Biology 2483A Lecture Notes - Lecture 22: Overfishing, Cichlid, Unionoida
8 Dec 2017
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Document Summary
Humans have always had a large impact on other species. Bones found on pacific islands reveal the prehistoric extinction of up to 8,000 species of birds following colonization by polynesians. Some entire guilds went extinct, which must have caused large community changes. For mammals and birds, the background rate is 1 species every 200 years. Species life span of 1 to 10 million years. For mammals and birds, the rate is 1 species every 1 year. Overall, extinction rates in the 20th century were 100 to 1,000 times higher than the background rate. Try to remove some model assumptions--> assumption of species area relationship. Species in a given area just from a sample (trying to remove this!) Look at relationship at extinction rates with time, and recent times. Something happens in 1800-1900 and there is a distinct rise. Overall extinction rates in the 20th century were 100 to 1,000 times higher than the background rate.
