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Extinction

The vast numbers of animals that once covered the earth have rapidly disappeared as the population of man has increased. When all of one species of an organism is gone, it is extinct. Extinction is irreversible. Man has directly or indirectly caused many animals and plants to become extinct. People have hunted animals for food, feathers, furs, or just for sport, sometimes killing all of one kind. Pollutants and poisons that we add to the air, land, and water kill organisms. When people move into a new area, they often bring their familiar animals with them, but sometimes these animals replace the native animals and plants that have been living there. By enclosing land for farming, humans have reduced food sources available to herbivores and have disrupted migration routes that were important for the survival of wild animals. 

When people change the habitat where an animal lives, they take away its food and shelter.

Unless the animal can survive with the changes or find another home, it will die. The gorilla makes its home in the tropical rain forest and montane forest. It cannot survive where there are no trees. Many trees in the forests are being cut down for timber or burned to clear land for crops. In this example, though the gorilla is not being directly killed by humans; its food and shelter are being removed. As the area of Africa covered by forest shrinks in size, so does the range of the gorilla and its numbers.

Some types of plants and animals are more likely to become extinct than others: these include animals that man considers dangerous (lions attack people and livestock), those that compete with man for resources (leopards kill smaller domestic animals), or those that have something that man values (the ivory tusks of an elephant). One animal or plant that becomes extinct affects all the other organisms around it. What would happen to animals that preyed upon it?

Africa has more large animals than anywhere else in the world; it is the last continent where great herds of large mammals can still be found. During the Ice Ages, large herds of hoofed animals were found all over the world. Scientists are not sure what happened to these mammals on the other continents. One theory suggests that in addition to unfavorable climatic changes, early humans were responsible for over-hunting them. As humans slowly evolved in Africa, the animals adapted to deal with this new predator. When humans moved to new continents with their weapons, the animals were not able to quickly adapt to their presence and were hunted to extinction. Our influence on nature and extinction may go back further than we realize.

Humans are part of the natural world, yet of all the life on earth, humanity alone has the greatest ability to rapidly change and destroy the face of the earth. Within the last few hundred years, Westerners came to Africa and brought with them guns and other new weapons, for which the animals of Africa have no defense.

Since the end of the last Ice Age, the climate of Africa has become drier (caused in part by the introduction of domestic animals from abroad, overgrazing, and poor land management) and has turned more than a quarter of the land to desert. The desert cannot support as many animals as the savanna or rain forest. Because of these climatic changes and man's actions, many African animals are now found primarily in parks where they are protected. These animals are still in danger, and unless more help is provided, they will soon be gone. Extinction is forever.

 

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