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Tatiana Turkin Pd.3.

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Presentation on theme: "Tatiana Turkin Pd.3."— Presentation transcript:

1 Tatiana Turkin Pd.3

2 Chapter 1: A Fable For Tomorrow
The book begins by describing a pristine ecosystem in which farms are prosperous, the seasons change beautifully, magnificent plants and flowers bloom, and birds and other species are abundant. This sets the scene of a utopic natural community. Then, an epidemic strikes the town that kills all the organisms that inhabit it and render it barren and “silent.” The only hint of the source of the catastrophe is a white granular powder. It is explained that this town is fictional, yet is based on the disastrous occurrences of real places. The chapters ends by saying the book will explain why these misfortunes are happening.

3 Chapter 3: Elixirs of Death
The author, Rachel Carson, describes common chemical poisons, their origins/uses, and their harmful effects. She explains that synthetic pesticides originated as chemicals in chemical warfare during World War II until scientists discovered they could kill insects as well. In the short span of 20 years, the use of pesticides have saturated all organisms on earth, not just insects. Some examples of pesticides she gives are arsenic, DDT, Chlordane, Dieldrin, Aldrin, Endrin and different organic phospates. Each differ in effects and toxicity, but they all change the body’s processes like destroying enzymes, blocking oxidation, killing organs, and causing cancer.

4 Chapter 4: Surface Waters & Underground Seas
Carson calls water our greatest natural resource and explains how its supply for human use is limited. Pollutants such as radioactive wastes, nuclear explosions, domestic waste, and chemical sprays are contaminating our drinking water more and more. Chemicals dissolved in water are hard to detect and be broken down. Some chemicals are deliberately put in water to kill fish or unwanted organisms, some seep from forest spraying, and some are residue from extreme farmland spraying. Adding pesticides to any water affects all water because of the recycling in the water cycle. Carson gives examples of water pollution around the U.S. that had detrimental effects on people and nature.

5 Chapter 6: Earth’s Green Mantle
This chapter is about our necessity for plants and the way we treat them. Carson talks about how we reckless destroy plants if they’re considered harmful or in the way which in turn disturbs interconnections within an ecosystem. These disturbances have far- reaching consequences that affect everything in an environment. She gives examples of needless weed killing such as the sagebrush land of the West. People sought to eliminate the sagebrush and replace it with grass without realizing the sagebrush would protect the grass by retaining moisture in the extremely dry climate. This shows that what’s considered a “weed” is actually beneficial and shouldn’t be chemically destroyed.

6 Chapter 8: And No Birds Sing
Carson discusses the increasing disappearance of birds in the U.S. in this chapter. Many birds are directly affected by pesticides because their habitats and food is poisoned. Birds also can starve because of the chemical massacre of their main prey, insects. The irony is birds themselves play a crucial role in pest control by maintaining a healthy insect population. Therefore, when the birds are gone, insects populations rise and become more harmful to plants and other parts of the ecosystem. Using pesticides to kill “pesty” insects upsets a crucial part of the food web and in turn creates the opposite of the intended result: more bugs.

7 Chapter 16: The Rumblings of an Avalanche
The most ironic part of the pesticide movement is that over time, insects have become resistant to the chemicals become harder to kill. This exemplifies Darwin’ theory of survival of the fittest and was dreadfully expected. This worries scientists because this means resistant disease carrying insects are still a threat. Some examples used are body lice carrying typhus, rat fleas carrying plague, tsetse flies carrying African sleeping sickness, ticks carrying fevers, and mosquitos carrying yellow fever, malaria, and encephalitis.

8 Chapter 17: The Other Road
The final chapter of the book states two answers that society has regarding the problem of insect control. First, chemical poisons have proven to be costly, ineffective, and extremely/lastingly dangerous. Second, biological controls have proven to be cheap, effective, and safe for humans and other animals and insects. Biological controls also cooperate with nature instead of working against it. Biological controls were introduced long before chemical insecticides, but when the chemicals hit the market it became a scientific fad to try them out. One of the most successful new biological controls is the sterilizations of insects, pioneered by Dr. Edward Knipling.


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