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

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Enchanted volcanic islands
that are home to a remarkable

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collection of animals and plants.

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Here, evolution is proceeding with
spectacular speed.

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Black lizards that swim in the ocean

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and spit salt from their noses.

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Penguins, thousands
of miles from Antarctica.

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And an abundance of unique plants.

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Some animals are tiny,

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and some have only just
been discovered.

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This is a place of wonders.

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Galapagos.

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Islands born of fire,

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with inhabitants that have

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transformed our understanding
of the whole of life on Earth.

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In a lifetime spent making
natural history films,

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I've been to many wonderful places

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but none more extraordinary than
here, the Galapagos Islands.

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

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life has evolved in isolation and
produced some extraordinary results.

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The extraordinary
creatures of Galapagos astounded

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Charles Darwin when he first came
here 200 years ago.

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They led him
to formulate his revelatory

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theory of evolution by natural
selection.

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

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and new discoveries to be made.

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Teams of scientists are
investigating unexplored regions of

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the remote islands and discovering
hitherto unknown animals.

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On the peaks of its volcanoes,

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inside networks of immense

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tunnels within the lava flows

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and in its crystal clear waters.

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Among a population of giants,

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

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New technologies are enabling
scientists to investigate

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the workings of evolution
in new ways

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and producing insights that would
have astonished Darwin himself.

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Today, we know a lot
more about these islands.

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The discovery of new species,

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long-term studies
extending over decades,

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have given us new perspectives
not just on this place,

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but on the process
of evolution worldwide.

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The islands lie 600 miles
from the coast of South America

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and straddle the equator.

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

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

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The biggest island is Isabela.

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

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That is because it originated as six
separate volcanoes which

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eventually fused into one
great island.

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The most remote of them is Alcedo.

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Its vast crater is four
miles across.

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The huge steep-sided walls,

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still smoking with jets of
volcanic gas and steam,

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

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

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most spectacular inhabitants.

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Giant tortoises.

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There are thousands of them.

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These are the extraordinary
creatures that gave their name

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to the islands.

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Galapagos in Spanish
means tortoise and here,

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

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some numbers to wallow in the warm
volcanic mud.

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

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

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

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they get their energy
by basking in the sun.

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

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they can carry on browsing
for quite a long time.

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The existence of creatures
like these,

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so far from the nearest continent,
poses many questions.

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How, for example,

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

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But perhaps the most extraordinary
thing about the Galapagos

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tortoises is that they're not
all the same.

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Different islands have
different kinds.

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In their heyday there
were 15 species.

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

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in this tiny cluster of islands.

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And the tortoises are not
alone in this.

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

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

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

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There is evidence all around these
islands of their direct

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

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But it wasn't
until recently that we

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realised just how close those
connections are, here.

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Underneath the section
of the Earth's crust

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on which Galapagos sits,
there is something extraordinary.

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

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This hot spot is immense.

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At least 60 miles across.

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It extends downwards for 1800 miles

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

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This image, based on the very
latest seismological data,

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shows the hot
spot from underneath the crust.

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This is the source of the islands'
volcanic activity.

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It began to build the Galapagos
four million years ago.

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A series of islands
emerged from the sea.

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

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

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But the newer islands are still
active and spitting fire.

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The youngest is Fernandina.

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

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And because it's still active,

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the lava fields that cover
it are still unweathered.

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

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ingredients of a great natural
experiment came together.

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

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

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and sunshine. But perhaps,
more importantly,

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they also lie at the crossroads
between two competing winds.

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The southeast trade winds blow
up from South America

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and the northeast trades come down

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from the Caribbean and
Central America.

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These two winds are the lifeblood
of the Galapagos.

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They carried the earliest settlers
to the emerging volcanic islands.

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Seeds falling from trees
in South and Central America

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were blown across
hundreds of miles of ocean.

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Most were lost at sea.

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Of those few
that reached the islands,

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many fell on sterile,
baking-hot rocks,

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but just a few were luckier.

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This extraordinary species
is related to dandelions.

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

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

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Moisture collects
and causes it to germinate.

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With its tiny leaves
it manages to collect more moisture

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and the infinitesimal
quantities of nutrients

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that moisture from the skies
might contain.

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Some of these leaves
may look dead...

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...and indeed they are.

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The plant is deliberately
shedding them.

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It's ensuring
that nothing it produces is wasted.

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It's creating its own soil.

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

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

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After such tiny beginnings
this extraordinary plant

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has gone from strength to strength.

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Today, whole forests
of giant dandelions

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blanket the higher slopes
of the islands.

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But some plants used
a more direct mode of transport,

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than a mere gust of wind.

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A bird.

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The albatross
is the king of long-distance flight.

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It spends most of its life
on the wing.

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But each year it lands somewhere...

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to breed and raise a chick.

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

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provided albatrosses
with a new nesting site.

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And often these huge birds
brought hitchhikers.

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Seeds stuck to their feet
and in their feathers.

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

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with a nice packet of fertilizer.

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So, gradually,
small patches of vegetation

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began to appear
on the newly-emerged islands.

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The seeds of most trees

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

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But those that habitually
grow along the coast,

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can use a different form
of transport.

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This is the seed of a mangrove

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and when it falls,

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it drops into the sea... and floats.

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

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

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But, eventually,
it may float into an estuary.

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And there the water
is brackish and less buoyant.

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So, the heavy end of the seed falls

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and it hangs in the water,
like this.

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And its tip, maybe at low tide,

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trails into the mud and sticks.

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And the mangrove has planted itself.

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

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The young seedlings
quickly establish themselves.

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Their tangled, arching roots
form a grid

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which slows down the tidal water
surging through them,

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causing it to drop its sediment
as mud.

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At low tide, all kinds of creatures

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come out
to scavenge among the roots.

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

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The waters around the tangled roots

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serve as nurseries
for many species of fish.

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So plants created habitats

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

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

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There are some 150 different known
species of them

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in the Galapagos today,

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

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they balloon.

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The hatchlings of many species use
specially adapted silk.

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

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There, it produces
a thread of silk from the spinnerets

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at the end of its abdomen.

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This 3D electron micrograph
shows that this thread is actually

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two filaments that are stuck
together.

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It's flattened like a blade.

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The slightest wind will catch it.

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Once a gust is strong enough,

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the spiderling lets go with its feet
and is carried up

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and away.

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

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

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and doubtless many times since,

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

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And spiders were not alone,
floating through the skies.

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Many different forms of life
were brought

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here by the wind from the
South American continent -

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seeds, pollen,

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viruses, bacteria,

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algae and insects.

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

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They pollinate plants

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

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The species that reached
here are nearly all the smaller

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South American species.

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The bigger ones were too heavy to
make the journey.

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But one quite large insect did so.

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And its arrival started a new
phase in the colonisation

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of the Galapagos.

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It was a beetle.

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Beetles are nature's great
recyclers.

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

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Beetles have sizable bodies
but also large wings.

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That made it possible for one
species to make

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a wind-assisted passage to
the Galapagos.

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Once here,
these beetles began to change.

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Later generations had smaller wings.

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In fact, some Galapagos beetles
lost their wings altogether.

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

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

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equally well carry them off again.

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Insects and plants that were brought
together in this very

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arbitrary way now began to
establish new relationships.

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

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Sometimes, surprisingly perhaps,

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

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Inside this piece of wood,

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

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must certainly have arrived
here in that way.

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This unimpressive little creature
was to be of great help to

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many of the newly-established
plants.

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It fed on their nectar
and pollinated them.

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Carpenter bees are still the main
pollinators on the islands.

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00:23:34,800 --> 00:23:37,880
And the plants have adapted
accordingly.

246
00:23:43,440 --> 00:23:45,799
Nearly all the flowers
on the Galapagos

247
00:23:45,800 --> 00:23:48,360
are now either white

248
00:23:49,040 --> 00:23:51,040
or yellow.

249
00:23:54,320 --> 00:23:57,719
Those are the colours
preferred by the carpenter bees,

250
00:23:57,720 --> 00:24:00,800
so there's no point in being
anything else.

251
00:24:07,920 --> 00:24:10,440
So, land plants flourished.

252
00:24:14,960 --> 00:24:19,120
In the sea, there was another factor
that helped the colonists.

253
00:24:21,840 --> 00:24:26,119
Amazingly, it came not from the
nearest land, South America,

254
00:24:26,120 --> 00:24:28,719
but from 8,000 miles away,

255
00:24:28,720 --> 00:24:32,280
across the Pacific in the
other direction, to the West.

256
00:24:34,840 --> 00:24:38,000
From the tropical
rainforests of New Guinea.

257
00:24:50,000 --> 00:24:53,480
Here there are heavy downpours
every day.

258
00:25:02,520 --> 00:25:06,919
The rain washes
nutrients from the forest soil,

259
00:25:06,920 --> 00:25:11,000
down streams into rivers

260
00:25:12,480 --> 00:25:15,799
and finally, into the ocean.

261
00:25:15,800 --> 00:25:17,839
And there, swept up by the currents,

262
00:25:17,840 --> 00:25:21,520
they're carried across the Pacific
to the Galapagos.

263
00:25:22,600 --> 00:25:24,679
They travel not near the surface

264
00:25:24,680 --> 00:25:29,519
but in the depths, by a cold
water current.

265
00:25:29,520 --> 00:25:33,279
It's one of three that
converge on the islands.

266
00:25:33,280 --> 00:25:35,840
Another comes from the Panama Basin.

267
00:25:37,120 --> 00:25:39,680
And yet another
originates near Peru.

268
00:25:43,120 --> 00:25:46,759
This convergence of currents
has had a remarkable

269
00:25:46,760 --> 00:25:49,160
impact on life in the islands.

270
00:25:55,000 --> 00:25:59,679
Scientists, led by marine biologist
Stuart Banks,

271
00:25:59,680 --> 00:26:02,080
are today investigating
their effect.

272
00:26:07,000 --> 00:26:09,999
Well, Galapagos is
unique in the sense that it's

273
00:26:10,000 --> 00:26:12,679
a system in the Tropics, it's lying
right on the equator under

274
00:26:12,680 --> 00:26:15,239
the strong equatorial sun
and these are usually systems

275
00:26:15,240 --> 00:26:19,079
which are considered to be
deserts for productivity.

276
00:26:19,080 --> 00:26:20,479
But Galapagos is different.

277
00:26:20,480 --> 00:26:24,079
There's a unique confluence
of currents and most importantly,

278
00:26:24,080 --> 00:26:26,799
a submarine undercurrent called
the Cromwell current,

279
00:26:26,800 --> 00:26:30,959
and these undercurrents are bringing
micronutrients up into these

280
00:26:30,960 --> 00:26:31,960
sunlit waters.

281
00:26:34,000 --> 00:26:36,479
The Galapagos Islands
in the open Pacific

282
00:26:36,480 --> 00:26:39,760
lie in the path of these
converging currents.

283
00:26:41,720 --> 00:26:43,479
They deflect the cold,

284
00:26:43,480 --> 00:26:48,480
nutrient-laden waters upwards to
mingle with the warm water above.

285
00:26:49,680 --> 00:26:53,039
This mixing creates ideal
conditions for a vast

286
00:26:53,040 --> 00:26:55,640
community of floating
microscopic plants.

287
00:26:57,120 --> 00:26:59,120
Phytoplankton.

288
00:27:05,080 --> 00:27:09,559
Each tiny organism is only a few
microns across

289
00:27:09,560 --> 00:27:12,360
and invisible to the naked eye.

290
00:27:17,360 --> 00:27:22,960
Yet these specks of life underpin
the whole Galapagos ecosystem.

291
00:27:25,440 --> 00:27:29,079
And here the fertilizer
from New Guinea enables them

292
00:27:29,080 --> 00:27:32,800
to hugely increase in both variety
and number.

293
00:27:41,160 --> 00:27:45,679
Scientists have now discovered
that the islands themselves provide

294
00:27:45,680 --> 00:27:49,960
the phytoplankton with something
that is crucial for its growth.

295
00:27:51,440 --> 00:27:54,639
A vital life-enhancing
element -

296
00:27:54,640 --> 00:27:55,880
iron.

297
00:27:57,000 --> 00:28:00,919
Now the undercurrent which hits
the western side of the archipelago,

298
00:28:00,920 --> 00:28:04,839
it's a bit like imagining pointing
a hose against the side of a wall.

299
00:28:04,840 --> 00:28:10,559
It forms filaments that physically
spread around the archipelago

300
00:28:10,560 --> 00:28:12,160
and up into the surface.

301
00:28:14,040 --> 00:28:16,119
And it's thought that it's
the abrasion

302
00:28:16,120 --> 00:28:18,479
and the leaching
against the volcanic platform

303
00:28:18,480 --> 00:28:23,079
of the islands which is bringing
iron up into the surface waters.

304
00:28:23,080 --> 00:28:25,159
So, thanks to that unique situation,

305
00:28:25,160 --> 00:28:28,479
you tend to get these huge
phytoplankton blooms and this

306
00:28:28,480 --> 00:28:33,760
is literally millions of these tiny
organisms coming together.

307
00:28:37,840 --> 00:28:41,639
This extraordinary image,
based on satellite data,

308
00:28:41,640 --> 00:28:47,000
shows how blooms of phytoplankton
grow and shrink over the seasons.

309
00:28:53,720 --> 00:28:57,679
These astronomic numbers
of microscopic plants support

310
00:28:57,680 --> 00:28:59,960
another vast community.

311
00:29:01,800 --> 00:29:03,120
Microscopic animals -

312
00:29:06,560 --> 00:29:08,400
zooplankton.

313
00:29:12,760 --> 00:29:14,599
Here, under the waves,

314
00:29:14,600 --> 00:29:19,720
there is a living world of
extraordinary complexity and beauty.

315
00:29:23,760 --> 00:29:27,439
All these tiny creatures
are dependent on the rich

316
00:29:27,440 --> 00:29:29,800
blooms of the phytoplankton.

317
00:29:39,520 --> 00:29:41,240
Some graze on them.

318
00:29:47,280 --> 00:29:49,760
Others graze on the grazers.

319
00:29:52,720 --> 00:29:57,240
Many equally extraordinary creatures
feed on the rich soup.

320
00:30:00,360 --> 00:30:02,720
From small crustaceans

321
00:30:06,400 --> 00:30:08,560
and juvenile jellyfish,

322
00:30:09,960 --> 00:30:12,320
to the young of many fish.

323
00:30:25,000 --> 00:30:29,679
These tiny animals and plants,
in turn, support shoals of larger

324
00:30:29,680 --> 00:30:33,279
fish that swarm in such numbers
and variety that they make

325
00:30:33,280 --> 00:30:38,880
the Galapagos waters among the most
diverse of all marine ecosystems.

326
00:30:52,760 --> 00:30:57,520
Many extraordinary creatures feed
directly on the plankton itself.

327
00:30:58,760 --> 00:31:01,239
Garden eels are quite small,

328
00:31:01,240 --> 00:31:04,320
some 15cm or so long.

329
00:31:17,040 --> 00:31:21,360
But much bigger fish also
feed on the plankton.

330
00:31:28,920 --> 00:31:32,800
They, in turn, are food for hunters.

331
00:31:38,360 --> 00:31:41,599
Among them, the Galapagos shark,

332
00:31:41,600 --> 00:31:43,960
a relative of the tiger shark.

333
00:31:53,680 --> 00:31:57,879
And scalloped hammerhead sharks,
which today congregate

334
00:31:57,880 --> 00:32:02,560
here in numbers that are unequalled
anywhere else in the world.

335
00:32:16,160 --> 00:32:20,239
Huge schools of females are often
surrounded by an outer

336
00:32:20,240 --> 00:32:22,759
ring of patrolling males.

337
00:32:22,760 --> 00:32:25,760
No one is quite sure what's
happening at these times.

338
00:32:28,000 --> 00:32:30,600
It's probably
part of their mating behaviour.

339
00:32:52,360 --> 00:32:56,719
Many coastal species are unique
to these islands.

340
00:32:56,720 --> 00:32:59,760
This is the red-lipped batfish.

341
00:33:05,320 --> 00:33:08,319
Its lower fins have been
modified to enable it to

342
00:33:08,320 --> 00:33:10,800
prowl across the seafloor.

343
00:33:14,720 --> 00:33:17,319
The Galapagos sea robin
can also walk

344
00:33:17,320 --> 00:33:21,120
and flashes its bright petrol fins
to frighten away predators.

345
00:33:25,480 --> 00:33:28,639
The trumpetfish
has such an elongated body

346
00:33:28,640 --> 00:33:32,440
that it's hard to see, so it's able
to sneak up on its prey.

347
00:33:45,480 --> 00:33:47,640
And there are giants here too.

348
00:33:52,320 --> 00:33:57,120
This is the Mola Mola, the sunfish.

349
00:33:58,560 --> 00:33:59,719
It's huge,

350
00:33:59,720 --> 00:34:04,000
three metres across and addicted to
lying on its side at the surface.

351
00:34:05,720 --> 00:34:09,160
It eats vast quantities
of jellyfish.

352
00:34:11,680 --> 00:34:17,279
And there are not only fish swimming
in these waters, there are mammals.

353
00:34:17,280 --> 00:34:23,080
Sea lions, whose ancestors
originally came from the coasts of
California.

354
00:34:32,240 --> 00:34:34,839
The Galapagos plankton is
so abundant,

355
00:34:34,840 --> 00:34:39,839
it attracts some of the biggest of
all ocean mammals -

356
00:34:39,840 --> 00:34:41,360
humpback whales.

357
00:34:51,080 --> 00:34:55,760
And rivalling them in size,
the biggest of all fish,

358
00:34:57,960 --> 00:35:00,720
the 20-ton whale shark.

359
00:35:06,120 --> 00:35:10,079
Few parts of the world's oceans can
equal these Galapagos

360
00:35:10,080 --> 00:35:14,360
waters for sheer variety
and abundance of marine life.

361
00:35:18,600 --> 00:35:21,639
And this richness in turn has
attracted a great

362
00:35:21,640 --> 00:35:23,280
variety of sea birds.

363
00:35:29,520 --> 00:35:32,480
Many are long-distance travellers.

364
00:35:36,600 --> 00:35:40,119
The islands have become the best
place in hundreds of square

365
00:35:40,120 --> 00:35:44,720
miles of open ocean for many birds
to rest and to breed.

366
00:35:46,520 --> 00:35:49,879
The Nazca Boobies range
across the whole of the Pacific

367
00:35:49,880 --> 00:35:54,280
but this waved albatross lives
nowhere else but here.

368
00:35:56,680 --> 00:36:01,840
The male frigate bird has a pouch of
scarlet skin hanging from his neck.

369
00:36:03,360 --> 00:36:04,799
During the breeding season,

370
00:36:04,800 --> 00:36:08,520
he inflates it to attract a mate
or see off a rival.

371
00:36:15,360 --> 00:36:17,360
There's also another kind of Booby -

372
00:36:20,320 --> 00:36:22,040
the blue-footed.

373
00:36:29,920 --> 00:36:34,559
His spectacular feet are the key
elements in his courtship

374
00:36:34,560 --> 00:36:37,679
display in which
he tries to persuade his mate

375
00:36:37,680 --> 00:36:41,320
that his really are the bluest
feet around.

376
00:37:06,120 --> 00:37:09,520
Boobies are superb fishermen.

377
00:37:18,360 --> 00:37:23,439
Once they spot a shoal, they fly out
to a height of 25 metres

378
00:37:23,440 --> 00:37:29,160
and then they dive into the water at
speeds of 60 miles per hour or more.

379
00:37:33,080 --> 00:37:38,039
Hitting the water with such force
could kill many birds

380
00:37:38,040 --> 00:37:43,000
but boobies have special air sacs in
their heads that cushion the impact.

381
00:38:10,800 --> 00:38:14,799
Cormorants are coastal birds rather
than ocean travellers

382
00:38:14,800 --> 00:38:18,759
so they can only have arrived
in the Galapagos by accident, having

383
00:38:18,760 --> 00:38:21,519
probably been swept out to
sea by a gale.

384
00:38:21,520 --> 00:38:25,079
But they arrived a very long time
ago

385
00:38:25,080 --> 00:38:26,600
and they stayed.

386
00:38:27,720 --> 00:38:29,679
Like cormorants worldwide,

387
00:38:29,680 --> 00:38:32,840
the Galapagos species is
a superb swimmer.

388
00:38:34,720 --> 00:38:37,320
Its legs are powerful paddles.

389
00:38:46,080 --> 00:38:50,200
And the body itself is
beautifully streamlined.

390
00:38:57,840 --> 00:39:01,520
In effect,
the cormorant flies underwater

391
00:39:02,800 --> 00:39:06,360
and it's certainly able to
out-manoeuvre many a fish.

392
00:39:24,160 --> 00:39:27,520
The Galapagos coast is a great
place for a cormorant.

393
00:39:28,840 --> 00:39:31,880
There are plenty of excellent
nesting sites.

394
00:39:34,920 --> 00:39:38,159
And there are no land predators that
might threaten a bird

395
00:39:38,160 --> 00:39:40,160
sitting in such a vulnerable place.

396
00:39:42,280 --> 00:39:45,159
Its ancestors, when they first
arrived, had wings

397
00:39:45,160 --> 00:39:47,040
like any other cormorant.

398
00:39:50,000 --> 00:39:51,559
But with no need to fly,

399
00:39:51,560 --> 00:39:55,840
its wings over generations became
smaller and smaller.

400
00:40:03,880 --> 00:40:07,920
Now, they are mere stumps with
a few tattered feathers.

401
00:40:11,160 --> 00:40:14,680
So now, the bird can't
fly even if it wanted to.

402
00:40:16,560 --> 00:40:18,279
And since it's flightless,

403
00:40:18,280 --> 00:40:22,319
there is no disadvantage in growing
bigger and the Galapagos

404
00:40:22,320 --> 00:40:25,880
cormorant is now heavier than
any of its flying relatives.

405
00:40:33,200 --> 00:40:36,879
With nothing to hassle it and plenty
of fish in the sea alongside,

406
00:40:36,880 --> 00:40:40,400
the cormorants can now concentrate
on caring for their young.

407
00:40:42,360 --> 00:40:46,560
And in fact, some manage to raise
three broods each season.

408
00:40:56,200 --> 00:41:00,399
But there is another permanent
resident here whose history

409
00:41:00,400 --> 00:41:01,920
is even more remarkable.

410
00:41:06,120 --> 00:41:11,360
Its ancestors lived 5,000 miles
away in the Antarctic.

411
00:41:17,280 --> 00:41:19,080
That creature was a penguin.

412
00:41:21,840 --> 00:41:24,439
Penguins are ocean-going swimmers

413
00:41:24,440 --> 00:41:26,799
but a few thousand years
ago some of them

414
00:41:26,800 --> 00:41:30,799
got caught in the cold waters of the
Humboldt current and were carried

415
00:41:30,800 --> 00:41:35,640
northwards up the coast of South
America and out to the Galapagos.

416
00:41:38,200 --> 00:41:40,479
They could hardly have found
anywhere more

417
00:41:40,480 --> 00:41:42,479
different from their polar home

418
00:41:42,480 --> 00:41:45,319
and in response, they changed.

419
00:41:45,320 --> 00:41:48,839
The emperor penguin that lives
near the South Pole stands over

420
00:41:48,840 --> 00:41:49,840
a metre high.

421
00:41:52,520 --> 00:41:54,879
The Galapagos penguin

422
00:41:54,880 --> 00:41:57,280
is now only half as tall.

423
00:42:07,640 --> 00:42:10,959
And that helps
a lot in the Galapagos.

424
00:42:10,960 --> 00:42:14,840
Small animals lose heat much
faster than big ones.

425
00:42:24,880 --> 00:42:28,760
And the penguins have developed
behavioural tricks as well.

426
00:42:34,800 --> 00:42:37,679
Bare feet are easily sunburnt

427
00:42:37,680 --> 00:42:40,800
so they do their best to keep them
covered.

428
00:42:52,480 --> 00:42:56,160
And some parts of the sea
around the islands are quite cool.

429
00:42:57,360 --> 00:43:01,039
The Humboldt current, flowing
up from the Antarctic and washing

430
00:43:01,040 --> 00:43:04,920
around the western parts of the
archipelago, is still quite chilly.

431
00:43:06,920 --> 00:43:11,279
So, most of the penguins
stay in the channel between the two

432
00:43:11,280 --> 00:43:13,440
western-most islands.

433
00:43:21,680 --> 00:43:26,320
And when things get really hot,
they can still cool off with a swim.

434
00:43:32,400 --> 00:43:34,559
They're quick to detect
the slightest

435
00:43:34,560 --> 00:43:38,479
variation in temperature
and move around to find places where

436
00:43:38,480 --> 00:43:40,840
an eddy might have brought
a pleasing chill.

437
00:43:52,600 --> 00:43:55,799
The arrival of penguins must be
the most unlikely

438
00:43:55,800 --> 00:43:59,920
event in the whole story of the
colonisation of the Galapagos.

439
00:44:02,480 --> 00:44:04,079
But the most important

440
00:44:04,080 --> 00:44:06,920
and influential animals had
yet to appear.

441
00:44:08,880 --> 00:44:10,719
Not birds,

442
00:44:10,720 --> 00:44:12,320
but reptiles.

443
00:44:14,280 --> 00:44:18,919
Many million years ago, somewhere in
South or Central America,

444
00:44:18,920 --> 00:44:21,039
a reptile, an iguana,

445
00:44:21,040 --> 00:44:25,040
was grazing close to the
banks of one of the great rivers.

446
00:44:35,560 --> 00:44:38,920
Perhaps it was
feeding on floating vegetation.

447
00:44:44,000 --> 00:44:47,840
Maybe it fell onto such
a raft from a tree.

448
00:44:52,280 --> 00:44:56,159
Patches of floating
vegetation are still swept

449
00:44:56,160 --> 00:45:00,200
out into the estuaries by flash
floods or tropical storms.

450
00:45:03,440 --> 00:45:05,319
Many are quite big,

451
00:45:05,320 --> 00:45:09,600
and easily buoyant enough to support
a metre-long iguana.

452
00:45:13,440 --> 00:45:18,120
And sometimes, they don't break up
but float out to the open ocean.

453
00:45:21,120 --> 00:45:24,719
Who knows how many thousands
of animals of many kinds have been

454
00:45:24,720 --> 00:45:29,840
lost at sea on rafts like these,
dying from thirst and exposure?

455
00:45:35,040 --> 00:45:37,720
But reptiles are very tough.

456
00:45:42,040 --> 00:45:46,320
They can go without food or
water for days, weeks, even months.

457
00:45:47,760 --> 00:45:52,240
No mammal can survive such
hardships as long as they can.

458
00:45:58,000 --> 00:46:02,239
And, at some point in the history
of the Galapagos, the currents

459
00:46:02,240 --> 00:46:07,560
carried an iguana across 600 miles
of ocean to the islands.

460
00:46:11,040 --> 00:46:14,000
No doubt it happened not once
but several times.

461
00:46:18,120 --> 00:46:21,960
And here, the iguanas settled
and multiplied.

462
00:46:24,320 --> 00:46:26,560
Today, there are thousands of them.

463
00:46:27,600 --> 00:46:32,079
So many, and so widely distributed
throughout the islands,

464
00:46:32,080 --> 00:46:36,200
that they are now one of the
Galapagos' most famous inhabitants.

465
00:46:48,040 --> 00:46:51,840
But these are the most
celebrated of all.

466
00:46:54,840 --> 00:46:57,559
The ones that gave the islands
their name -

467
00:46:57,560 --> 00:46:59,200
giant tortoises.

468
00:47:04,040 --> 00:47:08,039
Tortoises can't swim, but
they can float.

469
00:47:08,040 --> 00:47:12,439
And about three million
years ago, one of them,

470
00:47:12,440 --> 00:47:15,199
a large species from the
South American forests,

471
00:47:15,200 --> 00:47:21,079
was carried away perhaps by
a flash flood and swept out to sea.

472
00:47:21,080 --> 00:47:27,239
After weeks, maybe even months,
they eventually landed on an island

473
00:47:27,240 --> 00:47:32,599
and one of them, perhaps a gravid
female, produced eggs.

474
00:47:32,600 --> 00:47:38,639
As time passed, they spread into
other islands in the archipelago.

475
00:47:38,640 --> 00:47:41,359
Giant tortoises had arrived

476
00:47:41,360 --> 00:47:43,080
in the Galapagos.

477
00:47:51,000 --> 00:47:55,759
With this small selection of animals
and plants in place,

478
00:47:55,760 --> 00:47:58,840
nature's great experiment
gathered pace.

479
00:48:03,280 --> 00:48:06,119
Forged by fire,

480
00:48:06,120 --> 00:48:08,400
fuelled by the ocean,

481
00:48:10,040 --> 00:48:12,200
fanned by the winds

482
00:48:13,960 --> 00:48:18,480
and seeded by a very few
and very different species.

483
00:48:20,600 --> 00:48:24,079
A new community was established
here in the Galapagos,

484
00:48:24,080 --> 00:48:29,479
and one with a very small but very
oddly assorted cast of characters.

485
00:48:29,480 --> 00:48:33,439
There were no amphibians.
Because of their porous skin,

486
00:48:33,440 --> 00:48:35,599
they are poisoned by seawater.

487
00:48:35,600 --> 00:48:39,879
There were no mammals
except for a small short-tailed rat.

488
00:48:39,880 --> 00:48:43,999
Flying insects and seeds of plants
had reached here,

489
00:48:44,000 --> 00:48:45,439
brought by the wind.

490
00:48:45,440 --> 00:48:50,559
But fundamentally, this was
a land of birds which flew here

491
00:48:50,560 --> 00:48:52,880
and reptiles which floated here.

492
00:48:54,280 --> 00:48:57,959
And together, they had to make
a living on this bare,

493
00:48:57,960 --> 00:49:02,839
rocky island that was so crucially
different from the well-watered,

494
00:49:02,840 --> 00:49:05,440
luxuriant forests from which
they had come.

495
00:49:08,440 --> 00:49:12,519
In the next programme,
we will discover how this strange,

496
00:49:12,520 --> 00:49:17,079
oddly assorted cast of characters
learned to colonise even the

497
00:49:17,080 --> 00:49:22,040
most hostile parts of the Galapagos
and to live with one another.

498
00:49:23,960 --> 00:49:26,879
And how they changed in the process.

499
00:49:26,880 --> 00:49:29,519
And we venture even
deeper into the islands,

500
00:49:29,520 --> 00:49:32,039
into places where even today,

501
00:49:32,040 --> 00:49:34,880
new species are being discovered.

502
00:49:41,440 --> 00:49:43,560
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