James Bureman, age 14, of Florissant, Missouri, for his question:

Why are the Galapagos Islands so special?

The home of the earth's oldest animal should be rather special. Surely the home of the earth's only sea going lizard deserves special recognition. These are merely two of many one of a kind creatures that belong to the Galapagos Islands. However, this ocean archipelago also happens to be an operating demonstration of the story of life on our planet.

All the special biological features of the Galapagos Islands spring from special geographical features. The archipelago of 14 sizeable islands and many islets straddles the equator. It is a scattering of volcanic peaks in the deep Pacific, about 600 miles west of Ecuador. At the equator, one expects warm weather and dousings from tropical thunderheads. But through this part of the Pacific sweeps the cold Humboldt Current, bringing eternal streams of water up from the chilly seas of Antarctica. Many of the islands are in sight of each other. But they are separated by deep cool currents of swirling water and each island is an isolated world unto itself.

Around the shores of rough, rocky lava the climate is mild and very arid., The larger islands have ragged uplands where misty moisture provides for ferns and mosses, grassy valleys and forested slopes. There are no poisonous snakes and no mosquitos bearing malaria and other tropical diseases. The region is very healthy and the sudden changes in geographical environment encourage a vast variety of plants and animals. And it is these living things that make the Galapagos Islands a special paradise to biologists.

Here we find creatures that were separated from their ancestral families, maybe many millions of years ago. Most of them arrived there as castaways and lived a marooned existence, each on his isolated island. Birds arrived on storm winds and penguins were swept up from Antarctica. Reptiles and insects most likely arrived from the mainland on floating logs. Bats arrived and rats were left behind by visiting vessels. Each castaway had to cope with life as he found it. And in the 1800s, visiting scientists were astounded to find how well they had done.

A land loving lizard took to surfing, dining on seaweed and basking on the dark tidal rocks. The Galapagos iguana is the world's only marine lizard. The original finches multiplied and divided the food supplies between them. One group developed beaks suitable for eating seeds or prickly cactus. Others developed suitable beaks for catching bugs. One type took up woodpecking, though he had no long woodpecker tongue to scoop out his victims. So he learned to hold a twig in his beak and to use it to pry bugs and grubs from woody tree trunks. This fantastic finch is one of the world's rare tool using animals. But the rarest native is the giant Galapagos turtle. He may weigh almost half a ton and it takes him 12 full laborious hours to travel a mile. But this oldest of earth's animals may live to celebrate more than 200 birthdays.

These and many other features add up to make the Galapagos archipelago a very special place. The assorted species of plants and animals are related to families in faraway places. But the Galapagos species differ in small details from their distant kinfolk. Through countless generations of struggling to survive, nature has favored off spring with special features. Many of the lizards must have perished before a few Galapagos iguanas took to marine life, thrived there and handed on life to new generations. This natural sifting and sorting is demonstrated again and again throughout the isolated islands.