Biology I U4P2: Study Guide
Name:
Per.
1. Label the graphs to the right with the appropriate pattern of
selection.
a.
b.
c.
2. What is the largest and most influence force driving evolution?
3. What are the three things that may cause variation in genotype?
4. Does natural selection act on genotypes or phenotypes? Explain.
5. List the five causes of evolution.
6. Will evolution occur if a population is in equilibrium? Explain.
7. A male lion has a long dark mane that attracts females. Which type of selection does this example
exhibit?
8. Compare and contrast the founder’s effect to the bottleneck effect.
9. On the Galapagos Islands, finches adapted over time to different food sources through changes in their
beak structure. What would you expect to happen to the species diversity of this population?
10. In an owl population, a mutation occurs that results in a new feather color allele. What would need to
occur in order for the new feather color allele to become more common in the owl population?
1
11. Write the type of adaptation for each scenario provided. (Structural adaptation, Behavioral adaptation,
or Physiological adaptation)
a. A male peacock has many beautiful tail feathers to display females.
b. The coral snake is highly venomous snake, if bitten a human could die within a couple of hours
without treatment.
c. A male peacock displays his beautiful tail feathers in attempt to attract a female.
d. Chickens have four toes on each foot to help balance on tree branches when they roost at night.
12. How does population size affect the population’s vulnerability to loss of genetic diversity as a result of
genetic drift?
13. The brown recluse spider is very venomous; when humans are bitten they need immediate medical
attention to slow the venom’s toxicity. There are several house spiders that look almost identical to the
brown recluse and in doing so benefit from the awareness of possible predators. Which type of selection
does this example exhibit?
14. What is the difference between gradualism and punctuated equilibrium?
15. Write the definition and provide examples of each term:
a. divergent evolution
b. coevolution
c. convergent evolution
d. gene pool
e. gene flow
f. punctuated equilibrium
g. gradualism
h. structural adaptation
i. behavioral adaptation
j. physiological adaptation
2
16. Define each type of isolation and provide an example used in class.
a. behavioral isolation
b. temporal isolation
c. ecological isolation
d. geographic isolation
e. mechanical isolation
17. Which type of speciation can occur if two groups mate at different times of the year?
18. What type of speciation occurs when new species arise as a result physical barrier such as a Colorado
River?
19. What is the major difference between sympatric and allopatric speciation?
20. Compare and contrast prezygotic isolation and postzygotic isolation. Do both lead to speciation?
Explain.
21. Discuss how gene flow and interbreeding are affected by geographic isolation and how that leads to
speciation.
22. What is the sixth mass extinction?
23. List the causes of the sixth mass extinction.
24. What is extinction? Why does it occur
3
25. Commercial fishers in the northwest Pacific were paid by number of fish, rather than by the weight of
total combined fish, for pink salmon. The fishers increased the use of a type of net that selectively
catches many smaller fish. What effects on the salmon population would we expect to occur due to this
change in fishing techniques over the next 20 years? Which pattern of selection would most likely
occur?
26. Compare the three definitions of the term species. Which definition do we use today? Explain why.
27. A crop field was plagued with an insect infestation and the crops died. The following year farmers
decided to take a unique approach to combat the insects; to protect the new field against these insects
farmers crossed the old crop with a GMO crop that contain a gene to produce a toxin that “naturally”
repels the insect. Explain how natural selection would promote the new toxin producing crop population
once the two crops were crossed? Include in your answer the terms: toxin producing gene, survive and
reproduce, select against.
28. When hybrids between closely related species occur, they are often inviable or, if they live, they are
sterile. Should the resulting hybrid be considered a new species? Provide your reasoning.
4