Cosmos: Possible Worlds (2014–…): Season 2, Episode 11 - Shadows of Forgotten Ancestors - full transcript

An exploration into the similarities and differences of humans and animals.

TYSON: If an
extraterrestrial scouting party
were to survey Earth,

what would they make of us?

Who are we?

Are we as a species
capable of fundamental change?

Or is there
something in our DNA
that will determine our fate?

(groaning and moaning)

(speaking in native language)

TYSON: Do the dead hands of
forgotten ancestors impel us

in some direction
beyond our control?

Can we free our children from
the demons that torment us and

haunt our species?



Can we be trusted
with our own future?

Since the civilization
of Ancient Persia,

and probably even before,
we've wondered if there's

something about human nature
that contains the seeds of
our destruction.

(theme music plays)

♪ ♪

♪ ♪

TYSON: If there are
places on Earth that
are sacred to our species,

surely this
must be one of them.

The earliest site we
know of where fire was
tamed for human needs.

More than a
million years ago, here,

in what is today known as
Wonderwerk Cave in South Africa,

our ancestors gathered
and first kindled the hearth
of human culture.

Every human being alive
today on Earth is a member



of the species Homo sapiens.

The so-called "wise ones."

And our forbearers here
tonight are Homo erectus,

"those who stood up."

They're not yet us, but
we carry them within us.

We don't know much about them.

We think they took
care of each other when
they became old or ill.

We know they were
skilled toolmakers.

It was around fires
such as this one that we
began to cook our food.

To tell each other stories.

And to create a shared
learned identity with our kin.

Had life and humans first
evolved only hundreds or even

thousands of years ago, we
might know most of what's

important about our
past and how we came
to be the way we are.

But instead, our
species is hundreds of
thousands of years old.

Homo erectus, a
couple of million.

Primates, tens of millions.

Mammals, more than 200 million.

And life, about
four billion years old.

All but a few of our ancestors
are wholly unknown to us,

and we sift through the Earth
to find the bits of ash and

animal bone that are
the only surviving
evidence of our humanity.

We only began living
with a future in mind,

consciously leaving a detailed
record of who we were and what

we believed around
5,000 years ago.

And yet, one thing remained
constant from Homo erectus to

the greatness of
Ancient Persia.

Our fascination with fire.

And this was true
here at Persepolis,

a magnificent complex built
by the Persian emperors of the

sixth century BCE,

when Persia was the
only superpower on Earth.

These great kings worshipped
a God named Ahura Mazda,

whose origins in
time are lost to us.

His prophet was Zoroaster.

Every Zoroastrian temple
was consecrated to fire.

It played the central
role in Zoroastrian worship,

symbolizing both the purity
of their God and the light

of the illuminated mind.

Tending an eternal flame
through the centuries was one

of the few ritual obligations
of the Zoroastrians.

They chose this first
truly human achievement,

the domestication of fire,

as the focal point
of their worship.

The God Ahura
Mazda didn't ask much.

He didn't want your
ritual sacrifices,

he didn't want your money.

All he asked of human
beings was good thoughts,

good words and good deeds.

But for some reason,
most people couldn't fulfil

these simple requests.

Often they had bad
thoughts and said evil things,

and some of them committed
crimes that were evil.

Why?

It was all because of
Ahura Mazda's polar opposite,

Angra Mainyu.

This is where the
devil was born.

From his short horns,
to his hooves,

Zoroastrianism was the
dominant religion from Greece

to India for 1,000 years.

No wonder they were so
influential on the religions

that came after.

For the Zoroastrians,
all the evil in the world,

the crimes
committed by humans,

as well as the catastrophes of
natural disasters and disease,

were the results of Angra
Mainyu's unceasing mischief.

Their God, Ahura Mazda,

looked to human beings to
help him defeat the devil.

Any person by their actions
could tip the scales of the

whole future of the universe
in either the direction of
good or evil.

In this prescientific world,

when evil reared its ugly head,

what better way to understand
it than demonic possession?

(barking)

This is not a story
of good and evil,

of the struggle
between a God and a demon.

It's actually just a story
of a predator and its prey.

In this case, the predator
is microscopic and it's been

incubating in its victim.

Diseased microbes can
be formidable predators.

Not only attacking
and eventually killing,

but also taking
over their hosts.

Changing their behavior
to spread their
microorganisms to other hosts.

We're in the
bloodstream of that poor,

unlucky dog, who,
through no fault of his own,

just because of a chance
encounter with a rabid bat,

now finds himself
the main character in a
zombie horror story.

Those bullets are
the rabies virus.

On being injected into the
bloodstream of this placid,

people-loving dog, they
head to the dog's brain,

right to the limbic system,

where the control
buttons for rage reside.

By attacking the nerve cells,

the rabies virus
is converting the poor animal

into a marauding, snarling,

vicious predator without
loyalties or love for anyone.

(baby crying)

Rabid animals can be fearless.

Now that the limbic
system has been conquered,

another detachment of rabies
viruses are dispatched to the

saliva manufacturing
machinery in the dog's throat.

Their assignment is to
put it into overdrive,

while paralyzing the
nerves for swallowing.

This maximizes the chances
for the infected saliva

to leave the dog and
invade the next target.

But how is such a degree
of tactical coordination

possible by a virus?

How can a virus know which
part of another creature's

brain is the seat of anger?

We ourselves didn't figure
that out until very recently.

This is the power of evolution
by natural selection.

Given enough time,
a random mutation,

no matter how
highly specialized...

Say, a virus' ability to
paralyze a victim's throat,

will take hold.

If it enhances the
virus' chance of survival,

it will be passed on.

All it needs in every
generation is a victim to

carry the disease.

Keeping that
wicked flame alive.

The transformation from
the family guardian to the

ferocious wild-eyed
demon is complete.

The dog is furious,
although he has no idea why.

(speaking in native language)

A helpless pawn of
the viruses within him,

he can't resist the
impulse to attack.

If the attack is successful,

the viruses in the
dog's saliva will enter the

bloodstream of the
victim through the
lesion or laceration.

And then, they'll set about
taking over this new victim.

The rabies virus is a
brilliant manipulator.

It knows its victims and
how to pull their strings.

It coordinates its attack,
circumventing defenses,

infiltrating, outflanking,
accomplishing a coup d'état

within its prey and turning
the most gentle among us into

the most violent.

We are at the mercy
of unseen forces.

Viruses, microbes,
hormones, our very own DNA.

Where does the programming
end and free will begin...

(buzz)

If it ever does at all?

TYSON: Do honeybees
have free will?

When a honeybee dies, it
releases a special chemical.

It's a death pheromone that
has a characteristic odor,

signaling its fellow bees
to remove it from the hive.

The death
pheromone is oleic acid.

What happens if a perfectly
healthy bee is dabbed with a

drop of oleic acid?

Then, no matter how
hearty it might be,

it's carried,
kicking and screaming,

out of the hive by
oblivious pallbearers.

Do the bees understand the
danger of infection from corpses

decomposing in the hive?

Are they aware of the
connection between
death and oleic acid?

Do they have any
idea what death is?

Do we?

In the tens of millions
of years of collective bee

experience, there's never been
a way that a bee could give

off oleic acid
other than by dying.

So, for bees,
there's no ambiguity here.

Scent of oleic acid
always means dead bee.

There's been no reason for
evolution to develop a greater

sense of nuance about it.

Elaborate, contemplative
machinery is unnecessary to

assess the situation.

Bee perceptions are
adequate for bee needs.

Something similar
is true for moths.

This poor guy has no
idea what the problem is.

There have been moths
for 190 million years,

and clear glass windows
for only about 1,000.

No wonder there isn't
a voice in the moth's
brain that tells it:

if you keep
bumping into something,

even if you can't see it, you
should try to fly around it.

Until very recently on
nature's time scale,

there were no penalties
for moths without any
such inner voice.

Moths evolved in a world
without glass windows.

What then are we to
conclude when we find similar,

very simple behavioral
programs unsupervised by any

apparent central
executive control in so-called

"higher animals"?

When a goose egg
rolls out of the nest,

does the mother goose who
has been incubating her eggs

for weeks understand the
importance of retrieving one
that has rolled away?

Can she tell if
one is missing?

In fact, she will
retrieve almost anything
placed near the nest.

Including ping pong
balls and beer bottles.

The value of this behavior
for goose genes is clear.

She understands something,
but by our standards,

not very much.

Does a beetle
have any emotions?

Any consciousness?

Or is it only a subtle
robot made of organic matter?

A carbon-based automaton
packed with sensors and
actuators,

programs and subroutines,
all ultimately manufactured

according to its
DNA instructions?

We might be willing to grant
the proposition that insects

or even geese are
mindless machines.

But what about us?

What, if anything, do
the other animals think?

What might they have
to say to us if we
could only communicate?

When we observe
them carefully,

don't we find evidence of
spontaneous decision-making?

When we consider the genetic
kinship of all life on Earth,

is it plausible that humans
have immortal souls and all

other animals do not?

In nature, the goose's egg
retrieval program is adequate.

But when the goslings hatch,
and especially just before

they're ready to
leave the nest,

the mother is delicately
attuned to the nuances of

their sounds,
looks and smells.

She has learned
about her chicks.

Now she knows her own very
well and would not confuse

them with an alien object, or
even someone else's goslings,

however similar they may
seem to a human observer.

Consider our friend
the beetle again.

It can see, walk,
run, smell, taste,

fly, mate, eat,
excrete and lay eggs.

It has internal programs for
accomplishing these functions

contained in a brain with a
mass of only a milligram,

and specialized,

dedicated organs for
carrying the programs out.

But is that all?

Is there anyone in charge?

Anyone inside?

Anyone controlling
all these functions?

And what do we mean,
by "anyone"?

Or is the beetle just
the sum of its functions
and nothing else,

with no executive authority,
no insect soul?

A stowaway.

See how it's
triangulating on me,

trying to get a
sense of this immense,

looming three-dimensional
monster before it?

The fly strides along,
unconcernedly,

until you lift a
rolled newspaper and
it quickly buzzes off.

We know this behavior is
wired into the fly's neurons.

(buzz)

Some scientists get
nervous if you ask about the

consciousness of a housefly.

On the inside,
within its tiny brain,

does it have no
perception of making choices?

No awareness of
its own existence?

Not a milligram's worth
of self-consciousness?

Not a hint of
hope for the future?

Not even a little satisfaction
at a day's work well done?

If its brain is one
millionth the mass of ours,

shall we deny it one
millionth of our feelings

and our thoughts?

And if, after carefully
weighing such matters,

we insist it is
still only a robot,

how sure are we that
this judgment doesn't
apply to us as well?

What is distinctly human?

Is there anything
that's ours alone?

TYSON: Would our imaginary
extraterrestrial observer

think that there's anything we
do that distinguishes us from

every other
living thing on Earth?

Something that all
or almost all of us,

of every culture
throughout history,

have done and still do?

Something that no
other animal does?

Plato was one of the
earliest commentators to define

what is human.

He declared, "Man is
a featherless biped."

When news of
Plato's definition reached
the philosopher Diogenes,

he brought a plucked
chicken to Plato's academy,

asking the
assembled scholars
to salute Plato's man.

(laughter)

Plato's protégé, Aristotle,

took another crack at it.

He said, "Man is
a social animal.

Man is a political animal."

But ants,

bees and termites

have much better
organized and much more stable
social structures than we have.

The 16th century
French philosopher
Michel de Montaigne wrote,

"As to fidelity,
there is no animal in the
world so treacherous as man."

But he never dated a firefly.

You know how fireflies blink
on and off to attract a female?

Well, some males sabotage
their fellow fireflies come-on

by adding their own blinks.

It's like hacking a friend's
romantic message to his

girlfriend and
turning it into an insult.

The female gets turned off
and the saboteur now has his

chance with her.

Man, that's cold.

Adam Smith, the 18th
century Scottish philosopher,

wrote in his classic
justification of free

enterprise capitalism that
the propensity to barter,

to exchange one
thing for another,

is to be found in no
other race of animals.

Is this true?

Chimpanzees are fond
of trade and understand
the idea very well.

Food for sex, a
back rub for sex,

betrayal of the
leader for sex,

"spare my baby's life"
for sex.

Virtually anything for sex.

Okay, but we're the only
species that makes art, right?

Except this work of art
was created by a bowerbird.

As was this one.

And this one.

We're the only species that
parents their young through

adolescence into adulthood.

Wrong again.

The elephants parent at
least as long as we do.

All right, well, we're the
only species that enslaves and

exploits other animals,
keeping them in captivity.

Tell that to this
poor cockroach
of the African savanna.

An emerald wasp is stalking
it to drug and enslave

it in its basement.

The wasp administers a venom
which robs the cockroach of

its will to escape.

Turn on the lights,
and this is one roach that

won't scurry away.

Now the wasp drags
the roach to her lair,

depositing a single egg
on the roach's body...

before boarding up the entrance
with rocks and pieces of wood.

The idea is to keep the roach
alive as long as possible so

that its organs
will remain fresh.

The wasp's offspring will
bore into the roach's body and

feast upon it.

When it's full grown,

it will tunnel out
of the roach's grave.

Yeah, but what about
using tools, technology?

Kissing?

♪ ♪

Could it be that after all,

our species' only
real distinction is our
neurotic need to feel special?

Remember this place?

It's the memorial to
the broken branches
of the tree of life.

It's mostly filled with the
casualties of environmental

catastrophe and competition
that happened long before
we ever got here,

but there is a corridor
that we built ourselves.

What lies beyond are all
those species we ourselves

have rendered extinct.

Could there be some connection
to that widespread delusion of

our separateness from
the rest of nature?

A sharp distinction
between humans and animals is

essential if we are to
bend them to our will,

make them work
for us, wear them,

eat them, experiment on them,
wipe them out entirely without

any disquieting
tinges of guilt or regret.

(thunder)

But we all know that this
carelessness is starting to

catch up with us.

Are we automata, robots,
our destiny written in our

DNA with no
possibility of escape?

Is DNA destiny?

And if it is, does it have the
power to write epic tales of
heroism and saintliness?

♪ ♪

TYSON: Okay, just
for argument's sake,

suppose we're nothing
more than the sum total

of our genetic inheritance.

That's not as
bad as it sounds.

There are passages in
our DNA that are every bit

as heroic as anything ever
written in any epic saga.

(growl)

The mother is stotting,
deliberately putting her own

life in danger to alert the
herd and buy time for them...

so that her offspring and the
rest of the herd can get away.

If this isn't
heroism, what is?

And yet, this act of valor
is encoded in the Thomson's
gazelle's programming.

Does that make it
any less brave?

She risks being eaten in
order to save her kin.

And that's the key.

Kin selection is that genetic
impulse for self-sacrifice

prevalent throughout
the kingdoms of life, even us.

Skeptical?

Then do this thought
experiment with me.

Imagine trying to
sleep soundly at night,

knowing that your
children are starving,

homeless or gravely ill.

For almost all of us,
this would be unthinkable,

but 16,000 children die each
day of easily preventable

hunger, neglect, or disease.

Children continue to
die as we sleep well
and watch this show.

They're far away.

They're not
directly related to us.

Now tell me you don't
believe in the reality

of kin selection.

We will die to protect
the carriers of our DNA and

turn away from the
suffering of those who don't.

Kin selection can inspire
us to die saving a brother,

but it's also the drive
exploited by the demagogue

and the supremacist.

The "us" against "them."

Another thought experiment:

Imagine you're making
the first approach to a

newly discovered planet.

You've used various techniques
to ascertain that this world

supports an astonishing
variety of life-forms.

You want to make contact, but
not with their version of a

scorpion, cobra, or
great white shark.

You want to find
the life-form that's
most likely to respond gently,

with empathy and intelligence.

These macaque monkeys
are members of what might

be the most
compassionate species on earth.

This was demonstrated in a
ghastly series of experiments

conducted in the 1960s.

15 macaques were fed only if
they were willing to pull a

chain and electrically shock
an unrelated macaque whose

agony was in plain view
through a one-way mirror.

If they refused to
shock another macaque,
they starved.

After learning the ropes,

the monkeys frequently
refused to pull the chain.

In one experiment, only a
small percentage would do so,

while more than two-thirds
preferred to go hungry.

One macaque went without
food for nearly two weeks

rather than hurt its fellows.

Here's the part
that really gets me.

Macaques who had themselves
been shocked in previous

experiments were even less
willing to pull the chain.

The relative social status
or gender of the macaques had

little bearing on their
reluctance to hurt others.

These experiments permit us
to glimpse in non-humans a

saintly willingness
to make sacrifices in
order to save others,

even those
who are not close kin.

The heartless selfishness
of the rabies virus,

and the transcendent
empathy of the macaques,

are the extreme
ends of a continuum,

one that we,
ourselves, are on.

It was the evolution of
successively larger brains

through the generations of
our ancestors that transformed

human childbirth into an
excruciating experience.

(speaking in native language)

TYSON: Feeling,
in mammals at least,

is mainly controlled by lower,

more ancient parts
of the brain...

And thinking, by the higher,

more recently
evolved outer layers.

A rudimentary ability to
think was superimposed on

the preexisting
programmed behaviors.

This is the evolutionary
baggage we carry with us into

the schoolyard,
into the marriage,

into the voting booth,
into the lynch mob,

and onto the battlefield.

So, what does that
tell us about our future?

Will it be nothing more than
a series of dreary repetitions,

with no escape
for our children?

I know a story
that gives me hope.

It's the saga of a life
that means we can change.

From this distance in time,

it's hard to know
how much of it is true.

It happened a couple
of thousand years ago,

which is a long time to us,

but only about five seconds
ago on the Cosmic Calendar.

The Cosmic Calendar

compresses all of
time into a single year.

I know no better way of
wrapping our heads around the

fact that we are
still very young,

very new to the universe.

January first is the big bang,

and midnight on December 31
on our cosmic year is this
very second.

All of cosmic evolution,
nearly 14 billion years,

compressed into a
single earth year.

Only five Cosmic
Calendar seconds ago,

which represents
about 2,200 years,

much of the world was in
the grip of absolute rulers.

Their armies rampaged
across the planet, bringing

torture, rape, murder,

and mass enslavement
wherever they went.

A young man came
out of an obscure
backwater called Macedonia and,

in less than a decade,

carved out an empire that
stretched from the Adriatic to

beyond the
Indus river in India.

Along the way,
Alexander the Great crushed

the implacable Persian army.

And at about the same time,

King Chandragupta conquered
all of northern India.

His son, Bindusara, assumed
the throne after his death.

As Bindusara's own
death approached,

he intended to bequeath
his empire to a favored heir.

And legend has it
that another son,

one who had been
rejected by Bindusara,

was so ruthless in his quest
for power that he murdered

every one of his
99 half-brothers.

(screaming)

Dressed in the finery
that only an emperor
was entitled to wear,

the hated son stood
before his dying father
and declared contemptuously,

"I am your successor now!"

This was Ashoka...

And he was just getting started.

TYSON:
In the 2nd century BCE,
the Indian emperor Ashoka

initiated a reign of terror
known for its new heights of
sadism and cruelty.

When Ashoka's ministers balked
at his command to cut down all

the fruit trees
surrounding his palace,

Ashoka said, "Fine, we'll
cut off your heads instead."

(screaming)

His fiendishness
knew no bounds.

Ashoka built a
magnificent palace for
his unsuspecting victims.

They did not know until it was
too late that deep inside the

palace were torture rooms
designed to inflict the five

most painful ways to die.

It came to be known
as Ashoka's Hell.

But that was not
Ashoka's greatest atrocity.

He now set out to complete
the conquest of India that his

grandfather had begun.

The nation of
Kalinga, to the south,

knew no peace could be
made with such a madman.

They courageously stood
their ground as Ashoka's army

besieged the city.

When they could bear no more,

Ashoka sent his
troops in for the kill.

(screaming)

(grunting)

As Ashoka
surveyed his triumph,

there was one who
dared to approach him.

MONK: Mighty king, you,
who are so powerful you can

take hundreds of thousands
of lives at your whim.

Show me how
powerful you really are,

give back but one
life to this dead child.

TYSON: Who was this
fearless beggar who dared

to confront Ashoka
with his crimes?

His exact
identity is lost to us,

but we do know that he
was a disciple of Buddha,

then a little known
philosopher who had lived

almost 200 years before.

Buddha preached nonviolence,

awareness and compassion.

His followers renounced
wealth to wander the earth

spreading Buddha's
teachings by their example.

This monk was one of them.

And with his
courage and wisdom,

he found the heart
in a heartless man.

Ashoka was never the same.

TYSON: He erected this pillar,

one of many, on the
site of his greatest crime.

Engraved on it was one of
the first edicts of Ashoka.

ASHOKA: All are my children.

I desire for my own children
their welfare and happiness,

and this I desire for all.

TYSON: It wasn't that
Ashoka was violating the

laws of kin selection.

It was that his definition
of who was kin to him had

expanded to include everyone.

He banned the rituals
of animal sacrifice and

hunting for sport.

He established veterinary
hospitals throughout India,

and he counselled his citizens
to be kind to animals.

Ashoka saw to it that wells
were dug to bring water to the

towns and villages.

He planted trees and built
shelters along the roads of

India so that the traveler
would always feel welcome and

animals would have
the mercy of shade.

Ashoka signed peace
treaties with the small

neighboring countries that had
once trembled at the mention
of his name.

He would govern India
for another 30 years,

and he used that time to
build schools, universities,

hospitals, even hospices.

He introduced the education
of women and saw no reason why

they could not be
ordained as monks.

He instituted free health
care for all and made sure

that the medicines of the time
were available to everyone.

He decreed that all
religions be honored equally.

He ordered judicial review
of those wrongfully imprisoned

or harshly treated.

The temples and
palaces of Ashoka's reign,

and most of the pillars he
erected throughout India,

were destroyed by generations
of religious fanatics,

outraged by what they considered
to be his godlessness.

But despite their best efforts,
his legacy lives on.

Buddhism became one
of the world's most

influential religious
philosophies.

Ashoka's edicts were
carved in stone in Aramaic,

the language of Jesus,

a couple of hundred years
before his birth.

(echoing)

Ashoka sent Buddhist
emissaries to the Middle East

to teach, compassion,
mercy, humility,

and the love of peace.

Hear that?

This is one of the few
temples of Ashoka that
survived the vandals,

a cave in the
hills of Barabar in India.

It's famous for its echo.

The sound waves of my voice
ricochet off the walls until

they're completely absorbed
by the surfaces of objects,

and there's
nothing left at all.

But Ashoka's
dream is different.

Its echo grows louder
and louder with time.

(baby crying)

Who are we?

You tell me.

Captioned by Cotter
Captioning Services.