Pg 8 ECOLOGY Ecology is a relatively new science, in the recently past, fascinated only intellectuals and scientists.Nowadays many of the mayor problems that science must face are: pollution, overpopulation, hunger, deforestation, desertification, the wrong use of resources. Ecology is therefore a branch of science that studies the relationships between living organisms (plants, animals, people) the inorganic and organic environment and the balances between these relationships. An ecological community, living and evolving in community various species of organisms: they form the ecosystem. Indusstrial and the progess are the two causes of alteration the ecosystem; they have comported all successive problems. The alteration of the balance of an ecosystem can have catastrophic effects on the environment such as pollution, desertification, deforestation,extinction of animal and plant species. THE ALTERATION OF ECOSYSTEMS It all started with the Industrial Revolution, when factories began to fill the atmosphere with noxious gases and fumes and dump toxic waste into the seas, rivers and lakes, polluting the air and the water. Nowadays factories and cars keep on fouling the word around us, damaging people's health, wildlife and the environment. Moreover, forests have been cut down or burnt and lakes and rivers poisoned with pesticides. For many years no one paid much attention to these problems until the earth itself, our home, began to send loud and clear messages. They spoke of: air, water, land, acoustic pollution the extinction of wild animals and plants deforestation desertification overpopulation and world hunger. In the last 30 years scientists and people have realized that much of the planet is in danger; it is a disaster which is going on around us and which can be experienced by everybody through the changing of the earth's climate and the crisis of the environment. The most evident symtoms of this crisis are: acid rain the greenhouse effect the hole in the ozone layer the actual solution is really very simple: either we stop killing the earth or we will kill ourseves.