SNES 1101 Chapter Notes - Chapter 9: Bioaccumulation, Biomagnification, Arboretum
17 Nov 2016
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Chapter 9 - sustaining biodiversity: the species approach. All content in this file is based on - g. tyler miller, scott e. spoolman. All high quality pictures in this file are posted separately to the community. Background extinction the low level of species extinction that is considered normal. A percentage or number of species that go extinct within a certain time period. Estimated background extinction = one extinction per million species per year. Mass extinction the extinction of many species in a relatively short period of geologic time. There have been 5 mass extinctions (50% - 99%) Occurs when a species is no longer in an area it once inhabited but is still found elsewhere in the world. Occurs when so few members of a species are left that it can no longer play its ecological roles in the biological communities where it is found.
