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Published byJemima Horton Modified over 9 years ago
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Ecosystems, Populations, and biodiversity SCI 7724
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Case Study: Costa Rica Cloud forest
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What is evolution, really?
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Natural selection
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Natural selection works on POPULATIONS
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Evolution can generate biodiversity
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What is speciation and how does it happen?
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Population separation Allopatric speciation
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Sympatric speciation
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Phylogenetic trees
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Mass extinction events Most extinction occurs gradually– background extinction rate Mass extinctions can wipe out 50-95% of biodiversity 65 mya- K-T event 250 mya- 75-95% of species extinct- volcano?
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The sixth mass extinction http://www.well.com/~davidu/extinction.html
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Levels of ecological organization Biosphere Ecosystem Community Population Individual
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Niches What’s so important about niches?
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Population size How is it calculated/estimated? Why is it important?
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Population density How is it calculated/estimated? Why is it important?
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Population distribution How is it calculated/estimated? Why is it important?
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Sex ratios and age structure Why does it matter?
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How populations change over time
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Limiting factors and carrying capacity
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R- and K-selected species
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Conservation of Biodiversity Cloud forest
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Interpreting graphs
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