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Ap Bio Research Paper

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Topic 1

Earth’s vegetation and animal life are all part of an intricate “web” of essential relations in which both cannot survive without the other. According to Campbell’s Biology textbook, The transfer of food energy up the trophic levels is referred to as a food chain. This chain usually begins with plants, (primary producers), then herbivores, (primary consumers), to carnivores (secondary, tertiary and quaternary consumers), and finally decomposers. When one part of the chain is low in population, the species above it are likely to be negatively affected and will likely drop in population as well. In order to show how delicate this web is, and how human activity has affected this system, Carson describes a small food chain in which sagebrush …show more content…

According to Silent Spring, the United States Office of Plant Introduction has introduced about 200,000 species of plants from around the world, and almost half of the 180 major insect enemies of plants are accidental imports. According to Campbell’s Biology Textbook, these imported animals are known as invasive species, organisms that become established outside their native range. Carson states that often when a species is brought to an area they are not native to, the lack of natural enemies causes the species to become dominant and extremely abundant. These invasions are likely to be permanent, however as a way to “buy time” humans have turned to quarantine and massive chemical campaigns, instead of trying to prevent new invasions. As Carson continuously stresses chemical use can have unwanted consequences and she urges people to use the basic knowledge of animal populations and their relations to their surroundings and other species to prevent them from becoming overly dominate. For example, according to Campbell’s textbook, higher diversity communities are more often resistant to invasive species because the species is less likely to dominate over the native species. This was proven by scientists working in Long Island Sounds off the Coast of Connecticut created communities of different diversity consisting of sessile marine invertebrates, and examined how vulnerable the experimental communities were to an invasive species: the exontic tunicate. They found the tunicate was four times more likely to survive in lower diversity communities than higher diversity communities. It was concluded the diverse communities captured more of the resources available, leaving fewer resources for the invader. It is firmly believed by Carson that people should do much more simple research before transferring a foreign species to a new habitat to not only prevent a

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