All language subtitles for Earth.Making.Of.A.Planet.2011.eng

The Earth...

as far as we know

it's the only home
to life in the universe.

So what makes our
planet so special?

To find answers, we must
travel back in time.

See the first humans
walk the Earth.

Ride each colliding continent.

Face killer dinosaurs.

Dive into oceans full
of bizarre life forms.

Feel the bitter chill
of global ice ages.

And experience the fury
of cosmic missile attacks.

By travelling back in time,

we can piece together
our planet's incredible story.

And discover why all
of this, and all of us,

are here.

The journey starts almost
five billion years ago.

There's no sign of
Earth just yet.

Only the Sun,

a newborn star surrounded by dust.

The Earth hasn't formed yet.

But through time,

gravity pulls the dust
into tiny rocks.

To our surprise,

something as complex as a planet

is made from nothing more
than dust and rocks.

Over millions of years,
gravity pulls these

rocks together to
form the Earth,

one of at least a
hundred planets

circling the sun.

But four and a half
billion years ago,

Earth looks more
like hell than home.

Up close the temperature is over

2,000 degrees Fahrenheit.

There's no air,
just carbon dioxide,

nitrogen and water vapor.

It's so hot and toxic
that if we got any

closer we'd be incinerated and

suffocated in seconds.

This newborn planet is
a boiling ball of liquid rock;

an endless ocean of lava.

A young planet called
Theia is heading

straight for Earth.

The size of Mars, it
travels nearly 10 miles

per second, twenty
times faster than a

bullet.

The intruder's gravity
distorts the Earth's surface.

The blast wave races
around the planet.

It's as though both young
planets turn to liquid,

trillions of tons of debris
blast out into space.

But over the course
of a thousand years,

gravity turns the
rubble into a ring of

red hot dust and rock
that circles the Earth.

From this ring, a ball forms,

over two thousand miles wide.

It's the birth of our moon.

But it's much closer
than the moon today,

just 14,000 miles away
instead of a quarter of

a million miles.

The sun rises over
a cooling Earth.

And sets just three hours later.

The Earth is spinning
so fast that an entire

day lasts six hours.

The days may pass
quickly but the Earth

changes slowly.

To understand the
making of our planet we

need to fast foard
through millions of years.

3.9 billion years ago,

a hail of meteors
attack the Earth.

It's debris left over
from the solar system's

formation.

Inside the meteors are
crystals that look like

grains of salt.

And inside the crystals
are minute droplets of

water.

These deadly missiles
could contain the vital

ingredient for life on Earth.

Only a small amount of
water exists inside

each meteorite, but as
they bombard the Earth

for over 20 million years,

pools of water grow.

The Earth's core remains molten,

but its surface has
cooled enough to form a

crust.

The air is around 170 degrees.

In the future, there's
a chance we could

swallow this very water.

Every sip, every puddle,

every drop of water
in every ocean,

is billions of years old.

And it may have
travelled millions of

miles to reach us,
carried inside a

meteor.

The Earth looks more familiar,

but it's still a
dangerous place.

Winds are faster than
the most destructive

hurricanes today.

It's a mega storm,
whipped up by the

planet's rapid rotation.

The moon is so close to
Earth that its gravity

is overwhelmed,
creating huge tides

that race across the
planet's surface.

But over time, the
moon moves away,

the waves calm down
and the planet spins slower.

700 million years after
the planet's birth,

life-giving water
covers its surface.

And scattered
throughout are tiny

islands.

They seem to have
appeared from nowhere.

So how did they get here?

Molten rock bursts
through the Earth's

crust and rises up
through the ocean.

Over time the lava cools,

forming a volcanic island.

In the future, these
islands will join

together to form the
first continents.

Earth now has water and land.

It's beginning to look like
the planet we call home.

But the atmosphere is
still toxic and the

temperature is scorching.

Life here is impossible.

Since the planet's formation,

meteors have been
pummeling Earth.

But now, 3.8
billion years ago,

the assault enters a
violent new phase.

Something's disturbed
the orbits of these

meteorites.

In addition to water,
the meteors carry

something else.

As they dissolve, the
meteorites release

minerals.

Carbon and primitive
proteins made of amino

acids are transported
from outer space to the

bottom of the ocean.

Thousands of feet below
the waves, it is dark,

and close to freezing.

But a dramatic illusion
is taking shape.

Underwater chimneys,
spewing hot liquid.

Seawater seeps down
into the Earth through

cracks in the crust,
collecting minerals and

gases along the way.

This potent mixture is
released back out into

the ocean, building
these towers.

Combined with the
minerals and chemicals

from the meteorites,
the water becom a

chemical soup.

It's impossible to
know how or when,

but somehow these
chemicals come together

to create life.

The water is now
full of microscopic

organisms.

These single-celled
bacteria are the

earliest forms of life on Earth.

This is a defining
moment in the making of

the planet.

Microscopic life is underway.

For hundreds of
millions of years

nothing changes.

The only life is
single-celled bacteria.

To find more complex life,

we need to fast forward
to 3.5 billion years ago,

and a shallow ocean.

These look like rocks,
or even plants,

growing out of the sea bed.

Each mound is a colony
of living bacteria

called a stromatolite.

These bacteria turn
sunlight into food,

a process called photosynthesis.

It uses the power of
sunlight to traform

carbon dioxide and
water into glucose,

a simple form of sugar.

And this magical
transformation releases

a by-product, a
gas called oxygen.

Underwater, the
stromatolites slowly

fill the oceans with oxygen.

The oxygen then turns
traces of iron into

rust, which fall
to the ocean floor,

to form deposits
of iron rich rock.

It's this mineral that
will one day be used to

build bridges, ships,
and skyscrapers.

Above the waves, the
oxygen transforms the

atmosphere.

These stromatolites
are creating the most

important element
for life on earth.

Without them, virtually
every living thing

wouldn't exist.

Over the next two
billion years oxygen

levels continue to rise,

and as the planet's spin slows,

the days get longer,
lasting at least 16 hours.

3 billion years after
the planet's birth,

there's still no complex life,

no plants, no
dinosaurs, no humans.

But the Earth has
something unlike any

other planet in
this solar system,

a force with the power
to change everything.

One and a half billion

years ago, the Earth is
a beautiful blue ball,

dotted with volcanic islands.

Over millions of years,
a mysterious force

rearranges these islands.

Hidden beneath the ocean,

the Earth's crust
breaks into vast

plates.

But even deeper, the
Earth's core is so hot

that it generates
movement in the rock

beneath the crust.

These movements push
and pull the plates

around the globe,
carrying the oceans and

islands with them.

Millions of years race by,

our planet is alive,
and changing.

Over 400 million years
a vast new super

continent takes shape.

It's called Rodinia.

In the shallow waters
surrounding Rodinia,

stromatolites work
their magic for more

than two billion years,
pumping oxygen into the

atmosphere.

The temperature is 85 degrees.

And the days are 18 hours long.

But this planet looks
more like Mars than Earth.

To find life, we must
fast forward through time.

Washington State: 750
million years ago.

A force deep inside the
planet rips the crust

to pieces.

It's as though the
world is breaking

apart.

And there's only one
force powerful enough

to do this, heat.

It escapes from the
Earth's molten core,

stretching and
weakening the crust.

Inch by inch, year by year,

the great super-continent is

splitting in two.

The intense geological
activity spawns a mass

of volcanoes.

They pump carbon
dioxide into the

atmosphere.

The carbon dioxide
mixes with water,

and creates acid rain.

When the continent tore apart,

many rocks were exposed.

These rocks absorb
the acid rain,

including its carbon dioxide.

Vast quantities of CO 2
are absorbed out of the

atmosphere.

Now, there's not enough
carbon dioxide in the

air to trap the sun's
heat around the planet.

In just a few thousand years,

the temperature
plummets to around

minus 60 degrees.

This frozen wasteland
is Southern Australia,

650 million years ago.

It's the start of what
some scientists call

Snowball Earth, a
period they believe to

be the longest, coldest
ice age ever to grip

the planet.

A vast wall of ice
looms thousands of feet

high.

And it's unstoppable.

The more ice there is
the more sunlight it

reflects away from the planet,

and the faster the ice spreads.

Nearby is a second ice
sheet just as high.

The two sheets spread
away from the poles,

toward each other to
meet at the Equator.

Now an ice sheet up to 10,000

feet thick covers
the entire planet.

Earth first began as a
molten ball of fire,

now it's a frozen ball of ice.

Virtually all the sun's
light, and warmth,

reflects back into space.

And it seems as though nothing,

not even the Sun can
rescue the planet now.

650 million years ago,

ice entombs the planet.

For 15 million years,
the Earth is a vast

frozen snowball.

But it can't last forever;

something must release
the Earth from this

frozen prison.

And when it does, who
knows whether life has

survived beneath the ice.

The surface is frozen
but the core is still

hotter than the sun's surface.

Volcanoes have been
erupting since the

world began to freeze.

But up until now even
their heat and power

made no impact on the ice.

Volcanoes pump out
billions of tons of

carbon dioxide.

Before the big freeze,
the Earth's rocks

absorbed most of the CO2.

But now, with the rocks
smothered in ice,

there's nothing to
absorb the gas.

So it fills the atmosphere.

Like a blanket, it
traps the sun's warmth

around the planet, allowing the

temperatures to rise.

Now, after 15 million years,

the ice begins to melt.

It's thought that
during Snowball Earth

the ice pushed the crust down.

But now, as it melts,
the crust bounces up,

creating fissures
and weak spots,

and more volcanoes.

The volcanoes release
more carbon dioxide and

push the temperature
up even higher.

The melt gathers momentum.

And oxygen levels rise.

Through a series of
chemical reactions the

ice has created oxygen.

While the planet was frozen,

the Sun's ultraviolet
rays reacted with water

molecules in the ice,
to produce hydrogen

peroxide, a chemical
rich in oxygen.

Now, as the ice melts,
the hydrogen peroxide

breaks down and releases massive

amounts of oxygen.

The Earth is waking
up, and it's a very

different place.

600 million years ago,
the atmosphere is

warmer, like a summer day.

And the days are
about 22 hours long.

Add all this water and
it's the perfect recipe

for life.

Before Snowball Earth,
primitive bacteria

emerged in the oceans.

But surely they
couldn't have survived

an ice age 75 times
longer than the entire

span of human history.

If something has survived,

then life may be found
where it was last seen,

in the oceans.

Now, 540 million years ago,

in an ocean full of oxygen,

those primitive
bacteria have evolved.

A handful must have
clung on through the

big freeze.

There are plants
scattered on the sea

floor.

And something else.

What looks like an
armored slug takes up

residence.

It's called Wiwaxia,
a new generation of

complex multi-celled organisms.

The Earth enters one
of the most dynamic

periods in its history,
the Cambrian explosion.

Increased oxygen levels
allow creatures to grow

larger and develop
bony skeletons.

There are worms, sponges,

and these trilobites:
distant relatives of

insects, lobsters,
even scorpions.

Life in the oceans blossoms.

From microscopic
bacteria, to monsters.

This is Anomalocaris.

Nearly two feet long,
it has large eyes,

razor sharp teeth
and grasping limbs.

All it has to do,
is take its pick.

The trilobite can't
right itself,

its soft belly is exposed.

Also found in the sea is Pikaia.

Only an inch and a half long,

they may be the first
organism with a spine.

Over millions of years,
this simple structure

will evolve into the
spine that keeps us

standing.

Expecting to find life in ruins,

the oceans are in
fact full of life.

Where trilobites
scavenge and monsters

prowl.

And where creatures
begin to take on

familiar forms.

Beneath the waves there
are already tens of

thousands of plant
and animal species.

The advance of life
seems unstoppable.

460 million years ago,

the plates have
been moving, again.

A new continent now
exists, Gondwana.

It's 90 degrees and
oxygen levels are close

to what they are today.

The land should be
covered with plants and

crawling with creatures.

But there's not much here,

besides a few patches of algae.

There's only one
explanation, the Sun.

It blasts the surface
with deadly radiation,

so the complex life in
the ocean doesn't stand

a chance on land.

But 30 miles up, where
the rays enter the

Earth's atmosphere,
something is happening.

When oxygen meets
the sun's radiation,

it turns into
another kind of gas,

call ozone.

This gas forms a
blanket around the

planet and absorbs
the lethal radiation.

Over 120 million years,
the ozone layer gets

thicker and prevents
more and more radiation

from reaching the
Earth's surface.

Without this layer,
life on land simply

wouldn't exist.

Now, shielded from radiation,

life takes off.

Small mossy lumps are
the first land plants.

They pump out even more oxygen.

Levels soar.

375 million years ago,
a new species lives in

the water, swimming.

It's a strange fish
called a Tiktaalik.

It uses its neck to
raise itself up.

And its fins function as legs,

allowing it to move
out of the water.

This is one of the most
important moments in

the making of our planet.

Over 15 million years,
creatures like these

evolve.

They grow stronger
limbs and spend more

time out of the water,
where plant life is

exploding.

Until, 360 million years ago,

their relatives,
called tetrapods,

make the land their home.

From tetrapods, four
legged vertebrates

evolve into dinosaurs, birds,

mammals and eventually humans.

There are mosses and
ferns everywhere,

some at least a
hundred feet tall.

A seed is carried by the wind.

Until now,

plants reproduced using spores,

single-celled particles
that need plenty of

water to grow.

But this seed is
miles from water.

This embryonic plant
has its own food and

water supply.

Unlike a spore, this
seed can survive far

from water for
months, even years.

The humble seed spreads
life across the planet.

And each tree and plant
pumps out even more

oxygen.

It's an environment
very much like today.

The planet has come a long way,

from a lump of burning
rock and dust,

to a blue and green
world bursting with

life.

There are now fish,
plants, and this,

the dragonfly.

It's called Meganeura.

This insect is the
size of an eagle.

What were once legs
have evolved into

wings, extending the
dragonfly's hunting

territory over a vast area.

There are also millipedes,

and spiders down there.

These creatures,
called arthropod,

were among the first
to set foot on land

hundreds of millions
of years ago.

They look almost
identical to the bugs

that invade our homes today.

Except for one big difference.

Like the Meganeura,
they're monsters.

It's a world full of giants,

where millipedes
are 6 feet long,

andcorpions are
the size of wolves.

This is because the
oxygen level is much

higher than it is today,

which allows their
respiratory systems to

be more efficient,
fueling thier bodies to

grow larger.

So far, animals have
been laying their eggs

in the water.

But a lizard-like creature,

called the hylonomus,
prefers land.

Its eggs contain all
the water and nutrients

that the developing fetus needs.

The babies grow in their own

self-contained pond.

The egg is a major evolutionary

breakthrough.

Allowing animals to
leave the water behind,

and conquer land.

This baby hylonomus
leads the advance,

as a new creature, the reptile.

Inevitably, with
life, comes death.

Dead plant matter
builds up and decays

into dense soggy layers.

Over hundreds of
millions of years,

rocks cover these layers.

And heat from the
Earth's core and

pressure from the
overlying rocks

transform these layers
into seams of coal.

Each lump of coal
burned today is made of

plants that died 300
million years ago.

Amidst the decay,
hidden from sight,

life is stirring.

Soon seeds will germinate,

plants will grow, and
this wasteland will

live again.

Life seems to have
conquered the planet.

But will it last?

A herd of creatures graze

the Siberian plains,
and they are big.

Evolution takes a
huge leap forward,

small lizards are
now giant reptiles.

These scutosaurs are
distant relatives of

turtles.

If these plant eaters
look this tough,

the carnivores must
be seriously mean.

Like this gorgonopsid.

A perfectly engineered
pre-historic killing

machine.

The gorgonopsid's sabre-teeth
wound the scutosaur.

The predator watches,

as its prey grows
weak from blood loss.

But before it can
make its final move,

something strange happens.

The ground gets hot.

Enormous pressure builds
beneath the surface,

and lava spews into the air.

But the lava isn't from
one single volcano,

the entire landscape
is erupting.

It's a flood basalt eruption.

A massive plume of
mantle rises up from

deep inside the Earth,
and pushes molten rock

out through fissures
in the Earth's crust.

The lush paradise is
now a lifeless hell.

The scutosaurs and the
gorgonopsids are dead.

They're the first
casualties in the

greatest mass
extinction the world

has ever seen, the
Permian Extinction.

On the other side of
the continent Gondwana,

nothing's changed, yet.

It appears to be snowing,

but the temperature
is about 70 degrees.

It's actually ash,
fallout from the

eruptions some
10,000 miles away.

The ash burns and
suffocates the animals,

killing them around the world.

Sulphur dioxide from
the eruptions fills the

atmosphere.

As it rains, the gas
turns to sulphuric

acid, and burns
everything it falls on.

What was a local
disaster has now turned

global.

The Siberian eruptions
increase the Earth's

carbon dioxide levels.

The atmosphere gets hotter.

Water evaporates.

And vegetation dies.

Around the world, life
on land is being wiped out.

And life in the oceans,

has also been compromised.

The waters turn pink.

Plants, trilobites, and
predators, disappear.

The new, hotter
atmosphere heated the

oceans and stripped
them of oxygen.

Now, this pink algae
is one of the few life

forms that can survive
in the stagnant water.

The Siberian eruptions
transform the entire

planet, nothing, not
even the deepest ocean

floor, is beyond their reach.

Bubbles of methane gas
escape from beneath the

sea bed.

Methane is a greenhouse gas,

at least twenty times
deadlier than carbon dioxide.

Until now, the gas
has been frozen.

But as the sea
temperature rises,

it begins to melt.

Released into the atmosphere,

this powerful gas
pushes up temperatures

even further.

It's now almost 105 degrees,

11 degrees hotter than
before the Siberian

eruptions.

Creatures that survive
the initial destruction

now face a new and
deadly environment.

Few will live.

It's been five hundred
thousand years since

the eruptions first began,

And all this time, the
lava's been pouring out.

By now, it covers an
area the size of the

United States with a
layer of molten rock

nearly 4 miles deep.

95 per cent of the
species are gone.

A few survive by eating
anything they can find

and living in
burrows underground.

But everything else, is dead.

250 million years ago,
the Earth reverts back

to an almost lifeless planet.

But that's about
to change, again.

It's been fifty million

years since virtually
all life on Earth was

wiped out.

And the planet has
been transformed.

It's now 200 million years ago,

and just one
supercontinent, Pangea,

stretches from pole to pole.

After the trauma of
the mass extinction,

the planet heals.

Temperatures stabilize;
the acid rain

neutralizes and
vegetation returns.

With 95 per cent of all
life on Earth wiped

out, the field opens
for a new species to

emerge.

One that will dominate
the planet like no

other.

The dinosaurs.

These are called Ammosaurs.

Like all dinos, they
evolved from the

reptiles that survived
the Permian Extinction.

At 15 feet tall, their
size makes them slow,

and vulnerable.

Nearby is the dilophosaurus.

It's small,

and fast.

The ammosaurus is too
big a meal for one

dilophosaurus.

But not for two.

The dinosaurs have
repopulated the Earth.

But no species can
tame this restless,

volatile planet.

The earth's crust is thinning.

It's releasing lava
and shaking with

earthquakes, as if
being stretched by some

unseen force.

It's also happening
near what will become

North America's
eastern seaboard.

The Earth's plates are
on the move again.

190 million years ago, the great

super-continent of
Pangea tears apart.

A vast slab of land breaks away,

creating a chasm.

It fills with a new
ocean called the Tethys

over what will one day
be the Middle East.

Currents push nutrients up into

the coastal waters.

And the nutrients attract fish,

in the millions.

But again, with so much
life, also comes death.

Dead fish and plankton
carpet the ocean floor.

Over the next 10 million years,

layers of rock
will bury and heat

the dead creatures.

Ancient fish and

plankton will become oil.

Every gallon of gas in our cars,

every piece of plastic
on the planet,

the paint on our walls,
the carpet under our

feet, even the
soap we wash with,

almost all originated in this way.

180 million years ago,
the North American plate

is still moving away from
the European and Asian plate.

It's shifting about
one inch each year,

the same speed at which
our fingernails grow.

But fast forward 35
million years and a new

ocean forms, as well
as new continents.

The United States
breaks away from Africa.

The world as we
know it takes shape.

The chasm between the
two continents fills,

creating the Atlantic Ocean.

And in the middle,
lies a volcano.

Like before, currents
deep beneath the

Earth's crust move
the plates again.

The entire sea floor
tears in two and is

pushed up into a ridge of

mountains and volcanoes.

It grows higher
than the Himalayas,

and longer than the Rockies.

The water here is hot,
as molten lava forces

its way out from deep
inside the earth.

As the lava cools, it
creates a new range of

volcanic mountains,
and a new ocean floor.

Pangea breaks apart,
and our world

rearranges again.

It's this geological
activity that makes the

Earth restless,
creative and unique.

And every time the
planet reinvents

itself, its inhabitants
adapt and evolve.

Like the ichthyosaurs.

Their reptile ancestors
lived on land,

but as the planet changed,

so did these animals.

They grew fins and
moved into the newly

formed Atlantic Ocean.

This one is 20 feet long,

and can travel at a
quick 25 miles an hour.

It's the ocean's
fastest creature and

most efficient predator.

It rules the oceans
for 50 million years.

But now, there's
a new contender.

The pliosaur.

Longer than a bus, and
as heavy as a truck,

its jaws are eight
times more powerful

than a great white sharks',

with teeth 12 inches long.

The Earth, and its inhabitants,

have changed beyond recognition.

This was once solid ground,

now it's the Atlantic Ocean.

The very spot where
ammosaurs grazed and

dilophosaurs stalked their prey.

The dinosaurs' world
may be different,

but they're as dominant as ever.

They appear invincible.

They're one of the planet's most

successful species.

They've survived
volcanic eruptions,

earthquakes, and entire
continents splitting

apart, The dinosaurs
have thrived for 165

million years.

A number of mammals
have also survived,

like this shrew-like animal.

They're prey to the dinosaurs.

So they live in trees
or underground,

and venture out only at night.

Mammals pose no threat
to the dinosaurs.

Nothing on Earth
can challenge their

dominance.

Nothing, on Earth.

A large piece of space rock
heads toward Earth.

This asteroid is at
least 6 miles across,

and travelling over
40,000 miles an hour.

It's bigger than Mount Everest,

and heads straight for
the Gulf of Mexico.

It travels so fast that
its impact would be

missed in a blink of an eye.

A split second changes
the world forever.

At impact, the
asteroid's back edge

stands at 35,000 feet.

It strikes with such
immense force that it

destroys everything it hits.

The asteroid itself
instantly vaporizes,

unleashing the
energy of millions

of nuclear weapons.

Nowhere is safe,

with debris flying everywhere.

Debris as big as
entire city blocks

circle the Earth.

The blastwave races out
from the impact zone

like shrapnel from
an exploding bomb.

Minutes after impact,
hundreds of miles

from where the asteroid struck,

the earth is under attack.

Boulders rain down.

Earthquakes shake the ground.

And tsunamis batter the coasts.

But the onslaught
has only just begun.

The plume of molten
rock and dust spreads

out, and engulfs the planet.

The entire sky acts
like a giant lamp,

heating the Earth's surface to

over 500 degrees.

Vegetation spontaneously ignites.

Even months after the impact,

smoke and ash still block out

the sun's rays.

And with less sunlight,

plants die and the animals starve.

65 million years ago,

the impact has blasted,

stoned and burnt the dinosaurs.

Their 165 million year reign is over.

But the dinosaur's demise brings

opportunity for another species.

A mammal.

By living underground,
mammals have avoided

the heat and fires.

And by eating anything,
they thrive while more

selective eaters die.

They're the unlikely inheritors
of the dinosaurs' crown.

And as one story ends.

Another begins.

With the dinosaurs
out of the way,

our ancestors' may now
have a chance, at life.

The dinosaurs are long dead.

The planet is peaceful.

In this new world,

our mammal ancestors are evolving.

47 million years ago, this lake,

in what will one day be Germany,

is the perfect place to spot them.

Unlike earlier
mammals, its eyes and

brain are bigger.

This is Darwinius Massilae, or Ida.

She looks nothing like humans,

but fossil evidence
today indicates that

these creatures might
evolve into monkeys,

apes, and eventually humans.

Looking back through
47 million years of

evolution might reveal
one of our earliest

known ancestors.

The lake sits on a
volcanic crater.

It belches out noxious gas,

that eventually kills Ida.

The lake preserves her in its

oxygen depleted depths.

One day, when the water
is gone and Ida's

fossil is found, this
primitive primate could

help piece together the
beginning of our own

story, the story of human life.

We're closer to
understanding how

everything we've seen,
from ocean bacteria,

through walking fish
and subterranean

rodents, leads to us.

And to understanding how our

planet was made.

47 million years
ago, the atmosphere

is much like today.

The temperature is 75 degrees.

And a day lasts just under

twenty four hours.

The Earth is now
almost identical to

the planet we call home.

Almost.

The Earth's plates are
on the move again.

India moves north toward Asia.

The Indian and Asian
plates are locked

in a titanic struggle,

and neither plate is winning.

As they buckle, the
ocean floor contorts

upward along a 1,500 mile line.

A vast mountain range rises up

over 27,000 feet.

These are the Himalayas.

And the highest mountain of all,

Mount Everest.

Its summit reaches up into the

Earth's jet stream,
the same altitude

where planes fly.

When the snow on
the peaks melts,

it feeds rivers like
the Ganges, Indus,

Yellow and Yangtze.

The Himalayas are like
a vast water tower.

One day, their rivers
will supply water for

almost half the
world's population.

20 million years ago,
this is our planet,

with every continent,
and every ocean

as we know it.

Except one thing
is still missing,

the human race.

And for humans to evolve,

something needs to change.

Along the African

coast, a great rift opens up.

It stretches nearly 4,000 miles,

with mountains growing
along its edge.

This ape-like creature
may stay in these trees

forever, but its
world is changing.

The growing mountains
act like a wall,

prohibiting moisture
from the Indian Ocean

from passing over the land.

It's getting hotter, and drier.

The lush rainforest
becomes an arid

savannah.

The new hotter climate
changes the creatures'

habitat, forcing them
to search further for

food, soon, they stop
dragging their knuckles

like apes.

And begin to stand,
and walk on two feet.

It's the most important step in

the human story.

This mountain range
could be the reason

humans walk on two feet.

The random movement of
two plates may have

kick-started a chain of
events that leads to

the first humans.

A man and child.

A scene very much like today.

But it's one and a half
million years ago.

They are an early
species of human called

Homo Erectus.

And these are the first
footprints like our

own; civilizations
past and present,

everyone that's ever lived,

the greatest inventions,

the most brilliant ideas.

Human history, in all
its complexity and

splendor, begins here and now.

The climate changes again.

70,000 years ago
sea levels fall.

And the gap between
Africa and Arabia

shrinks to just eight miles.

The Red Sea is now
narrow and shallow

enough for a small
group to cross,

out of Africa.

They're another later
species of human,

called Homo Sapiens.

Scientists believe that
the entire world beyond

Africa was populated
from descendants of

these two hundred individuals.

Over time our ancestors
multiply and spread

out; to India, onto
Asia and into Europe.

But while humans head north,

a giant wall of
ice travels south.

Europe, 40,000 years ago.

Homo sapiens arrive,
only to find a world

that's quickly changing.

It should be the
height of summer,

but it's getting colder.

The plants are frostbitten,

and the rivers are frozen.

Natural changes in
the Earth's orbit,

CO2 levels, and the
flow of warm water

around the planet
conspire to lower the

Earth's temperature.

The Earth, and its inhabitants,

enter an ice age.

Glaciers as high as
skyscrapers creep over

the northern hemisphere
about a foot every day,

Slow, and powerful,
they sculpt the

landscape, gouging out
great depressions.

The planet will never
look the same again.

Now, around twenty
thousand years ago,

they grind to a halt.

Much of the northern
hemisphere is covered

by ice sheets up to one
and a half miles thick.

With trillions of
gallons of water locked

up as ice, sea levels fall.

A strip of land emerges
from the ocean between

Siberia and Alaska.

It's a bridge between
two vast continents,

a gateway that takes
humans from Asia to a

new world, the Americas.

They're the last great
continents to be

colonized, the last
great human migration,

and the first Americans.

Now, 14,000 years
ago, the changes that

triggered the ice age reverse.

As the ice retreats,
it reveals a very

different northern hemisphere.

The huge depressions
that the glaciers

create fill with
water to become North

America's Great Lakes.

6,000 years ago, the
ice retreats back to

the poles, toward the
Arctic and Antarctic.

After a four and a half
billion year journey,

we're, finally home.

This is our world, our time.

The planet's incredible
story helps us

understand how and why
everything around us is

here today.

From the skies above.

To water, the essential
ingredient for life.

To the ground beneath our feet.

And finally life,
a chain of catastrophes

and coincidences, creating a

spectacular result.

Each triumph and
disaster is a step

leading to here,
each and every one of

us, right now.

But the Earth's
story isn't over.

This journey is only
half the story.

A lot more is yet to come.

The Earth will live for
at least another 4.5

billion years.

More wonders, more terrors,

and more strange
creatures lie ahead for

our restless and
creative planet.

The next chapter of Earth's story

is still to be written.