The Origin of Species

Chapter 22, 23, 24

1. Explain the difference between natural selection and evolution.

2. What did Darwin mean by the phrase “descent with modification”?

3. Why do we think of populations, rather than individuals, as evolving?

4. How are homolgous and vestigial structures evidence of evolution?

5. Use the molecular homology seen in the hemoglobin protein as evidence of evolution.

6. What about the fossil record supports the theory of evolution?

7. How can the Hardy-Weinberg theorem be used to measure evolutionary change?

8. How do the bottleneck effect and founder effect contribute to changing allelic frequencies?

9. We know that geographic isolation and habitat differences can result in changes in populations. Use the mice in Madeira and yarrow plants in the Sierra Nevada mountains as evidence.

10. What are the three types of selection we can observe in populations?

11. How do diploidy and heterozygote advantage help preserve variation?

12. Why is sexual reproduction the rule in nearly all eukaryotes?

13. How can sexual selection contribute to increased sexual dimorphism?

14. Why is evolution unable to produce “perfect” organisms?

15. Define the term species, and give some limitations of the biological species concept.

16. Barriers to reproduction fall into the categories of prezygotic and postzygotic barriers. Describe each of the following:

            a) Prezygotic barriers: habitat isolation, behavioral isolation, temporal isolation, mechanical isolation, gametic isolation

            b) Postzygotic barriers: reduced hybrid viablity, reduced hybrid fertility, hybrid breakdown

17. Identify and give an example of each of the two major types of speciation.

18. Many plant species have arisen through sympatric speciation by means of polyploidy. Explain.

19. Define and explain adaptive radiation. What evidence is there for it?

20. Explain the difference between punctuated equilibrium and gradualism? How can the fossil record make gradualism appear like punctuated equilibrium?

21.How is it that complex structures like the eye could have arisen?

22. How can heterochrony provide an explanation for the diversity we see among organisms?

23. How can homeotic genes be used to explain macroevolution?