Giant Pandas

In August of 1999, the birth of Hua Mei [hwah may] at the San Diego Zoo was reason for celebration around the world. Why all the excitement? Scientists believe there are just 1,000 giant pandas left in the wild and about 120 in captivity. Bamboo, the sole food of giant pandas in the wild, is scarce. The destruction of the bamboo forests in China has caused the near-extinction of the giant panda. Without intervention, the only giant pandas left will be those born in zoos.

What Is Extinction?

Plants and animals on our planet have become extinct since the earth began. Some scientists believe that extinction is a natural process. As one species disappears, another replaces it. This development takes place over millions of years. It creates a natural biological variety of living things. For all the species that we know today, there are thousands of others that lived millions of years ago.

These extinct species are all gone. Paleontologists know this because they study the fossil record of plants and animals. When a fossil no longer appears, the scientists assume this species became extinct. No extinct animal or plant has ever reappeared. During the history of the earth, masses of animals and plants have become extinct within a short period of time. These mass extinctions have happened five times. Today we are in the sixth period of mass extinction. What caused this to happen in the past? Why is it happening today?

Ecosystems

All living things, plants or animals, depend on other living things to stay alive. Every living thing from onecelled amoebae to giant dinosaurs is part of an ecosystem (a group of living things in an environment). Over millions of years, living things adapt to their environment and become part of ecosystems. When something disrupts the ecosystem, the living thing does one of two things: It adapts or becomes extinct. When one animal or plant dies, other animals that depend on it for food can die, too. When the ecosystem is disrupted, this leads to the extinction of some species within it.