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- EnvSci 10: Biodiversity
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•Populations with high genetic diversity are better able to respond to environmental change than with lower genetic diversity.
Biodiversity: The diversity of life forms in an environment.
•Scientists have identified and cataloged approximately 2 million species on Earth. Estimates of the total number of species on Earth range between 5 million and 100 million, with the most common estimate at 10 million.
•The average rate at which species go extinct over the long term, referred to as the background extinction rate, is very slow: about one species in a million every year. (With 2 million identified = two species per year).•Under conditions of environmental change or biological stress, species may go extinct faster than new ones evolve. Some scientists estimate that more than 10,000 species are currently going extinct each year—5,000 times the background rate of extinction!(Friedland page 5)Biodiversity hotspots. Conservation International has identified 34 biodiversity hotspots that have at least 1,500 endemic plant species and a loss of at least 70 percent of all vegetation. (Friedland p.144)