Environmental Science Exam 3

Environmental Science Exam 3 - 27 In two or three...

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27. In two or three well-developed paragraphs, summarize how the reproductive behavior of individuals can affect the growth rate of their population. If the population stops reproducing, the population will start to decline. If the population changes how often they reproduce, the population will change. If the population changes its opinions on reproduction, the population will change. Declining birth rates also lead to reduced population growth. Humans make birth control choices, but other animals also do this. For example: fruit flies living in crowded conditions lay fewer eggs and laboratory rats in a small areas soon reach a stable population size even if more than enough food is available. Some mammals and birds limit the number of possible parents by establishing breeding territories where mating pairs occupy an area only big enough to supply their needs and those of its offspring. Social rules among humans, like the proper age of marriage and good family size also influence on birth rates. Individuals are born and die and populations grow and decrease. The size of a population is the result of births and deaths, and immigration and emigration. The rate at which individuals enter the population (births and immigration) and individuals leave (deaths and emigration) will determine whether the population is growing, shrinking, or is stable, and if it is changing, how fast. 28. In two or three well-developed paragraphs, describe how the size and growth rate of the human population has changed in the last 200 years. After the start of the Industrial Revolution in the 18th century, living standards rose and famines and epidemics decreased in some areas. Population growth increased. The population climbed to about 760 million in 1750 and reached 1 billion around 1800. The growth of the last 200 years appears explosive
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This note was uploaded on 08/18/2011 for the course SCIENCE 101 taught by Professor Greene during the Spring '10 term at Keystone.

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Environmental Science Exam 3 - 27 In two or three...

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