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Evolution of Biodiversity
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Diversity of Species Biodiversity a. ecosystem diversity b. species diversity c. genetic diversity
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Species Richness a. number of species in a given area b. used to give approx. sense of biodiveristy in a given area Species Evenness a. relative proportions of individuals within the different species b. low and high evenness
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Phylogeny a. evolutionary history of organisms b. shows relationships among species c. phylogenetic tree http://www.macalester.edu/~montgomery/GrayWolfExtra.html
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Charles Darwin’s Theory of Evolution Galapagos Islands a. Darwin’s finches
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Origin of Species by Natural Selection – by Charles Darwin Evolution – concept that species have changed over time a. microevolution vs. macroevolution
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Natural Selection “organisms best suited to their environment reproduce more successfully than other organisms” * Adaptation * *selection conditions change as the demands of the environment change *if change is too extreme and organism can’t change, they become extinct or die
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Genetic Drift a. change in genetic composition of a population over time as a result of random event b. biggest impact on SMALL populations
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Bottleneck Effect a. population bottleneck b. reduction in genetic diversity of a population caused by a reduction in its size c. low genetic variation = problems
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Speciation “two species arise from one” Geographic isolation and reproductive isolation
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Pace of Evolution Rate of environmental change Genetic variation Artificial selection Genetically modified organisms through genetic engineering
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Ecological Niches and Species Distributions Niche - “way of life” a. range of tolerance b. fundamental v. realized niche c. niche generalists v. niche specialists
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Extinction 3 reasons a. geographic location b. space c. adaptation Fossil record Mass extinctions a. 5 global b. possible 6 th – human causes (dramatic and sudden)
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