniques.
And
we
couldn't
have
gotten
these
techniques
without
our
brain
increasing.
I
think
the
piggyback
chicken
and
egg
here,
I
think
the
piggybacking
started
with
throwing
that
it
was
something
we
were
doing
already.
And
as

(32:24):
we
got
better
at
throwing,
we
could
get
carcasses
more
easily
because
we
could
scare
off
the
predators
simply
by
throwing
clods
of
dirt
at
it,
something
that
chimpanzees
already
do.
So
it's
already
in
our
behavior.
We
got
incrementally
better
at
this,
and
then
suddenly
we
got
a
lot
better
when
we
combined
it
with
sharp
things
that
could
cut
into
the
into
the
meat.
So

(32:44):
just
like
moving
out
of
the
Serengeti,
there
wasn't
a
million
years
of
slowly
becoming
a
biped.
There
was
We
lived
in
the
jungle
and
then
suddenly
you
see
several
bipeds
happening
at
the
same
time.
There's
almost
no
intervening
moment.
So
you
have
a
whole
bunch
of
bipeds
living
out
on
the
Serengeti
for
4
million
years,
chewing
roots,
and
then
suddenly
one

(33:04):
of
their
brains
expands
roughly
double.
And
in
like
a
hundred,
200,000
year
period,
we
go
from
sort
of
transitory
Homo
habilis
to
Homo
erectus,
and
then
we
stay
that
way
for
the
next
2
million
years. 5938 00:33:17,830 --> 00:00:00,-01 Eric:
A
transition
takes
place
over
a
hundred
million
years. 5948 00:33:20,740 --> 00:00:00,-01 Dr. Stout:
100,000. 5950 00:33:21,640 --> 00:00:00,-01 Eric:
So
100,000
years,
yes. 5955 00:33:23,680 --> 00:00:00,-01 Dr. Stout:
And
then
we
stay
that
same

(33:24):
way,
more
or
less
for
about
the
next
2
million
years,
with
our
brains
slowly
growing,
but
our
physiology
just
staying
kind
of
the
same. 5987 00:33:32,110 --> 00:00:00,-01 Eric:
It's
such
rapid,
rapid
change.
This
slowed
by
stasis. 5997 00:33:36,430 --> 00:00:00,-01 Dr. Stout:
This
seems
to
be
the
way
evolution
often
happens
when
when
a
new
ability
is
developed,
you
select
for
that
ability
very,
very
quickly.

(33:44):
And
then
once
you've
solved
the
problem
you're
trying
to
solve
being
a
biped
or
being
intelligent,
now
you
have
a
new
evolutionary
niche
that
you
fill,
and
so
you
then
try
and
maximize
the
ability
within
that
niche,
but
your
evolution
slows
down.
And
so
sometimes
this
is
called
punctuated
equilibrium.
Some
people
call
it
evolution
by
jerks.

(34:05):
It's
like
a
just
sudden,
like
something
changes
and
then
you're
sort
of
at
a
new
level.
It's
not
that
it's
in
a
moment.
It
could
be,
but
mostly
it's
not.
In
a
moment.
A
momentary
change
would
be
something. 6121 00:34:15,820 --> 00:00:00,-01 Eric:
Thousand
years
is
100,000
years. 6127 00:34:17,380 --> 00:00:00,-01 Dr. Stout:
Yeah.
It's
time.
It's
time.
Yeah.
Sometimes
there
are
things
when,
say,
let's
say,
two
chromosomes
get
fused
together.
You
can't.
You
can't.

(34:25):
That
that's
a
new
species
in
a
moment.
And
then
evolution
could
after
that.
So
sometimes
that
could
happen
where
it
really
is
instantaneous.
But
I'm
not
talking
about
that.
I'm
talking
about
a
series
of
of,
you
know,
incremental
changes,
but
they're
selected
for
so
heavily,
whoever
throws
the
rocks
better
gets
more
food,
and
then
that
quickly
turns
into
whoever
throws
the
rocks
better,
gets

(34:45):
more
food
and
more
mating
opportunities
because
we
compete
with
each
other.
And
if
you're
getting
food
and
mating
opportunities,
evolution
loves
you.
And
so,
you
know,
we
went
in
that
direction
very,
very
quickly.
Yeah.
All
right.
I
guess
I
will
go
on
in
this
direction.
So
next
week
I'll
be
talking
about

(35:06):
AI,
further
development
of
the
imagination,
and
we'll
get
into
things
like
art
and
aesthetics
and
how
we
got
up
to,
you
know,
modern
language
as
it
is
today
and
what
kind
of
things
that
would
have
been
associated
with
how
we
lived,
what
our
diet
would
have
been,
what
kinds
of
exercise
we
would
have
been
doing
at
this
time,
say

(35:27):
200,
100,000
years
ago
in
that
range. 6341 00:35:30,370 --> 00:00:00,-01 Eric:
All
right.
Excellent.
Well,
thank
you
very
much.
See
you
next
time.