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 Galapagus. 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 remoter 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, lies 600, miles from the coast of South America and, straddled. The equator. There. Are 16, of them and a, multitude of small, islets. All. Separated. From the rest of the world by, the huge expanse, of ocean. The. Biggest island is Isabela. Lying. In the center of the group it has a strange, seahorse. Like shape. That. Is because, it originated, a six, separate, volcanoes. Which eventually fused, into. One great, island. The, most remote of them is, Alcide, Oh. It's 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. Jaunt. 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, Alcide Oh 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 a hundred 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 the, heyday there. Were 15, species. They. Seemed 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 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's, evidence all around these, islands, of their, direct connection, with the furnaces, deep in the Earth's crust, but. It isn't until recently, that we realize just how close, those, connections, are here. Underneath. The section of the Earth's crust on which, Galapagos sits there, is something, extraordinary. Which. I can't it column, of superheated. Molten, rock rising upwards. This. Hotspot, is immense. At. Least 60. Miles across. It, extends, downwards, for 1,800. Miles and, connects. The islands, to, the very center of the earth. This. Image based, on the very latest seismological. Data, shows. The hotspot from underneath, the cost. 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 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. Far. The. Youngest is. A, Fernandina. It froze, from the sea just 500. Thousand 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. Wins. 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, Galapagus. 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 stereo, baking, hot rocks, but. Just a few were. Luckier. This. Extraordinary. Species is, related, to dandelions. And it's, found a way to grow where. There is neither soil, nor, rain a. Windblown. 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 he. Produced this. Scalisi. 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 use a more direct mode of transport, than, a mere just a 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. Chicken. 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 hitchhikers, 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, mango and. When it falls it. Drops into the sea and, floats. This. Part of it is green. So, 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 s3 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, in may. Be at low tide. Trails. Into, the mud and sticks. And. The mangrove, as, part of itself. These, trees, are very, effective. Colonists. Of newly, formed islands. The. Young seedlings, quickly, established, themselves. They're. Tangled arching, roots form a grid which, slows down the tidal water searching, 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 tangle 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. Then. Some, 150. Different known species of them in the, clavicus, 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. Times 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, let's go with its feet and is, carried, up. And. Away. Some. Can, float up to an altitude of several. Thousand, meters and. Up. There in the Tradewinds 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. And, pollen. Viruses. Bacteria. Algae. And. Insects. Insects. Of course are extremely. Important, in most ecosystems, they. Pollinate, plants and. Their, food from any other kinds. Of animals. This. Species, has reached here 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 and, the colonization. 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 the 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. Of the colors 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 of, 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. They are 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, the cold water, current. It's. One of three that, converts, on the islands. Another. Comes, from the Panama basin, and, yet. Another originates. Near pool. This. Convergence. Of currents, has had a remarkable impact on, life, in the island. Scientists. Led, by marine biologist. Stuart banks, are, today, investigating. Their effect. Well, Galapagus, is unique in the sense that it's. A system in the tropics, it's lying right on the equator under, the Stronach Kotori of sun and these are usually systems, which are very considered.
To Be kind of desert. For productivity. But, Galapagus is different there's a unique confluence. Of currents, and most, importantly, a submarine, undercurrent for the cromwell current and these, under currents, 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 neutral, nadir 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 specs, of life underpinned. The whole galapagos, ecosystem. And here. The fertilizer, from New Guinea enables. Them to huge, the 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, I, am. 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. That, physically, kind of 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 you're talking about literally. Millions of these 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. Zero. Plankton. Here. Under, the waves there. Is a living world of extraordinary. Complexity, and beauty. All, these, tiny creatures are, dependent. On the rich rooms of, the phytoplankton. Some. Graze, on them. Others. Graze. On the graces. Many. Equally. Extraordinary, creatures. Feed, on the rich suit. From, small crustaceans. And juvenile. Jellyfish. To the young of many fish. These, tiny, animals and plants, in turn support. Shows of larger, fish that, swarm in such numbers in 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. 15, centimeters. All 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 unequaled. 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 behavior. Many. Coastal, species are unique, to these islands. This. Is the, red-lipped, batfish. Its, lure fins have been modified to enable, it to prowl across, the seafloor. The. Galapagos, sea Robin can also walk, and flashes. Its bright pectoral, fins to frighten away predators. The. Trumpet fish 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 -. This. Is the. Mola, mola, the. Sunfish. It's. Huge. Three metres across and addicted. To lying on its side of the surface. It. Eats vast. Quantities. Of jellyfish. And. There, are not only fish, swimming, in these waters, there. Are mammals. Sealers. 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. Unpack. Whales. And rivaling. Them in size the. Biggest of all fish. The. 20 ton whale. Shark. Few. Parts, of the world's oceans can, equally, as Galapagos, waters for sheer variety and abundance, of marine life. And this, richness in turn has, attracted, a great variety of seabirds. Many. Are long-distance. Travelers. 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 for 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 sea off arrival.
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 show they, fly up to a height of 25, meters, and, then. They, dive into the water at speeds of 60 miles an hour or more. Eating. 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 travelers so. They can only have arrived here 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 outmaneuver many, a fish. The. Galapagos, coast is a great place for a corner. There. Are plenty of excellent, nesting. Sites. And. Then. Mail and 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 fine 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 managed to raise three, broods each season. But. There is another permanent. Resident, here whose, history is even, more remarkable. It's. Ancestors. Lived, 5000. 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 garbages. They. Could hardly have found anywhere more different, from their polar hole and in, response, they changed. The. Emperor penguin that lives there the South Pole stands, over a metre high. The. Galapagos, penguin, is. Now only half as, tall. And. That helps, a lot in the Galapagus, small. Animals, lose heat much faster, than big ones. And the, Penguins, have developed, behavioral. Tricks as well. Their. Feet are easily. Sunburned, 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 westernmost. Islands. And. When. Things get really hot they, can still cool off with, a swim. They. Quickly detect, the slightest, variation in, temperature, and move, around to, find places where an eddy might have water pleasing, chill. The. Arrival, of penguins, must, be the most unlikely, event, in the whole story, of the colonization. Of the kalapa goose. 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 meter 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. The 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 come. And at. Some point in the history of the Galapagus 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 iguana's, 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, is 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, 3, 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, and arrived in the, Galapagos. With. This small, section. Of animals, and plants, in place, nature's. Great experiment. Gathered. Pace. Forged. By far. Fueled. 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 now amphibians. Because. Of their porous, skin they're, poisoned, by seawater there. Were no mammals except. For a small short, tailed rat. Flying. Insects. And seeds of, plants had, reached here bought, 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'd come. In the next program we, will discover how this strange, oddly. Assorted, cast of characters, learn. To colonize, even. The most hostile, parts, of the Galapagos, and. To live with, one another. And how they change it in the process and, we. Venture even deeper, into the islands, into. Places, where even today new. Species, are being discovered. You.
2018-04-08