Casi doscientos años después de la llegada de Charles Darwin a las islas Galápagos, el naturalista David Attenborough viaja a este maravilloso archipiélago perdido en la inmensidad del Pacífico para descubrirnos sus secretos. Nosotros le acompañaremos a lo largo de tres episodios.
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00:00In the immensity of the Pacific there is a place different from any other.
00:06Enchanted volcanic islands that house an extraordinary collection of animals and plants.
00:17Here, evolution advances at a spectacular speed.
00:31Black lizards that swim in the ocean and spit salt out of their noses.
00:39Penguins thousands of kilometres from Antarctica.
00:45And a great abundance of endemic plants.
00:51Some animals are small, and others have just been discovered.
01:00This is a place of wonders.
01:07The Galapagos.
01:12Islands born of fire.
01:16With inhabitants that have transformed our global understanding of life on Earth.
01:25The Galapagos Islands.
01:30In a lifetime dedicated to making documentaries of natural history,
01:34I have been to many wonderful places.
01:37But none more extraordinary than this one, the Galapagos Islands.
01:42These have been called the most prodigious experiment of nature,
01:46for here life has evolved in isolation and produced some extraordinary results.
01:53Origin.
02:01The extraordinary creatures of the Galapagos amazed Charles Darwin
02:05when he arrived here for the first time 200 years ago.
02:12The Galapagos Islands.
02:18The Galapagos Islands.
02:22They led him to formulate his revealing theory of evolution through natural selection.
02:32And now, 200 years later, there are still mysteries to be solved,
02:37and new discoveries to be made.
02:43Scientific teams are investigating unexplored regions of the most remote islands,
02:48and discovering unknown animals until now.
02:53On the peaks of their volcanoes.
02:57Within networks of immense tunnels inside lava flows.
03:03And in their crystalline waters.
03:08Between a population of giants,
03:10and in the magical world that the microscope reveals to us.
03:15New technologies allow scientists to investigate the functioning of evolution in new ways.
03:24And to gather knowledge that would have amazed Darwin himself.
03:32Today we know much more about these islands.
03:36The discovery of new species,
03:38extensive studies that have been carried out over decades,
03:41have given us new perspectives, not only of this place,
03:45but of the evolutionary process throughout the planet.
03:55The archipelago is located about 1,000 km from the coasts of South America,
03:59around the line of the terrestrial equator.
04:02It is composed of 16 islands and a multitude of small islets,
04:07all separated from the rest of the world by the huge oceanic extension.
04:15The largest island is Isabela.
04:21Located in the center of the group, it has a strange shape of a seahorse.
04:26And this is due to the fact that in its origin there were six separate volcanoes,
04:30which finally merged, forming a large island.
04:40The most remote is the volcano Alcedo.
04:44Its immense crater is about 6.5 km in diameter.
04:53Its huge and steep walls, still steaming with jets of gas and volcanic steam,
04:58make it one of the most isolated places in the galaxy.
05:05The crater is the largest in the world.
05:08And it has become a sanctuary for one of the most spectacular inhabitants of the island.
05:22The giant tortoise.
05:33The giant tortoise.
05:39The giant tortoise.
05:49There are thousands of them.
06:00These are the extraordinary creatures that gave these islands their name.
06:09Galápagos, in Spanish, similar to tortoise.
06:12And here in the crater of the volcano Alcedo,
06:15they have congregated in quite numerous groups,
06:18to revolt in the warm volcanic mud.
06:22A big specimen can weigh up to a quarter of a ton.
06:25They live 100 years or more,
06:27which makes them the longest of all vertebrates.
06:30And being reptiles, they get their energy by sunbathing.
06:34And they are very fast.
06:36And they are very fast.
06:38And they are very fast.
06:40And they are very fast.
06:42And they are very fast.
06:44And they are very fast.
06:46And they are very fast.
06:49And they are very fast.
06:51And they are very fast.
06:53And they are very fast.
06:55And they are very fast.
06:57And they are very fast.
06:59And they are very fast.
07:07The existence of creatures like these,
07:09so far away from the nearest continent,
07:11raises many questions.
07:18For example, how did these huge animals get to these islands?
07:29But perhaps the most extraordinary thing about the Galapagos turtles is that they are not all the same.
07:38Different islands have different species.
07:43In their heyday, there were 15 different species.
07:48They seem to have emerged in an opening and closing of evolutionary eyes.
07:55In this small group of islands.
08:02And in this one, the turtles are not alone.
08:05Almost all the animals and plants on the island have a similar history.
08:17The colonizing animals began to change from the moment they arrived,
08:22pushed by the inhospitable volcanic landscape that surrounded them.
08:36There is evidence of their direct connection to the ovens,
08:40located at great depth under the earth's crust.
08:44But it was not until recently that we realized how close those connections are here.
08:54Under the section of the earth's crust on which the Galapagos settle, there is something extraordinary.
09:06A gigantic column of super-hot molten rock that moves upwards.
09:15This hot spot is immense,
09:19with a diameter close to 100 kilometers.
09:23It extends downwards, over 2,900 kilometers,
09:28and connects the islands with the very center of the earth.
09:32This image, based on the most recent seismological data,
09:37shows the hot spots under the earth's crust.
09:45This is the source of volcanic activity on the islands.
09:53It began to build the Galapagos 4 million years ago.
10:02The Galapagos is the largest volcanic volcano in the world.
10:08It is the largest volcanic volcano in the world.
10:12It is the largest volcanic volcano in the world.
10:16It is the largest volcanic volcano in the world.
10:20It is the largest volcanic volcano in the world.
10:24It is the largest volcanic volcano in the world.
10:28It is the largest volcanic volcano in the world.
10:42A series of islands emerged from the depths of the sea.
10:46There are currently 16 of them, and all of them are volcanoes.
10:53Most are extinct, and the oldest are collapsing into the sea.
11:04But the youngest islands are still active,
11:08and they expect to erupt one day.
11:15The youngest of all is Fernandina.
11:21It emerged from the sea only 500,000 years ago.
11:27And while it is still active,
11:30the lava fields that cover it still do not suffer the effects of erosion.
11:35And here, in this desolate paramo,
11:39we can see how the ingredients of an extraordinary natural experiment were fused.
11:43we can see how the ingredients of an extraordinary natural experiment were fused.
11:51Fate placed these islands in a unique place on this planet.
11:55They are located directly on the equator,
11:58with its heat and its sunlight throughout the year.
12:02But perhaps even more important,
12:05they are located at the confluence point of two powerful winds that compete with each other.
12:14The winds from the southeast blow from South America,
12:19and the winds from the northeast blow from the Caribbean and Central America.
12:30These two winds are the source of life for the Galapagos.
12:35They transported the first settlers to the emerging volcanic islands.
12:41They transported the first settlers to the emerging volcanic islands.
12:49Seeds fallen from the trees in Central and South America
12:53were pushed by the wind along thousands of kilometers of ocean.
12:58Most were lost in the water.
13:00Of the few that reached the islands, many fell on scorching and sterile rocks.
13:05And only a few were more fortunate.
13:09This extraordinary species is related to the lion's teeth,
13:13and has managed to grow in a place where there is no land or rain.
13:20A wind-blown seed arrives, dragged by the wind, and falls into a crack in the lava.
13:25Moisture accumulates and causes it to germinate.
13:29With its tiny leaves, it manages to absorb more moisture
13:34and the infinitesimal amount of nutrients that the steam that floats in the air can contain.
13:40Some of these leaves may seem dry, and in fact they are.
13:45The plant is deliberately changing them.
13:49It is ensuring that the leaves are not dry.
13:52It is ensuring that nothing of what it produces is wasted.
13:56It is creating its own soil.
13:59And eventually, after 80 or 100 years, it produces this.
14:06Scalesia, which seems to grow directly from the bare rock.
14:14After some very modest beginnings,
14:17this extraordinary plant has been strengthening more and more.
14:21Today, entire forests of giant lion's teeth cover the highest slopes of the island.
14:29But some plants use a means of transport more direct than a mere gust of wind.
14:37A bird.
14:40The albatross is the king of long-distance flights.
14:45It spends most of its life in the air.
14:48But every year, it lands somewhere to reproduce and raise a chick.
15:03The appearance of a new island in the middle of the ocean
15:06gave the albatross a new place to nest.
15:11And often, these huge birds brought passengers.
15:17The seeds were trapped in their legs and between their feathers.
15:22And they may even have provided their passengers
15:25with a little help in their vital beginning with a good package of fertilizer.
15:35So, gradually, small areas of vegetation began to appear on the newly emerged island.
15:42The seeds of most trees are too large to be transported long distances by birds or the wind.
15:49But those that usually grow along the coast can use another different means of transport.
15:56This is the seed of a mangrove.
15:59And when it falls, it drops into the sea and floats.
16:05This part is green, so it can make you look like an albatross.
16:11And the seed can remain at sea for a very long time.
16:16But at the end, it may float to a pond, and there the water is saltier and less buoyant.
16:23So the heaviest part of the seed falls and it hangs in the water like this.
16:30And the tip, probably during the low tide,
16:33comes in contact with the mud and penetrates it.
16:38And the mangrove has planted itself.
16:42These trees are very effective colonizers of the newly formed islands.
16:51The young mangroves ripen rapidly.
16:58Their curved and tangled roots form a grid
17:01that slows down the passage of the tide when it crosses them,
17:05causing it to release its sediment and deposit itself in the form of mud.
17:09In the low tide, all kinds of creatures come to the surface to lurk among the roots.
17:20And when there is high tide, other creatures come swimming to find shelter.
17:32The waters that surround the tangled roots serve as a breeding ground for many species of fish.
17:40The fish are the main source of food for the mangroves.
17:49So the plants created habitats where the animals could survive,
17:53both in the water and outside it.
17:56Some of the first animals to arrive on these islands were spiders.
18:06Today, there are around 150 different species known in the Galapagos.
18:13And they travel in a completely different way.
18:17They come to the Galapagos in large numbers.
18:20The young of many species use a specially adapted silk.
18:28A young mangrove climbs to the tip of a leaf or a branch.
18:32There it produces a silk thread with the rows located in the center.
18:39The silk thread is then woven into the thread.
18:42This electronic 3D scanning shows that this thread is actually made up of two filaments that are glued together.
18:49It is as flat as a knife.
18:53The light wind will catch it.
18:58The silk thread is then woven into the thread.
19:03The silk thread is then woven into the thread.
19:07The light wind will catch it.
19:12When a gust is quite strong, the spider's egg is propelled with its legs and is raised.
19:20And transported.
19:23Some of them can float up to a height of several thousand meters.
19:28And up there, in the winds of the Alices, millions of years ago,
19:32and without a doubt many times since then,
19:35some of them made the journey of a thousand kilometers to the Galapagos.
19:40The Galapagos is one of the most beautiful places in the world.
19:44And the spiders were not alone, floating through the sky.
19:54Many different life forms were brought here by winds of the South American continent.
20:00Seeds and pollen, viruses, viruses, all these beings will be transformed.
20:07It works amazingly when you are going up to the sky,
20:12pollen, viruses, bacteria, algae, and insects.
20:18Insects, of course, are extremely important in most ecosystems.
20:23They pollinate plants and they are food for many other types of animals.
20:29The species that have reached this point are the smaller South American species.
20:34The bigger ones were too heavy to make the trip.
20:40But a rather large insect did.
20:47And its arrival marked the beginning of a new stage in the colonization of the Galapagos.
20:57It was a beetle.
21:02Beetles are the great recyclers of nature.
21:06They chew organic matter and that helps to create fertile soil.
21:15Beetles have quite considerable bodies, but also large wings.
21:21And this made it possible for a species to make a trip, with the help of the wind, to the Galapagos.
21:37Once here, these beetles began to change.
21:43The later generations had smaller wings.
21:48In fact, some beetles of the Galapagos lost their wings completely.
21:55The specimens with the smaller wings had a much greater chance of staying.
22:01And this is because the large wings that have brought the beetles here
22:05can in the same way bring them back.
22:13The insects and plants that were moved together in this arbitrary way
22:17began to establish new relationships.
22:22But one in particular had the effect of a great reach.
22:26Sometimes, surprisingly perhaps,
22:29flying insects arrived in the Galapagos, not by air, but by sea.
22:35Inside this piece of wood, there is a nest of a little carpenter bee,
22:40whose ancestors undoubtedly must have arrived here in that way.
22:49This insignificant little bee,
22:53this insignificant little creature,
22:56was going to be a great help for many of the newly rooted plants.
23:07It fed on its nectar and pollinated them.
23:12The carpenter bees are still the main pollinators of the islands.
23:18And the plants have adapted as a result.
23:27Almost all the flowers of the Galapagos are currently white,
23:32or yellow.
23:35These are the colors preferred by the carpenter bees,
23:39so it makes no sense to be otherwise.
23:48And so, the terrestrial plants flourished.
23:55In the middle of the Galapagos,
23:57there is a small island of the Galapagos,
24:01where there was another factor that helped the colonizers.
24:09Surprisingly, it did not come from the nearest land, South America,
24:13but from the west, just in the opposite direction,
24:16about 13,000 kilometers away through the Pacific Ocean,
24:21from the tropical forests of New Guinea.
24:31Here, strong waterfalls fall every day.
24:46The rain drags the nutrients from the soil of the forests,
24:50up to the streams.
24:53From there, they pass to the rivers.
24:56And finally, they reach the sea.
24:59There, pushed by the currents,
25:01they travel through the Pacific Ocean to the Galapagos Islands.
25:06They do not do it near the surface,
25:08but in the depths, transported by a stream of cold water.
25:13It is one of the three that converge on the islands.
25:17Another comes from the Panamanian Basin.
25:20And the third originates near Peru.
25:26This convergence of currents
25:28has had an extraordinary impact on the life of the islands.
25:40Some scientists, led by Stuart Banks, a marine biologist,
25:43are currently investigating its effects.
25:47The Galapagos Archipelago is located
25:49right on the line of the equator, under the intense equatorial sun.
25:53This is why it is usually considered
25:55as a kind of desert in terms of productivity.
25:58However, the Galapagos are different.
26:00There is a unique confluence of currents in them,
26:03among which the Cromwell Submarine Current stands out.
26:06These currents already reach the Pacific Ocean,
26:09but the Galapagos are different.
26:11The Galapagos are different because the Galapagos
26:14and the Cromwell Submarine Current
26:16reach these waters bathed in the sun.
26:23The Galapagos Archipelago is located
26:25in the middle of the Pacific Ocean,
26:27right on the line of these converging currents.
26:30Its islands diverge the cold waters
26:32and loaded with nutrients towards the surface,
26:35where they mix with the warmer waters of the upper layer.
26:39This mixture creates the ideal conditions
26:41for a large community of floating microscopic plants,
26:46the phytoplankton.
26:54Each of these tiny organisms
26:56is only a few microns in diameter
26:58and are invisible at first sight.
27:06However, these life specimens
27:08sustain the entire ecosystem of the Galapagos.
27:14And here, the fertilizer from New Guinea
27:17allows them to grow enormously,
27:19both in quantity and variety.
27:30Scientists have now discovered
27:32that the islands themselves provide the phytoplankton
27:35with something crucial for their growth,
27:40an essential element for the development of life,
27:43iron.
27:46When the underground current
27:48hits the western part of the archipelago,
27:50it produces an effect similar to that of a hose
27:53pointing towards a wall.
27:55It forms a series of filaments
27:57that spread around the archipelago
27:59and rise to the surface.
28:02It is thought that this abrasion and absorption effect
28:05against the volcanic platform of the islands
28:08is what transports the iron mineral
28:10to the summer waters.
28:12Thanks to this exceptional situation,
28:14huge growth of phytoplankton
28:16tends to occur,
28:18concentrations of millions of these tiny organisms.
28:26These extraordinary images,
28:28created from data obtained
28:30by satellites,
28:32show us how phytoplankton
28:34flourishes and grows
28:36throughout the seasons.
28:42These astronomical quantities
28:44of microscopic plants
28:46provide sustenance for another vast community.
28:50Microscopic animals.
28:55Zooplankton.
29:01Here, under the waves,
29:03there is a living world
29:05of extraordinary complexity and beauty.
29:13All these tiny beings
29:15depend on the rich flowering of phytoplankton.
29:19Some graze on them.
29:27Others feed on those who graze on them.
29:33Many equally extraordinary creatures
29:35feed on this rich broth.
29:40The phytoplankton
29:42is the only living organism
29:44in the world
29:47from tiny crustaceans
29:54to young jellyfish
29:57to the young of many fish.
30:12These tiny animals and plants
30:14provide sustenance
30:16for large fish banks
30:18that gather in large numbers
30:20and turn the waters of the Galapagos
30:22into one of the most diverse
30:24marine ecosystems on the planet.
30:27Plankton.
30:42Numerous and extraordinary creatures
30:44feed directly on plankton.
30:48Garden eels are quite small.
30:50They are about 15 centimetres long.
30:57But other, much larger fish
30:59also feed on the microscopic plankton.
31:10And they constitute, in turn,
31:12the sustenance of predators.
31:21The phytoplankton
31:23is the largest fish in the world.
31:27Among them, the Galapagos shark,
31:29a relative of the tiger shark.
31:42And the hammerhead shark,
31:44which today congregates here
31:46in quantities that have no equal
31:48in any other corner of the planet.
31:54The Galapagos shark
31:56is one of the largest fish in the world.
31:58It is the largest fish in the world.
32:05Large female banks
32:07are often surrounded
32:09by an outer ring of males
32:11patrolling around them.
32:13No one knows for sure
32:15what is happening at the moment.
32:17It is likely that it is part
32:19of their mating ritual.
32:23Many coastal species
32:25are exclusive to these islands,
32:27such as the batfish,
32:29with red lips.
32:54Its lower fins have been modified
32:56to allow it to move
32:58along the seabed.
33:03The red-faced flying fish
33:05can also walk,
33:07as long as it moves
33:09its bright pectoral fins
33:11to scare away predators.
33:14The trumpet fish has such a long body
33:16that it is difficult to see,
33:18which allows it to approach
33:20its prey with stealth.
33:23And there are also giants here.
33:41This is the mola mola,
33:43the moon fish.
33:47Its size is enormous.
33:49It has three meters of wingspan
33:51and likes to lie down
33:53on the surface.
33:55It feeds on large amounts
33:57of jellyfish.
34:01And not only fish
34:03swim in these waters,
34:05but also mammals,
34:07such as the sea lions,
34:09whose ancestors originally
34:11arrived from the coasts of California.
34:21Plankton is so abundant
34:23in the Galapagos
34:25that it attracts some
34:27of the largest
34:29of all marine mammals,
34:31the humpback whales.
34:41And rivaling them in size,
34:43the largest of all fish,
34:47the whale shark,
34:49weighs about 20 tons.
34:55Few places on the seas
34:57of our planet can compare
34:59to these waters of the Galapagos
35:01in terms of diversity
35:03and abundance of marine life.
35:07And this wealth
35:09has attracted a large variety
35:11of marine birds.
35:19Many of them
35:21are long-distance travelers.
35:25The islands have become
35:27the most suitable place
35:29for hundreds of square kilometers
35:31of open sea for the multitude
35:33of birds that come here
35:35to rest and breed.
35:37The Nazca pike extends
35:39throughout the Pacific,
35:41but this wavy albatross
35:43has not nested anywhere
35:45except here.
35:47It has a scarlet skin bag
35:49that hangs from its neck.
35:53During breeding season,
35:55the albatross attracts
35:57a mate or drives away
35:59its rivals.
36:05There are also other types
36:07of pikemen,
36:09like this one
36:11with blue legs.
36:18Its spectacular limbs
36:20are a key element
36:22in its courtship ritual,
36:24in which it tries to convince
36:26its mate that its legs
36:28are really the bluest
36:30of all.
36:48The pikemen
36:50are excellent fishermen.
37:06When they spot a bank
37:08of fish, they fly up
37:10to a height of 25 meters
37:12and then jump into the water
37:14at speeds that reach
37:16100 kilometers per hour
37:18or even more.
37:22Hitting the water
37:24with such force
37:26could kill many of these birds,
37:28but the pikemen have
37:30special airbags
37:32on their heads
37:34that cushion the impact.
37:47The albatrosses are not
37:49oceanic travelers,
37:51but coastal birds,
37:53so they could only
37:55reach the Galapagos Islands
37:57by accident,
37:59probably dragged
38:01by strong winds
38:03towards the open sea.
38:05But they arrived a long time ago
38:07and stayed.
38:17The albatross of the Galapagos,
38:19like the one of other species
38:21distributed around the world,
38:23is an excellent swimmer.
38:25Its legs are powerful oars
38:35and its own body
38:37is wonderfully aerodynamic.
38:47In fact, the albatross
38:49flies underwater
38:51and is undoubtedly able
38:53to take advantage of many fish.
39:13The coast of Galapagos
39:15is an ideal place for the albatross.
39:17There are a lot of excellent
39:19nesting sites.
39:24And there are no terrestrial predators
39:26that can represent a threat
39:28to a bird lodged
39:30in such a vulnerable place.
39:32When they arrived here
39:34for the first time,
39:36their ancestors had wings
39:38equal to those of any other albatross.
39:40But without the need to fly,
39:42with the passage of generations,
39:44their wings became smaller and smaller.
39:53Now they are simple fins
39:55covered with a few feathers.
40:00So now the bird could not fly
40:02even if it wanted to.
40:05And being unable to fly,
40:07getting bigger and bigger
40:09is not a disadvantage.
40:11So the albatross of Galapagos
40:13is much heavier than any
40:15of its flying relatives.
40:22With nothing overwhelming them
40:24and plenty of fish at their reach
40:26in the sea,
40:28the albatross can concentrate
40:30on taking care of their chicks.
40:32In fact, some manage
40:34to raise three nests
40:36each season.
40:44But there is another
40:46permanent resident here,
40:48whose story is even more remarkable.
40:54His ancestors lived
40:568,000 kilometers away,
40:58in Antarctica.
41:06The creature we are referring to
41:08was a penguin.
41:10Penguins are ocean swimmers.
41:13But a few thousand years ago
41:15some were trapped in the cold waters
41:17of the Humboldt Current
41:19and were dragged north,
41:21to the coasts of South America
41:23and the Galapagos Islands.
41:27They could hardly have found
41:29another place so different
41:31from their home on the pole.
41:33And in response to this, they changed.
41:35The penguin emperor,
41:37who lives near the South Pole,
41:39is over one meter tall.
41:41The Galapagos penguin
41:43is now only half his height.
41:56And that helps a lot
41:58in the Galapagos Islands.
42:00The small animals lose their heat
42:02much faster than the big ones.
42:12And the penguins
42:14have also developed
42:16behavioral strategies.
42:23The naked legs burn easily
42:25in the sun,
42:27so they do everything possible
42:29to keep them covered.
42:41And some areas of the sea
42:43that surround the islands
42:45are quite cool.
42:47The Humboldt Current,
42:49which rises from Antarctica
42:51and bathes the western part
42:53of the archipelago,
42:55is still quite cold.
42:57That is why most penguins
42:59remain in the channel
43:01that separates the two western islands.
43:03And when the heat
43:05is too intense,
43:07they can always
43:09cool down with a splash.
43:15The penguin quickly detects
43:17the slightest variation
43:19in temperature
43:21and moves from one place
43:23to another
43:25to find places
43:27where a whirlpool
43:29may have brought
43:31a pleasant coolness.
43:41The arrival of the penguins
43:43had to be the most
43:45unbelievable event
43:47in the history
43:49of the colonization
43:51of the Galapagos Islands.
43:53But the most important
43:55and influential animals
43:57of the archipelago
43:59are not the birds,
44:01but the reptiles.
44:03Many millions of years ago,
44:05somewhere in South or Central America,
44:07a reptile,
44:09an iguana,
44:11grazed along the banks
44:13of one of its great rivers.
44:25Perhaps it was feeding
44:27on floating vegetation.
44:33Or perhaps it fell from a tree
44:35to this kind of raft.
44:41Tropical storms
44:43and floods still drag
44:45pieces of floating vegetation
44:47towards the estuaries.
44:53Many of them are quite large
44:55and have enough buoyancy
44:57to hold an iguana
44:59of one meter in length.
45:03And sometimes they don't break,
45:05but float to the open sea.
45:11Who knows how many thousands
45:13of animals of different species
45:15have drifted to the sea
45:17in rafts like these
45:19and have died of thirst and insolation.
45:25They are very resistant.
45:31They can survive without eating
45:33or drinking for days, weeks
45:35or even months.
45:37No mammal is capable
45:39of enduring such harsh conditions
45:41for so long.
45:47And at some specific moment
45:49in the history of the Galapagos Islands,
45:51the currents transported an iguana
45:53across 1,000 kilometres of ocean
45:55to the archipelago.
45:59There is no doubt
46:01that this happened several times.
46:07And once here,
46:09the iguanas established themselves
46:11and multiplied.
46:13Today there are thousands of them,
46:15so many and so widely distributed
46:17across all the islands
46:19that they have become
46:21one of the most well-known
46:23inhabitants of the Galapagos.
46:37But these are the most popular
46:39creatures of all,
46:43for whom the islands
46:45receive their name,
46:47the giant turtles.
46:51The giant turtles
46:53don't know how to swim,
46:55but they can float.
46:57And about three million years ago,
46:59one of them,
47:01belonging to a large species
47:03that inhabited the forests
47:05of South America,
47:07was perhaps caught
47:09by a sudden flood
47:11and dragged to the sea.
47:13After several weeks
47:15or even months,
47:17it finally landed on an island
47:19and produced eggs.
47:21As time went on,
47:23they spread to other islands
47:25of the archipelago.
47:27Giant turtles
47:29had arrived in the Galapagos.
47:39With this small selection
47:41of animals and plants
47:43in its place,
47:45the great experiment
47:47began.
47:51Forged by fire,
47:55fed by the ocean,
47:59fanned by the winds
48:03and sown by very few
48:05and very different species.
48:09A new community
48:11was established here in the Galapagos,
48:13a very small community
48:15but with a surprisingly varied
48:17cast of characters.
48:19There were no amphibians
48:21because the sea water
48:23intoxicates their porous skin.
48:25There were no mammals
48:27except for a small short-tailed rat.
48:29Flying insects
48:31and some plant seeds
48:33arrived here transported by the wind,
48:35but fundamentally
48:37it became a territory of birds
48:39that flew through the air
48:41and reptiles
48:43and both species
48:45had to learn to survive
48:47in these islands of bare rock
48:49so diametrically different
48:51from the humid and lush forests
48:53from which they came.
48:57In the next program
48:59we will discover
49:01how this strange and surprisingly
49:03varied cast of characters
49:05learned to colonize
49:07even the most hostile places
49:09of the Galapagos
49:11and how they evolved
49:13during the process
49:15and we will delve
49:17even more into the islands
49:19in places where
49:21new species are still
49:23being discovered today.
49:41www.subsedit.com