lecture_18_macroevolution_2_SW

lecture_18_macroevolution_2_SW - Why do some groups have...

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Why do some groups have many more species than others? 1) Random chance: a constant rate of speciation and extinction can still generate very asymmetric phylogenies and diversification patterns- statistical tests help rule this out 30 species 3500 species
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Why do some groups have many more species than others? 2) Empty niche hypothesis (release from competition)- adaptive radiations
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Why do some groups have many more species than others? 2) Empty niche hypothesis (release from competition)- adaptive radiations
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Why do some groups have many more species than others? 2) Empty niche hypothesis (release from competition)- adaptive radiations
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Why do some groups have many more species than others? 3) ‘Species selection’: species with particular characteristics are more likely to speciate or less likely to go extinct -distinct from microevolution: all species might be equally adapted, but those with high ‘species fitness’ will become more abundant over evolutionary time
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Species Selection against selfers? -Work in Amsinkia shows that selfing evolved many times, but does not persist over long evolutionary timescales
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-Burst of diversification in Aquelegia genus tied to evolution of nectar spurs
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lecture_18_macroevolution_2_SW - Why do some groups have...

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