Discussion and Review Questions of Sexual Selection and Speciation | BIOL 5532, Study notes of Theory of Evolution

Download Discussion and Review Questions of Sexual Selection and Speciation | BIOL 5532 and more Study notes Theory of Evolution in PDF only on Docsity! Evolution BIOL5532 Discussion and review questions Sexual selection and speciation 1. Define sexual selection. Why is an increase in fecundity not likely to be an example of a sexually selected trait while female preferences for particular males would be an example of a sexually selected trait? ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 2. What two forms of competition drive evolution by sexual selection? ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 3. What traits are favored under scramble competition? Give an example of an organism that exhibits strong scramble competition for mates. ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 4. What traits are favored under sperm competition? Give an example of an organism that exhibits sperm competition. ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 5. Mathematically define the change in the male trait and change in female preferences under a Fisherian model of sexual selection. Be sure to define all the terms in your equation. ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 6. Explain exactly why female preferences evolve under a Fisherian model of sexual selection when there is no direct selection on female preferences. ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 7. For a particular population the slope of equilibrium between mean female preference and mean male ornament is 0.9. If the covariance between the female preference and the male trait is 0.020 and the genetic variance for the male trait is 0.021 will the traits be stable or will they runaway from equilibrium? ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 8. What is a testable prediction of the Fisherian model of runaway sexual selection? Is there support for this prediction in nature? Where? ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 9. Contrast indicator models of sexual selection with Fisherian models. ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 10. Describe the good genes model of sexual selection. What benefits are there to females for biasing their mating towards particular males? ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 11. What requirements are there for both male ornaments and fitness such that good genes based sexual selection may operate?