9/13/20171Today’s Objectives• Finish Darwin’s 5 Theories• Watch Voyage to the Galapagos– Elevator (Digital Content Library) on Moodle• Sexual Selecton229/13/20172Darwin’s 5 theories regarding evolution1. Species change [evolution as such]2. All organisms share a common ancestry3. Evolution is gradual4. Evolution leads to speciation5. Evolution occurs through Natural SelectionThis is not ONE THEORY of evolution but SEVERAL THEORIES3The Three Necessary and Sufficient Conditions for Natural Selection1. Variation in a trait2. Inheritance of the trait3. Differential reproductive success based on that trait 49/13/20173Modes of Selection5Population before selectionPopulation after selectionTitle: Effects of NS on mouse fur color- - - - - before selectionafter selectionEvolution ≠ Natural Selection• Natural selection is one (!) mechanism that leads to evolution• Adaptation = the result of long-term selection in one direction– Adaptations occur in populations69/13/20174Perfect Adaptation7Adaptations always have a cost andso there is an inherent trade-off.7Scientific American: Voyage to the Galapagos(video ID
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