Chapter 24 Origin of Species
Objectives
| What Is a Species? | |||
| 1. | Distinguish between anagenesis and cladogenesis. | ||
| 2. | Define Ernst Mayr’s biological species concept. | ||
| 3. | Distinguish between prezygotic and postzygotic isolating mechanisms. | ||
| 4. | Describe five prezygotic isolating mechanisms and give an example of each. | ||
| 5. | Explain a possible cause for reduced hybrid viability. | ||
| 6. | Explain how hybrid breakdown maintains separate species even if fertilization occurs. | ||
| 7. | Describe some limitations of the biological species concept. | ||
| 8. | Define and distinguish among the following: ecological species concept, paleontological species concept, phylogenetic species concept, and morphological species concept. | ||
| Modes of Speciation | |||
| 9. | Distinguish between allopatric and sympatric speciation. | ||
| 10. | Explain the allopatric speciation model and describe the mechanisms that may lead to divergence of isolated gene pools. | ||
| 11. | Describe examples of adaptive radiation in the Galápagos and Hawaiian archipelagoes. | ||
| 12. | Explain how reproductive barriers evolve. Describe an example of the evolution of a prezygotic barrier and the evolution of a postzygotic barrier. | ||
| 13. | Define sympatric speciation and explain how polyploidy can cause reproductive isolation. | ||
| 14. | Distinguish between an autopolyploid and an allopolyploid species and describe examples of each. | ||
| 15. | Describe how cichlid fishes may have speciated in sympatry in Lake Victoria. | ||
| Adaptive Radiation | |||
| 16. | Define adaptive radiation and describe the circumstances under which adaptive radiation may occur. | ||
| 17. | Describe the two gene loci implicated in speciation in Mimulus. | ||
| From Speciation to Macroevolution | |||
| 18. | Explain in general terms how a complex structure can evolve by natural selection. | ||
| 19. | Define exaptation and illustrate this concept with an example. | ||
| 20. | Explain how slight genetic divergences may lead to major morphological differences between species. | ||
| 21. | Explain how the evolution of changes in temporal and spatial developmental dynamics can result in evolutionary novelties. | ||
| 22. | Define evo-devo, heterochrony, allometric growth, and paedomorphosis. | ||
| 23. | Explain why extracting a single evolutionary progression from a fossil record can be misleading. | ||
| 24. | Define and illustrate the concept of species selection. | ||
| 25. | Explain why evolutionary change is not goal-directed. | ||
