GENETICS

Genetics



Genetics

Introduction

Endangered species are animals or plants that are soon to die out. This means that once they become extinct, they will never be seen on Earth again. Many animals and plants become endangered or extinct each year. Recently, however, the rate of them dying out increased dramatically. It is estimated that 27,000 species become extinct each year, about 3 an hour. Since 1996, scientists calculated that 124 types of amphibians, 1,108 types of birds, 734 types of fish, 1,096 types of mammals, and 253 types of reptiles became endangered. This statistics also apply to plants.

There are many reasons that can cause a species of animals or plants to become endangered, or even extinct. First of all, the human population has exploded since the last few decades. To accommodate the oversized human population more and more lands are taken away from these animals or plants(Robertson, 2007). The natural habitats are snatched away from these species, leaving them only a small portion of the land, which they once roamed freely. With the little amount of land these animals or plants have, the food source become scarce. They have to fight among themselves in order to remain alive. They also don't have enough room to live. Sometimes animals or plants don't adapt to the limited space they now have, and die.

Animals and plants also become endangered because of the chemicals people use. When people use pesticides to kill off insects and other pests, they are also endangering the lives of other species around them. These chemicals may get into the river or other water sources. Fish live in the water. They consume it(Stolzenburg, 2006). Then when birds come along and prey on them, these birds are also contaminated with the dangerous chemicals. The eagle, our national symbol, also experienced this deadly scenario. DDT, a type of pesticide, caused the eggshells to become fragile. When the female tries to incubate, sit on them, the shells just collapse. The population of eagles had gone down rapidly with the use of DDT. When scientists and environmentalists learn of this danger, they quickly ban the use of DDT. Now the eagle population is rebuilding.

Hunting and trading are other reasons that threaten the lives of many innocent living creatures on Earth. Thousands of years, people kill animals or plants just for the fun of it, or for trading. Many of them do it illegally, or poaching. People kill animals for their fur, oil, body parts, and many other things in order to fatten their wallet(Wiese, 206). These things then, are turned into fur coat, cosmetics, perfume, oil for lamps, and traditional medicines. The tiger has been overly hunted for its bone because some people think that the bone has some magical healing power. Now the worldwide population of tiger is not doing so well. Some exotic birds are dying out because of trading. They get shipped around the world. While they are being sent, some die. Others don't adjust to the new environment also die(Sukumar, ...