"Garden of Eden"

PBS Airdate: November 28, 2000
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NARRATOR: Long ago, voyagers in the Indian Ocean chanced upon a large, floating object of mysterious origin. Its suggestive feminine shape launched many a sailor's fantasy. Some believed this was the forbidden fruit that tempted Adam, and somewhere nearby must be the original Garden of Eden.

Eventually, the exotic seed was discovered on a gigantic female palm tree known as the "coco de mer." Like Eve, she too must have an Adam, the male coco de mer palm with its giant pollinating appendage. This tree is a vestige from the vanished world of the dinosaurs; and it shares the forest with other Jurassic-aged giants, dwarfs and many other bizarre forms of life.

This lost world is hidden in a cluster of islands called the "Seychelles." Tiny specs of land a thousand miles from anywhere, the Seychelles lie in the middle of the Indian Ocean between Africa and India. These remote islands conceal an astonishing array of life and are a refuge for strange creatures found nowhere else on Earth. How this living paradise came to be is an extraordinary tale.

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NARRATOR: In the middle of the Indian Ocean lies the Seychelles, a remote group of islands that pose a baffling puzzle.

Deep in the misty uplands of one island hides a tiny creature that should not be there. The pygmy piping frog is one of the smallest vertebrates on earth. The adult frog is not much larger than an ant. Unlike most amphibians, this frog lays its eggs on dry land. Enclosed in these watery egg cases, the babies go through the entire tadpole stage before they hatch.

On a small rocky island with few fresh water pools this is an advantage. After three to four weeks the bubble bursts and a fully formed frog emerges in miniature.

But frogs rarely colonize ocean islands. These amphibians are delicate. The salt, sun and heat of an accidental ocean voyage would surely kill them. So how did they get here?

The frogs, and the other curious creatures that inhabit these secluded islands, have long been a mystery. The tiger chameleon's closest relatives are found in Africa. Disguised as the foliage, the leaf insect is almost invisible. This insect's nearest ancestors come from Asia. Both are masters of camouflage, perfectly adapted to their environment.

The chameleon's disguise and time-tested strategies ensure a meal is never far out of reach. Its eyes rotate independently, allowing it to see in two directions without having to move its head. Poised, at just the right moment its spring-loaded tongue shoots out and reels in its unwitting victim.

The presence of an African chameleon here, on a distant outpost in the Indian Ocean, is as remarkable as the presence of this exotic plant. The pitcher plant's closest cousins are in Malaysia.

To survive on rocky outcrops with little soil and few nutrients, the pitcher plant has evolved an ingenious method to supplement its diet. The plant secretes a sugary nectar that lures an unsuspecting fly. It proves to be a fateful slip. Slowly drowning in the lethal digestive juices, this fly has no chance of escape.

These mosquito larvae are somehow immune to the plant's toxic water. It's a perfect nursery—safe, with a steady supply of food. The larvae pay their way by helping the host plant to digest its catch.

A hungry skink is on the prowl, looking to take advantage of the pitcher plant and its pantry of ready-made insect meals.

So how could a plant whose closest relatives are in the Orient and creatures with distant cousins in Africa and Asia all end up here together on a remote group of islands, a thousand miles from the nearest mainland?

The search for an answer begins with the rock. These time-eroded formations are granite, a type of bedrock usually found on continents. But here, far from any continent, are the Seychelles, the only islands in the middle of an ocean made of solid granite.

The secret of their origin stretches far back in time. Two hundred million years ago the earth was divided into two great landmasses, Laurasia and Gondwana. The southern super-continent Gondwana included present-day Africa and India. Then during the middle of the Jurassic period, Gondwana began to split up. The sea filled a rift between Africa and India to form the early Indian Ocean. Then India broke from Madagascar and began to drift northward.

About 65 million years ago, fragments of the ancient landmass were torn off, leaving behind the central granite islands of the Seychelles.

These peaks are the highest points on a now submerged remnant of ancient continent. On the largest of these granite islands are surviving relics from the lost world of Gondwana.

This forest is a living Jurassic Park of palms. The trees are direct descendants from an age when the dinosaurs roamed and all life grew much bigger. In this age-old forest one palm tree reigns supreme.

The extraordinary coco de mer holds the record for the largest leaf and the biggest seed in the entire plant kingdom. So rare, early sailors thought they came from a tree growing beneath the ocean. The mysterious nuts came to be called coco de mer or "coconut of the sea."

Since only the hollow rotten nuts float, these palms never spread to new shores. One of the coco de mer's last remaining strongholds is a large grove on this granite island. Here, the trees can grow up to a hundred feet tall in the sheltered quiet of this ancient valley.

The male coco de mer tree boasts an enormous catkin, which can grow to more than five feet in length. This male reproductive organ is so large it supports its own mini-ecosystem. The ripe pollen-laden flowers are a magnet for visitors of all kinds. The giant white slug's only home is on these catkins. The day gecko also spends most of its life here, feasting on the rich supply of pollen. Microscopic hairs on its feet help it cling to almost any surface. Topside or bottom, no area of the catkin is beyond reach.

No one knows whether it is one of these creatures or the wind that carries pollen to the female coco de mer. An old Seychelles legend says the trees consummate their union by swaying together on stormy nights. However it occurs, it is the start of something big.

Once the female tree is pollinated, it takes seven years for the nuts to mature. A single nut can weigh in at 40 pounds. Too large to be carried away by a bird and too heavy to float, a fertile coco de mer seed never left this Eden until humans came.

Now park rangers must tightly control the harvest of the nuts to safeguard a future for these ancient palms.

Stripping away the outer husk reveals the curiously shaped seed inside. The double lobes of the coconut account for its suggestive appearance. When sold, these so-called "love nuts" will help pay for the preservation of this unique nature reserve.

Today tourism in the Seychelles is carefully managed to preserve the islands' precious natural heritage. The highlight of any trip is a visit to the smaller, undeveloped granite islands, which are a haven for rare and unusual species.

Separated for generations from their mainland ancestors, many birds have evolved into new forms found only on these islands. One bird, the magpie robin, seems to have adapted its behavior to take advantage of the tourist activity. The visitors' footsteps stir up leaf litter, exposing the insects hiding underneath. The robin tags along behind, cleaning up as it goes.

But whose trail did the robin follow before the people arrived? This hulking creature—the giant tortoise. Weighing more than 600 pounds, the lumbering tortoise plows up the soil, exposing beetles, worms and other treats for the foraging robin.

The Seychelles magpie robin is one of the rarest birds in the world. Fewer than 100 individuals now remain. A tame ground feeder, this bird had few predators until the arrival of humans—and the cats and rats that came with them. The tortoise and the robin struggle to maintain a fragile hold on their island home.

Another critically endangered bird is the black paradise flycatcher. The male shakes his long tail feathers and calls in an attempt to attract a mate, but the female flycatcher is busy with other things. She is looking for insects and collecting spiders' webs. The spider's web silk is a strong nest-building material. She uses the sticky silk to help bind the nest into a neat cup.

The Seychelles blue pigeon is another island original. It feeds voraciously on fruit, which it swallows whole.

The tourists are only the latest in a long list of new arrivals. Outsiders have always come to these shores, joining the original descendants of Gondwana. Aerial migrants fly thousands of miles to congregate in large seabird colonies, while below the land is crawling with lizards.

Granite islands like this one have as many as one hundred thousand skinks, some say the highest density of lizards anywhere in the world.

These ground-dwelling reptiles can't fly and they don't swim but they can hitch a ride. Rafting skinks travel on all kinds of flotsam. A log or a tangled mat of vegetation makes a seaworthy craft.

Now ashore in a new land, the first task for a hungry skink is to find a meal. The most tempting delicacies are beyond reach until a coconut delivers a spider hors d'oeuvre. But skinks would never have thrived if they had to depend on such an unreliable menu. A nesting colony with hundreds of thousands of seabirds is a waiting banquet. The skinks would be much scarcer without the seabird colonies.

Noddy terns are another successful island colonist. They spend most of their lives on the wing, but at breeding time they must to return to land. Their sea legs are ill-suited for a narrow perch, and courtship gets off to a wobbly start. The broad branches of the pisonia tree are prime real estate for nesting, and the pisonia's big, floppy leaves are prized for home-building. On a small rocky island with few trees, these leaves are precious and often stolen.

In any case, seafaring noddies don't find nest construction very easy. A combination of shoddy nests and general clumsiness on land leads to accidents. For skinks, this is truly manna from heaven. Even when eggs make it through hatching, the chicks are ill-equipped for life in the trees. Many fall out of the nest before they can fly. And the skinks await eagerly any mishaps.

For the noddies that do survive, their hardships are not over yet. Twice a year the pisonia tree exacts a harsh toll for its services. In return for providing a home and nesting materials, the tree enlists the noddies as seed carriers. The seeds ripen with sticky hooks that attach themselves to passersby. The dangling branches are traps for unwary birds. When caught, some struggle out to sea. Now they become reluctant couriers, helping the pisonia tree to spread its seed to new islands.

Crippled by the load, other noddies are grounded for good. Feathers entangled, they fight for survival. In a final twist of fate the bird carcasses decompose, fertilizing the thin soil in which the trees grow.

Other victims, like this sooty tern, instinctively head for the sea in a desperate attempt to clean themselves. Waterlogged and unable to fly, this unlucky tern's fate is sealed. The casualties attract a nearby army of ghost crabs that patrol the beach. This solitary crab avoids the feeding frenzy and sneaks away with the catch, hiding it in a burrow.

The vast expanse of ocean is no barrier for some intrepid travelers. The day gecko is one such hardy voyager. Occasionally, geckos lay their eggs in driftwood. These makeshift rafts float out to sea, carrying the next generation of geckos into the unknown.

Beneath the waves lurks an underwater giant—the largest fish in the world—the rare whale shark. Up to forty feet long, this leviathan feeds on the tiniest of marine life, plankton. It sucks in large mouthfuls of seawater filtering the plankton out through a sieving system in its gills.

Closer to shore, the hawksbill turtle forages for food in the reef. It breaks apart the coral looking for sponges, and crushes the larger pieces with its hawk-like beak.

Parrotfish also come armed with a bony beak. These large fish must feed constantly during the day. They graze directly on the reef itself. Chipping off fragments of the coral, they feed on the nutritious algae, which covers the reef. These bite marks are the parrotfish's signature. The digested remains come out as a trail of fine white sand.

This coral sand turns out to be a vital ingredient in building new islands around the Seychelles. Sand and coral debris are washed against the reef by storms and tides over thousands of years. Eventually, the sand accumulates on top of the reef to form a brand new island. These small, sandy coral islands barely rise above sea level and lie in stark contrast to the ancient granite fragments of Gondwana. These younger islands begin devoid of life. Everything on them today is a relatively recent arrival.

The durable, waterproof shell of the gecko's eggs protects the precious cargo through the rigors of an ocean journey. Once hatched, the baby doesn't need to feed straight away. The young gecko has a store of yolk inside its stomach, which will keep it going until it reaches the safety of a palm tree. The geckos are tiny and vulnerable, but luckily sandy coral islands have few threatening predators. True masters of island colonization, it would be no surprise to find a gecko on every palm on every tropical island.

The seafaring geckos are joined on these coral islands by countless airborne migrants. More than a million sooty terns land on these beaches at the start of the breeding season. They stay only long enough find a mate and raise their young. It's a risky proposition since they lay their eggs on open ground within easy reach of predators. Fortunately, each pair of sooty terns has just one chick to feed and protect. The birds band together to form a communal nursery.

While there is safety in numbers, the defenders on the fringes of the colony need to be vigilant. A hungry egret stalks the perimeter looking for a wayward chick. The sooty parent jumps to the defense of its chick, despite the intruder's size. One attack is thwarted, but the egret is a persistent foe. Luckily, few egrets stray this far out of the way.

A common sight on most tropical islands, fairy terns are another champion colonizer. These blue-beaked birds are nicknamed "love terns." Unlike the other terns here, these affectionate birds breed year round. They live in the trees as devoted couples rather than congregating in large colonies on the shore. And they often mate for life.

Brooding is a reproductive high wire act. Fairy terns don't bother with nest building. They lay their eggs in almost any nook, no matter how precarious. But when the trade winds start to blow, their balancing act turns into a life and death struggle. The parent has no choice but to hang on.

Strong forces are constantly at work, reshaping and transforming the natural order. Beneath the waves, volcanic eruptions give birth to new mountains, which rise up from the sea floor. They provide a foundation upon which coral reefs grow. Over the centuries, the living reefs build up, layer upon coral layer, and eventually form new islands, which encircle the now extinct volcano. In the center, a shallow lagoon is left behind. This unique process of island formation creates a type of island known as an atoll, and the Seychelles is home to the world's most spectacular.

When Arab traders first came across this coral atoll they called it "Aldabra"—"the Green." Some say that the shallow turquoise waters of the central lagoon reflect in the clouds overhead and create a luminescent glow that can be seen from miles away. Aldabra is the largest raised coral atoll, 20 miles long with a central lagoon big enough to be called a sea. Twice a day the tide rushes in through narrow channels, flooding the lagoon with a fresh supply of seawater. What was once living coral is now fossilized, bleached and battered rock that the tides have sculpted into strange shapes. These low-lying islands have been submerged and exposed many times over their long history.

Among the colonizers of this jagged coral skeleton are some unexpected creatures. This lumbering giant is a rare survivor from the reign of the dinosaurs. Aldabra is home to the largest population of giant tortoises in the world. There are more than 100,000. That's seven times as many as on the Galapagos Islands, the only other surviving population.

Once widespread across the islands of the Indian Ocean, the first giant tortoise to arrive on Aldabra was probably swept off a beach hundreds of miles away. Cold-blooded and naturally buoyant, it can survive at sea for weeks at a time without food or fresh water. It's possible that just one castaway could have been enough to populate the island. Females can store sperm for up to nine months. So a single, fertilized female could have started a dynasty all by herself.

Crab plovers migrate in the hundreds to feed in the lagoon during their wintertime visit to Aldabra.

Over many generations, some birds have become prisoners of the island, like this flightless Aldabran rail. Its ancestors must have flown here once, but with no predators and little competition, the rail has lost the power of flight. Grounded now it can't leave.

Occasionally, the cautious tortoise indulges in a moment of high adventure. One false step and it's over. An overturned tortoise is a dead tortoise.

Lacking teeth, the tortoise swallows its food without chewing.

Tortoise romance can be a tricky business. The underside of the male tortoise's shell has a hollowed out shape to ease the perilous ascent into position. Despite all their hard work, only one in fifty couplings succeed.

When a young hatchling finally emerges, it's in constant danger of being eaten by predators or squashed by a parent. Growing from this...into this...can take a further quarter of a century. But if all goes well, a tortoise may reach as much as 140 years of age.

The short grasses here, known as "tortoise turf," have adapted to the constant grazing. With seeds near the bottom rather than the top of the blade, the grasses have managed to survive.

Tortoises feed during the cool hours of the early morning. By noon, it is tortoise rush hour and they move into high gear. Unable to regulate their own body temperatures, these large reptiles must head for the shade. There is a mid-day jam for cool spots under the trees. With the scorching sun, overheating is their greatest danger.

Apart from finding enough shade and fresh water, tortoises have little to worry about. Finally protected from man, the adults have no predators to disturb their rest. Sleeping with their necks extended is a good way to cool down. As they doze off, a burst of activity begins around them.

Hermit crabs take the opportunity to collect a fresh consignment of tortoise dung. Here nothing goes to waste.

The abbots gecko joins the noon gathering. It hopes to catch one of the insects swarming nearby. Unable to blink, the gecko uses its tongue to clean off its eyes.

Out in the midday sun, it's low tide in the central lagoon. Many come to feed in Aldabra's rich waters that teem with life, including the black-tipped reef shark. The shallow sea makes hunting easy.

Soon the tide turns and the lagoon fills again.

The clean-up crews on Aldabra are the many varieties of crabs that inhabit the island. These robber crabs are scavengers on the lookout for tortoise eggs and hatchlings. The female land crab carries a clutch of eggs on her belly that will soon hatch into larvae. She heads for the ocean to release them in time. Nothing distracts the mother crab from her task.

As night falls, the beach begins to crawl with activity. Robber crabs come in two shades, red or blue, and they can grow up to three feet across.

This giant hermit crab has given up hiding in shells. Besides, there are none large enough for it to inhabit. They are also known as coconut crabs after their favorite food. Powerful claws help them to crack open the hard outer shell of the coconut. Coconut envy can lead to all-out combat.

Undeterred, the female land crab ignores this tournament of jousting giants. She is on a more important assignment. The larvae are now hatching. They need the ocean to move on to their next stage of life. But, for the mother, this can be a hazardous duty. She releases the eggs by lowering one side of her shell and jiggling her body in the waves. This life-giving dance can be risky. Some mother crabs drown in the surf.

The female tortoise lays her eggs at night to keep cool. The digging goes slowly, one leg at a time. It can take up to eight hours of patient work to prepare her nest. The egg chamber is now ready and it is time to lay the eggs. A single female may lay a dozen or more.

It is the start of a new generation that will differ little from its ancestors going back 200 million years. Sheltered by a simple island existence, evolution has left these animals behind. Here, the tortoise has been protected from the march of time.

The islands of the Seychelles remain a world apart, where relics from Gondwana survive in safe seclusion, and where species, separated from their ancestors for generations, grow into new and exotic forms. These islands remain fragile and priceless sanctuaries. It is not the original Garden of Eden, but the Seychelles is a rare living paradise on Earth.

How did the Seychelles wind up a thousand miles out in the Indian Ocean? Track this archipelago from its birth in the heart of Gondwana to where it might be 50 million years from now at or America Online, keyword PBS.

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Scientific achievement is fueled by the simple desire to make things clear. Sprint PCS is proud to support NOVA.

This program is funded in part by the Northwestern Mutual Foundation. Some people already know Northwestern Mutual can help plan for your children's education. Are you there yet? Northwestern Mutual Financial Network.

And by the Corporation for Public Broadcasting, and by contributions to your PBS station from viewers like you. Thank you.

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Garden of Eden

Edited by
David McCormick
Stephanie Munroe

Produced by
Miles Barton
Marti Louw

Narrated by
Peter Thomas

Gavin Thurston

David Mitcham
Ray Loring

Neoscape, Inc.

Script Writer for BBC
Sophie Cooper

Unit Manager for BBC
Christina Hamilton

Production Manager for BBC
Jenni Collie

Assistant Editors
Christina Hunt
Rob Todd

Online Editor
Fernando Guerreiro

Brian Lovery

Scientific Advisors
Lindsay ChongSeng
Justin Gerlach
Adrian Skerrett
Dr. Millard Coffin

Production Assistants
Jennifer Callahan
Adam White

Special Thanks
Aride Island Nature Reserve
Basil Beaudouin
Michael Betts
Birdlife Seychelles
Atterville Cedras
Cambridge University, Department of Earth Sciences
Pat Mathiot
Ministry of Environment, Seychelles
Gérard Rocamora
David Rowat
Seychelles Islands Foundation
The University of Texas Institute for Geophysics

NOVA Series Graphics
National Ministry of Design

NOVA Theme
Mason Daring
Martin Brody
Michael Whalen

Sound Editor/Audio Mix
John Jenkins

Post Production Online Editor
Mark Steele

Closed Captioning
The Caption Center

Production Secretaries
Queene Coyne
Linda Callahan

Diane Buxton
Katie Kemple

Senior Researcher
Ethan Herberman

Unit Managers
Jessica Maher
Sharon Winsett

Nancy Marshall

Legal Counsel
Susan Rosen Shishko

Business Manager
Laurie Cahalane

Post Production Assistant
Lila White Gardella

Assistant Editor Post Production
Regina O'Toole

Associate Producer Post Production
Judy Bourg

Post Production Editor
Rebecca Nieto

Production Manager Post Production
Lisa D'Angelo

Senior Science Editor
Evan Hadingham

Senior Producer Coproductions and Acquisitions
Melanie Wallace

Managing Director
Alan Ritsko

Executive Producer
Paula S. Apsell

A BBC/WGBH Boston Co-Production
© 2000 BBC
Additional Program Material © 2000 WGBH Educational Foundation
All rights reserved


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