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The Origin of Species. Species. Biological Species. Ring Species. Prezygotic Habitat Isolation Behavior Isolation Temporal Isolation Mechanical Isolation Gametic Isolation. Postzygotic Hybrid Sterility Hybrid Inviability Hybrid Breakdown. Barriers. Habitat Isolation.
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Species • Biological Species
Prezygotic Habitat Isolation Behavior Isolation Temporal Isolation Mechanical Isolation Gametic Isolation Postzygotic Hybrid Sterility Hybrid Inviability Hybrid Breakdown Barriers
Sympatric Speciation • Autopolyploidy
Sympatric Speciation • Allopolyploidy
Gradualism • Also called “Neodarwinism” • Small changes over time • Supporter: Ernst Mayr
Punctuated Equilibrium • Supporters: Niles Eldredge & Stephen J. Gould • Speciation occurs in episodic events – large periods of time with little change and short periods of time with large changes
Origin of Evolutionary Novelty Most novelties are modified versions of older structures • preadaptation
“Evo-devo” Evolutionary Biology and Developmental Biology working together
Homeotic Genes Hox Genes- position information
Evolutionary Trends • Evolutionary trends are not goal oriented
Adaptive Radiation The emergence of numerous species from a common ancestor introduced into an environment, presenting a diversity of new opportunities and problems