BIO 103 Lecture Notes - Lecture 11: Population Pyramid
11 Apr 2017
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Document Summary
A possible crash: the cycle of growth beyond carrying capacity leads to population crashes and, sometimes, rebounds, easter island. The island is very isolated in the pacific. Island was once a tropical forest and supported 7000 people. They destroyed the forest and population crashed by 1775 to 700: demographic momentum = time lag between when humans reduce birth rates and when population growth begins to slow. Even while parents are reducing family size, their children grow and have children. Avoiding disaster: for humans, other factors also affect population growth rate, including: Income and women"s literacy: thus, social policies can have large impacts on human population growth, the question of how many people the earth can support is not just one of science, but of values and ethics. Quality of life: the american lifestyle is only supported by using resources from other countries, but global carrying capacity only provides enough food and water.
