Where Did It All Begin?

1. Where Did It All Begin? Before there was any life on Earth, the world was a bleak and rocky globe with only shallow seas and a thin layer of gas. The earth was a very desolate and hostile place. This type of environment is called an inorganic state. Energy from the sun bombarded the surface of the Earth. In time, millions of years later, the sun produced chemical and physical changes on the Earth’s surface and this resulted in the first evidence of life.

2. In The Beginning The first living creatures on earth were formless, jelly-like blobs. These tiny creatures could collect life-giving energy from the Sun. They were also capable of reproduction which meant that they could continue to produce more living creatures. This generation of life formed the first community and established what is called the “zone of life”. Here the matter of the Earth was used to make living substance.

3. The Zone of Life Then, like now, living creatures needed certain things to live, grow, and reproduce. Water was one of the major elements. All living creatures depend on water for life to continue. Other essential elements include those gases and elements found in the air. And of course, the life giving energy of the Sun In addition to these essential elements, all life on Earth depends on green plants to live. Plants use sunlight to produce food which feeds animals. This process is called photosynthesis. Plants also provide oxygen. Most animals require oxygen for respiration.

4. Ecosystems During this time, living organism produced large numbers of a few kinds of living creatures. Soon plants and animals of all kinds evolved. Families or communities developed so that certain plants grew with other plants. Animals associated with the plants and with one another to form communities. These communities included forests, grasslands, deserts, dunes, bogs, rivers, and lakes. Soon the living community and their nonliving environment became inseparable, interrelated, and constantly interacted with one another. The living community and the nonliving environment is called an ecosystem.

5. Kinds of Ecosystems There are two kinds of ecosystems. Aquatic Ecosystems are those involving marine environments and freshwater environments on the lands. Terrestrial Ecosystems consist of forest, grasslands, deserts, and tundra. There are particular animals that thrive in each type of ecosystem.

6. What Is Pollution? Pollution is the result of adding substances or forms of energy to the environment at a rate that is faster than the environment can accommodate its disposal. Pollution has been a fact of life since groups of people first congregated and remained in one place for long periods of time. But pollution was not a serious problem as long as there was enough space available for each individual or group. With the establishment of communities, pollution became a problem. This occurred as early as ancient times. With the rise of technology, the spread of industrialization, and the increase in human population, pollution has become a universal problem.

7. Types of Pollution Pollutants are those elements responsible for pollution. They are classified according to the part of the environment they affect. Air Pollution is a result of substances being released into the air in large quantities. These substances include gases, finely divided solids, or finely dispersed liquid aerosols. Water Pollution is caused by the accumulation in oceans, lakes, streams, and ground water. The major causes of water pollution include sewage, industrial waste, garbage and refuse, and agricultural fertilizers such as pesticides and herbicides.

8. What is Pollution?? Water Pollution is caused by the accumulation in oceans, lakes, streams, and ground water. The major causes of water pollution include sewage, industrial waste, garbage and refuse, and agricultural fertilizers such as pesticides and herbicides. Land Pollution is caused by the deposition on land of solid waste that cannot be broken down completely or in some cases cannot be broken down at all. These include such as cans, bottles, plastic containers, paper, and used cars.

9. Endangered Species Resources

10. Just For Fun!! Classify the images below as either air, water or land pollution. You will be able to check your answers once you have completed the slide show.