I'm Shirley Griffith. And I'm Steve Ember with EXPLORATIONS in VOA Special English.
Today, we tell about the Galapagos Islands in the Pacific Ocean and the unusual creatures that live there.The 19 islands that make up the Galapagos lie along the equator 1,000 kilometers west of Ecuador. The islands are named for the giant tortoises that live there. Galapagos has been called "a living museum and showcase of evolution." The animals on the islands influenced British nature scientist Charles Darwin's ideas about evolution by natural selection.
In 1978, the islands were the first place named to the World Heritage List by the United Nations Educational, Scientific and Cultural Organization. Recently, however, UNESCO added the islands to its World Heritage in Danger list. The main reason is the increase in the number of visitors to the islands
The World Heritage Committee said increased tourism, immigration and invasive species threaten the animals of the Galapagos. Many of these animals are found nowhere else in the world. The committee noted that the number of days spent by passengers on ships in the area has increased by 150% in the last 14 years. The number of visitors each year has doubled in five years and grows almost 12% every year. More than 145,000 people visited the islands last year.
The islands' increased tourism has brought thousands of workers from Ecuador to seek jobs. Some workers have brought non-native animals like dogs, cats, pigs and goats. These animals compete for food with the islands' native animals. Some also attack the native animals. Ecuadorian President Rafael Corea declared the islands at risk in April. He has promised more restrictions on tourism and population.Mystery always has been part of the Galapagos. In 1535, a ship carrying the Roman Catholic Bishop of Panama came upon the Galapagos accidentally. Tomas de Berlanga named the Galapagos group the Enchanted Isles. He was surprised to see land turtles that weighed more than 200 kilograms and were more than one meter long. He said they were so large each could carry a man on its back. Bishop Berlanga also noted the unusual soil of the islands. He suggested that one island was so rocky it seemed like stones had rained from the sky.
Ecuador took official possession of the islands in 1832. The British nature scientist Charles Darwin is mainly responsible for the fame of the Galapagos Islands. He visited the islands in 1835. He collected plants and animals from several islands. After many years of research, he wrote the book "The Origin of Species" in 1859. He developed the theory of evolution that life on Earth developed through the process of natural selection
The book changed the way people think about how living things developed and became different over time. Darwin said the Galapagos brought people near "to that great fact -- that mystery of mysteries -- the first appearance of new beings on earth".
One hundred years later, in 1959, the Ecuadorian government declared almost all of the islands a national park. The Charles Darwin Foundation was formed the same year to study and protect the plants and animals on the islands.More than 125 landmasses make up the Galapagos. But only 19 are large enough to be considered islands. Scientists have been wondering for years about the position of the Galapagos in the Pacific Ocean. Scientists used to think that the islands were connected to the South American mainland and floated out to sea slowly
Today, most scientists think the islands were always where they are now. But they think the islands once were a single landmass under water. Volcanic activity broke the large island into pieces that came to the surface of the sea over time.
But scientists wonder how animals arrived on Galapagos if the islands were always so far from the mainland. Scientists think most Galapagos plants and animals floated to the islands. When rivers flood in South America, small pieces of land flow into the ocean. These rafts can hold trees and bushes. The rafts also can hold small mammals and reptiles. The adult Galapagos tortoise clearly is too big for a trip hundreds of kilometers across the ocean. But, turtle eggs or baby turtles would be small enough to float to the islands.
The Galapagos Islands are home to many unusual birds, reptiles and small mammals. Some of the animals live nowhere else on Earth. The tortoise is the most famous Galapagos reptile. But the marine iguana is also unusual. It is the only iguana in the world that goes into the ocean. The marine iguana eats seaweed. It can dive at least 15 meters below the ocean surface. And it can stay down there for more than 30 minutes.
Several strange birds also live on the Galapagos. One of them is the only penguin that lives on the equator. Another is the frigate bird. It has loose skin on its throat that it can blow up into a huge red balloon-like structure. It does this to attract females that make observation flights over large groups of males.
The Galapagos also are noted for a bird that likes water better than land or air. The cormorant is able to fly in all the other places it lives around the world. But the Galapagos cormorant has extremely short wings. They cannot support flight. But they work well for swimming.
The islands also have a large collection of small birds called Darwin's finches. Charles Darwin studied the finches carefully when he visited the Galapagos in 1835. He separated the birds by the shapes of their beaks. He discovered that finches that lived in different places and ate different foods had different shaped beaks.But the most famous animals on the Galapagos Islands are the thousands of giant tortoises. And the most famous of these is the one that scientists call Lonesome George because he is the last of his kind. He has been called the rarest creature on Earth. At one time, the islands were home to about 15 different kinds of land turtles. The largest island, Isabela, has five different kinds of tortoises. But, Lonesome George is not one of them. He comes from a smaller island called Pinta.
Scientists found George in 1971. Humans and non-native animals had caused much damage to the environment on his island. Some animals and plants had disappeared. Lonesome George was the only tortoise found on Pinta.
Scientists took the tortoise to the Charles Darwin Research Center on Santa Cruz Island. They wanted to help him find a female tortoise for mating to produce baby tortoises. The scientists had been successful in similar efforts for thousands of other tortoises
The researchers placed George in the same living area as females from the nearby island of Isabela. Scientists thought George would be more closely related to the females from Isabela than to other Galapagos tortoises. However, George has not been able to mate successfully with the female tortoises. No eggs have been produced.
Scientists have been studying the genetic material of tortoises on the islands and around the world. They have not found one with DNA like George's. However, earlier this year, scientists from Yale University in the United States made an important discovery. They identified a male tortoise on Isabela Island that is an offspring of a female from Isabela and a male from Pinta. That means this tortoise has half his genes in common with Lonesome George. Scientists believe there might be a female carrying Pinta genes that could be a mate for George.
However, another scientist has noted that even if such a female is found, George has shown little interest in mating with female tortoises. George is between 70 and 80 years old. But some tortoises live longer than 150 years. If Lonesome George fails to become a father, the Pinta Island tortoises will disappear when he dies.This program was written by Caty Weaver. It was produced by Mario Ritter. I'm Shirley Griffith. And I'm Steve Ember. Transcripts and archives of our shows are at voaspecialenglish.com. Join us again next week for EXPLORATIONS in VOA Special English.