All language subtitles for David.Attenboroughs.Galapagos.S01E01.Origin.2160p.NOW.WEB-DL.DDP5.1.H.265-RAWR_track3_[eng]

In the vastness of the Pacific,
there's a place unlike any other.

Enchanted volcanic islands
that are home to a remarkable

collection of animals and plants.

Here, evolution is proceeding with
spectacular speed.

Black lizards that swim in the ocean

and spit salt from their noses.

Penguins, thousands
of miles from Antarctica.

And an abundance of unique plants.

Some animals are tiny,

and some have only just
been discovered.

This is a place of wonders.

Galapagos.

Islands born of fire,

with inhabitants that have

transformed our understanding
of the whole of life on Earth.

In a lifetime spent making
natural history films,

I've been to many wonderful places

but none more extraordinary than
here, the Galapagos Islands.

These have been called nature's
greatest experiment, for here,

life has evolved in isolation and
produced some extraordinary results.

The extraordinary
creatures of Galapagos astounded

Charles Darwin when he first came
here 200 years ago.

They led him
to formulate his revelatory

theory of evolution by natural
selection.

And now, 200 years later, there
are still mysteries to be solved

and new discoveries to be made.

Teams of scientists are
investigating unexplored regions of

the remote islands and discovering
hitherto unknown animals.

On the peaks of its volcanoes,

inside networks of immense

tunnels within the lava flows

and in its crystal clear waters.

Among a population of giants,

and in the magical world that is
revealed by the microscope.

New technologies are enabling
scientists to investigate

the workings of evolution
in new ways

and producing insights that would
have astonished Darwin himself.

Today, we know a lot
more about these islands.

The discovery of new species,

long-term studies
extending over decades,

have given us new perspectives
not just on this place,

but on the process
of evolution worldwide.

The islands lie 600 miles
from the coast of South America

and straddle the equator.

There are 16 of them,
and a multitude of small islas,

all separated from the rest of the
world by the huge expanse of ocean.

The biggest island is Isabela.

Lying in the centre of the group, it
has a strange seahorse-like shape.

That is because it originated as six
separate volcanoes which

eventually fused into one
great island.

The most remote of them is Alcedo.

Its vast crater is four
miles across.

The huge steep-sided walls,

still smoking with jets of
volcanic gas and steam,

make this one of the most
isolated places in the Galapagos.

And it has become
a sanctuary for one of the islands'

most spectacular inhabitants.

Giant tortoises.

There are thousands of them.

These are the extraordinary
creatures that gave their name

to the islands.

Galapagos in Spanish
means tortoise and here,

in the pit of the volcano Alcedo,
they've assembled in quite

some numbers to wallow in the warm
volcanic mud.

A big one can weigh as much
as a quarter of a ton.

They live for up to 100 years or
more, which makes them

amongst the most long-lived of all
vertebrates. And being reptiles,

they get their energy
by basking in the sun.

But their bodies are
so big that once they are warmed up,

they can carry on browsing
for quite a long time.

The existence of creatures
like these,

so far from the nearest continent,
poses many questions.

How, for example,

did these enormous beasts get to
the islands in the first place?

But perhaps the most extraordinary
thing about the Galapagos

tortoises is that they're not
all the same.

Different islands have
different kinds.

In their heyday there
were 15 species.

They seem to have appeared in an
evolutionary blink of the eye

in this tiny cluster of islands.

And the tortoises are not
alone in this.

Almost every animal and plant
in the islands has a similar story.

The animal colonists began to
change from the moment they arrived,

driven to do so by the harsh
volcanic landscape around them.

There is evidence all around these
islands of their direct

connection with the furnaces
deep in the Earth's crust.

But it wasn't
until recently that we

realised just how close those
connections are, here.

Underneath the section
of the Earth's crust

on which Galapagos sits,
there is something extraordinary.

A gigantic column of super-heated
molten rock rising upwards.

This hot spot is immense.

At least 60 miles across.

It extends downwards for 1800 miles

and connects the islands to the very
centre of the Earth.

This image, based on the very
latest seismological data,

shows the hot
spot from underneath the crust.

This is the source of the islands'
volcanic activity.

It began to build the Galapagos
four million years ago.

A series of islands
emerged from the sea.

Today, there are 16 of them,
all of which are volcanoes.

Most are now extinct and the oldest
are crumbling into the sea.

But the newer islands are still
active and spitting fire.

The youngest is Fernandina.

It rose from the sea
just 500,000 years ago.

And because it's still active,

the lava fields that cover
it are still unweathered.

And here, in this desolate,
barren place, we can see how the

ingredients of a great natural
experiment came together.

Fate placed these islands
in a unique spot on this planet.

They lie plumb on the equator,
with its year-long warmth

and sunshine. But perhaps,
more importantly,

they also lie at the crossroads
between two competing winds.

The southeast trade winds blow
up from South America

and the northeast trades come down

from the Caribbean and
Central America.

These two winds are the lifeblood
of the Galapagos.

They carried the earliest settlers
to the emerging volcanic islands.

Seeds falling from trees
in South and Central America

were blown across
hundreds of miles of ocean.

Most were lost at sea.

Of those few
that reached the islands,

many fell on sterile,
baking-hot rocks,

but just a few were luckier.

This extraordinary species
is related to dandelions.

And it's find a way to grow where
there is neither soil nor rain.

A wind-blown seed arrives
and drops in a crevice in the lava.

Moisture collects
and causes it to germinate.

With its tiny leaves
it manages to collect more moisture

and the infinitesimal
quantities of nutrients

that moisture from the skies
might contain.

Some of these leaves
may look dead...

...and indeed they are.

The plant is deliberately
shedding them.

It's ensuring
that nothing it produces is wasted.

It's creating its own soil.

And, eventually, after 80
to 100 years, it produced this,

scalesia, which seems to grow
straight out of naked rock.

After such tiny beginnings
this extraordinary plant

has gone from strength to strength.

Today, whole forests
of giant dandelions

blanket the higher slopes
of the islands.

But some plants used
a more direct mode of transport,

than a mere gust of wind.

A bird.

The albatross
is the king of long-distance flight.

It spends most of its life
on the wing.

But each year it lands somewhere...

to breed and raise a chick.

The appearance of a new island
in the middle of the ocean

provided albatrosses
with a new nesting site.

And often these huge birds
brought hitchhikers.

Seeds stuck to their feet
and in their feathers.

They may even have given their
hitchhiker's a head start in life

with a nice packet of fertilizer.

So, gradually,
small patches of vegetation

began to appear
on the newly-emerged islands.

The seeds of most trees

are too big to be carried far
by birds or the wind.

But those that habitually
grow along the coast,

can use a different form
of transport.

This is the seed of a mangrove

and when it falls,

it drops into the sea... and floats.

This part of it is green, so it
can make food just like a leaf can.

And the seed can remain at sea
alive for a very long time.

But, eventually,
it may float into an estuary.

And there the water
is brackish and less buoyant.

So, the heavy end of the seed falls

and it hangs in the water,
like this.

And its tip, maybe at low tide,

trails into the mud and sticks.

And the mangrove has planted itself.

These trees are very effective
colonists of newly-formed islands.

The young seedlings
quickly establish themselves.

Their tangled, arching roots
form a grid

which slows down the tidal water
surging through them,

causing it to drop its sediment
as mud.

At low tide, all kinds of creatures

come out
to scavenge among the roots.

And when the tide is high, other
creatures swim in to find shelter.

The waters around the tangled roots

serve as nurseries
for many species of fish.

So plants created habitats

where animals could survive
both in water and out of it.

Some of the very first animals
to reach these islands were spiders.

There are some 150 different known
species of them

in the Galapagos today,

and they travel in a way that
is all their own -

they balloon.

The hatchlings of many species use
specially adapted silk.

A spiderling climbs to
the tip of a leaf or a twig.

There, it produces
a thread of silk from the spinnerets

at the end of its abdomen.

This 3D electron micrograph
shows that this thread is actually

two filaments that are stuck
together.

It's flattened like a blade.

The slightest wind will catch it.

Once a gust is strong enough,

the spiderling lets go with its feet
and is carried up

and away.

Some can float up to an altitude
of several thousand metres.

And up there in the trade winds
millions of years ago,

and doubtless many times since,

some of them made the 600 mile
journey to the Galapagos.

And spiders were not alone,
floating through the skies.

Many different forms of life
were brought

here by the wind from the
South American continent -

seeds, pollen,

viruses, bacteria,

algae and insects.

Insects, of course, are extremely
important in most ecosystems.

They pollinate plants

and they're food for many other
kinds of animals.

The species that reached
here are nearly all the smaller

South American species.

The bigger ones were too heavy to
make the journey.

But one quite large insect did so.

And its arrival started a new
phase in the colonisation

of the Galapagos.

It was a beetle.

Beetles are nature's great
recyclers.

They chew up organic matter
and that helps to create soil.

Beetles have sizable bodies
but also large wings.

That made it possible for one
species to make

a wind-assisted passage to
the Galapagos.

Once here,
these beetles began to change.

Later generations had smaller wings.

In fact, some Galapagos beetles
lost their wings altogether.

Those individuals with smaller wings
were much more likely to stay put.

That is because the big wings that
brought the beetles here can

equally well carry them off again.

Insects and plants that were brought
together in this very

arbitrary way now began to
establish new relationships.

But one, in particular,
had a very far-reaching effect.

Sometimes, surprisingly perhaps,

flying insects arrived in the
Galapagos not by air, but by sea.

Inside this piece of wood,

there is a nest of a little
carpenter bee, whose ancestors

must certainly have arrived
here in that way.

This unimpressive little creature
was to be of great help to

many of the newly-established
plants.

It fed on their nectar
and pollinated them.

Carpenter bees are still the main
pollinators on the islands.

And the plants have adapted
accordingly.

Nearly all the flowers
on the Galapagos

are now either white

or yellow.

Those are the colours
preferred by the carpenter bees,

so there's no point in being
anything else.

So, land plants flourished.

In the sea, there was another factor
that helped the colonists.

Amazingly, it came not from the
nearest land, South America,

but from 8,000 miles away,

across the Pacific in the
other direction, to the West.

From the tropical
rainforests of New Guinea.

Here there are heavy downpours
every day.

The rain washes
nutrients from the forest soil,

down streams into rivers

and finally, into the ocean.

And there, swept up by the currents,

they're carried across the Pacific
to the Galapagos.

They travel not near the surface

but in the depths, by a cold
water current.

It's one of three that
converge on the islands.

Another comes from the Panama Basin.

And yet another
originates near Peru.

This convergence of currents
has had a remarkable

impact on life in the islands.

Scientists, led by marine biologist
Stuart Banks,

are today investigating
their effect.

Well, Galapagos is
unique in the sense that it's

a system in the Tropics, it's lying
right on the equator under

the strong equatorial sun
and these are usually systems

which are considered to be
deserts for productivity.

But Galapagos is different.

There's a unique confluence
of currents and most importantly,

a submarine undercurrent called
the Cromwell current,

and these undercurrents are bringing
micronutrients up into these

sunlit waters.

The Galapagos Islands
in the open Pacific

lie in the path of these
converging currents.

They deflect the cold,

nutrient-laden waters upwards to
mingle with the warm water above.

This mixing creates ideal
conditions for a vast

community of floating
microscopic plants.

Phytoplankton.

Each tiny organism is only a few
microns across

and invisible to the naked eye.

Yet these specks of life underpin
the whole Galapagos ecosystem.

And here the fertilizer
from New Guinea enables them

to hugely increase in both variety
and number.

Scientists have now discovered
that the islands themselves provide

the phytoplankton with something
that is crucial for its growth.

A vital life-enhancing
element -

iron.

Now the undercurrent which hits
the western side of the archipelago,

it's a bit like imagining pointing
a hose against the side of a wall.

It forms filaments that physically
spread around the archipelago

and up into the surface.

And it's thought that it's
the abrasion

and the leaching
against the volcanic platform

of the islands which is bringing
iron up into the surface waters.

So, thanks to that unique situation,

you tend to get these huge
phytoplankton blooms and this

is literally millions of these tiny
organisms coming together.

This extraordinary image,
based on satellite data,

shows how blooms of phytoplankton
grow and shrink over the seasons.

These astronomic numbers
of microscopic plants support

another vast community.

Microscopic animals -

zooplankton.

Here, under the waves,

there is a living world of
extraordinary complexity and beauty.

All these tiny creatures
are dependent on the rich

blooms of the phytoplankton.

Some graze on them.

Others graze on the grazers.

Many equally extraordinary creatures
feed on the rich soup.

From small crustaceans

and juvenile jellyfish,

to the young of many fish.

These tiny animals and plants,
in turn, support shoals of larger

fish that swarm in such numbers
and variety that they make

the Galapagos waters among the most
diverse of all marine ecosystems.

Many extraordinary creatures feed
directly on the plankton itself.

Garden eels are quite small,

some 15cm or so long.

But much bigger fish also
feed on the plankton.

They, in turn, are food for hunters.

Among them, the Galapagos shark,

a relative of the tiger shark.

And scalloped hammerhead sharks,
which today congregate

here in numbers that are unequalled
anywhere else in the world.

Huge schools of females are often
surrounded by an outer

ring of patrolling males.

No one is quite sure what's
happening at these times.

It's probably
part of their mating behaviour.

Many coastal species are unique
to these islands.

This is the red-lipped batfish.

Its lower fins have been
modified to enable it to

prowl across the seafloor.

The Galapagos sea robin
can also walk

and flashes its bright petrol fins
to frighten away predators.

The trumpetfish
has such an elongated body

that it's hard to see, so it's able
to sneak up on its prey.

And there are giants here too.

This is the Mola Mola, the sunfish.

It's huge,

three metres across and addicted to
lying on its side at the surface.

It eats vast quantities
of jellyfish.

And there are not only fish swimming
in these waters, there are mammals.

Sea lions, whose ancestors
originally came from the coasts of
California.

The Galapagos plankton is
so abundant,

it attracts some of the biggest of
all ocean mammals -

humpback whales.

And rivalling them in size,
the biggest of all fish,

the 20-ton whale shark.

Few parts of the world's oceans can
equal these Galapagos

waters for sheer variety
and abundance of marine life.

And this richness in turn has
attracted a great

variety of sea birds.

Many are long-distance travellers.

The islands have become the best
place in hundreds of square

miles of open ocean for many birds
to rest and to breed.

The Nazca Boobies range
across the whole of the Pacific

but this waved albatross lives
nowhere else but here.

The male frigate bird has a pouch of
scarlet skin hanging from his neck.

During the breeding season,

he inflates it to attract a mate
or see off a rival.

There's also another kind of Booby -

the blue-footed.

His spectacular feet are the key
elements in his courtship

display in which
he tries to persuade his mate

that his really are the bluest
feet around.

Boobies are superb fishermen.

Once they spot a shoal, they fly out
to a height of 25 metres

and then they dive into the water at
speeds of 60 miles per hour or more.

Hitting the water with such force
could kill many birds

but boobies have special air sacs in
their heads that cushion the impact.

Cormorants are coastal birds rather
than ocean travellers

so they can only have arrived
in the Galapagos by accident, having

probably been swept out to
sea by a gale.

But they arrived a very long time
ago

and they stayed.

Like cormorants worldwide,

the Galapagos species is
a superb swimmer.

Its legs are powerful paddles.

And the body itself is
beautifully streamlined.

In effect,
the cormorant flies underwater

and it's certainly able to
out-manoeuvre many a fish.

The Galapagos coast is a great
place for a cormorant.

There are plenty of excellent
nesting sites.

And there are no land predators that
might threaten a bird

sitting in such a vulnerable place.

Its ancestors, when they first
arrived, had wings

like any other cormorant.

But with no need to fly,

its wings over generations became
smaller and smaller.

Now, they are mere stumps with
a few tattered feathers.

So now, the bird can't
fly even if it wanted to.

And since it's flightless,

there is no disadvantage in growing
bigger and the Galapagos

cormorant is now heavier than
any of its flying relatives.

With nothing to hassle it and plenty
of fish in the sea alongside,

the cormorants can now concentrate
on caring for their young.

And in fact, some manage to raise
three broods each season.

But there is another permanent
resident here whose history

is even more remarkable.

Its ancestors lived 5,000 miles
away in the Antarctic.

That creature was a penguin.

Penguins are ocean-going swimmers

but a few thousand years
ago some of them

got caught in the cold waters of the
Humboldt current and were carried

northwards up the coast of South
America and out to the Galapagos.

They could hardly have found
anywhere more

different from their polar home

and in response, they changed.

The emperor penguin that lives
near the South Pole stands over

a metre high.

The Galapagos penguin

is now only half as tall.

And that helps
a lot in the Galapagos.

Small animals lose heat much
faster than big ones.

And the penguins have developed
behavioural tricks as well.

Bare feet are easily sunburnt

so they do their best to keep them
covered.

And some parts of the sea
around the islands are quite cool.

The Humboldt current, flowing
up from the Antarctic and washing

around the western parts of the
archipelago, is still quite chilly.

So, most of the penguins
stay in the channel between the two

western-most islands.

And when things get really hot,
they can still cool off with a swim.

They're quick to detect
the slightest

variation in temperature
and move around to find places where

an eddy might have brought
a pleasing chill.

The arrival of penguins must be
the most unlikely

event in the whole story of the
colonisation of the Galapagos.

But the most important

and influential animals had
yet to appear.

Not birds,

but reptiles.

Many million years ago, somewhere in
South or Central America,

a reptile, an iguana,

was grazing close to the
banks of one of the great rivers.

Perhaps it was
feeding on floating vegetation.

Maybe it fell onto such
a raft from a tree.

Patches of floating
vegetation are still swept

out into the estuaries by flash
floods or tropical storms.

Many are quite big,

and easily buoyant enough to support
a metre-long iguana.

And sometimes, they don't break up
but float out to the open ocean.

Who knows how many thousands
of animals of many kinds have been

lost at sea on rafts like these,
dying from thirst and exposure?

But reptiles are very tough.

They can go without food or
water for days, weeks, even months.

No mammal can survive such
hardships as long as they can.

And, at some point in the history
of the Galapagos, the currents

carried an iguana across 600 miles
of ocean to the islands.

No doubt it happened not once
but several times.

And here, the iguanas settled
and multiplied.

Today, there are thousands of them.

So many, and so widely distributed
throughout the islands,

that they are now one of the
Galapagos' most famous inhabitants.

But these are the most
celebrated of all.

The ones that gave the islands
their name -

giant tortoises.

Tortoises can't swim, but
they can float.

And about three million
years ago, one of them,

a large species from the
South American forests,

was carried away perhaps by
a flash flood and swept out to sea.

After weeks, maybe even months,
they eventually landed on an island

and one of them, perhaps a gravid
female, produced eggs.

As time passed, they spread into
other islands in the archipelago.

Giant tortoises had arrived

in the Galapagos.

With this small selection of animals
and plants in place,

nature's great experiment
gathered pace.

Forged by fire,

fuelled by the ocean,

fanned by the winds

and seeded by a very few
and very different species.

A new community was established
here in the Galapagos,

and one with a very small but very
oddly assorted cast of characters.

There were no amphibians.
Because of their porous skin,

they are poisoned by seawater.

There were no mammals
except for a small short-tailed rat.

Flying insects and seeds of plants
had reached here,

brought by the wind.

But fundamentally, this was
a land of birds which flew here

and reptiles which floated here.

And together, they had to make
a living on this bare,

rocky island that was so crucially
different from the well-watered,

luxuriant forests from which
they had come.

In the next programme,
we will discover how this strange,

oddly assorted cast of characters
learned to colonise even the

most hostile parts of the Galapagos
and to live with one another.

And how they changed in the process.

And we venture even
deeper into the islands,

into places where even today,

new species are being discovered.

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