Patterns And Mechanisms Worksheet

Name: _________________________________ Date: _________________ Per. ___

Vocabulary Review: Distinguish between the terms in each of the following pairs 1. immigration, emigration ____________________________________________________ __________________________________________________________________________ 2. stabilizing selection, directional selection ______________________________________ __________________________________________________________________________ 3. gene flow, genetic drift ______________________________________________________ ___________________________________________________________________________ Multiple Choice: Write the correct letter on the blank line provided. ______ 1. The corresponding changes of two or more species that are closely associated with each other, such as a plant and an animal that pollinates it, are called a. adaptive radiation. b. divergent evolution. c. convergent evolution d. coevolution ______2. Artificial selection is used to a. speed up the process of divergent evolution. b. slow down the process of convergent evolution. c. produce vestigial structures in selected species of animals. d. study the evolutionary history of organisms that contain similar proteins. ______3. Genetic drift is most likely to occur in a. small populations. b. large populations. c. populations that migrate d. populations that have a low frequency of mutation ______4. Starlings produce an average of five eggs in each clutch. If there are more than five, the parents cannot adequately feed the young. If there are fewer than five, predators may destroy the entire clutch. This is an example of a. disruptive selection. b. stabilizing selection. c. directional selection. d. sexual selection. ______5. For a population to be in genetic equilibrium,

a. individuals must not enter or leave the population. b. the population must be evolving. c. the population must be small. d. selection must occur. Short Answer: Answer the following questions in complete sentences. 6. What is one potential negative consequence of nonrandom mating based on geographic proximity?

7. How might being brightly colored increase the fitness of the males of some bird species?

8. What types of individuals in a population are represented by the two ends of a bell curve?

9. How are the terms gene pool and allele frequency related?

10. How is artificial selection used in agriculture?

11. What is the founder effect? Give an example of this type of evolution.

12. Not all characteristics which contribute to longer life become more common in the population. Some characteristics contribute to long life, but not more offspring. For example, a female cat which is sterile and cannot have any offspring may live longer because she will not experience the biological stresses of repeated pregnancies. Explain why a characteristic like this which contributes to a long life, but with few or no offspring, would not become more common as a result of evolution by natural selection.

13. Critical Thinking: Does a gene pool include the genes of individuals that cannot reproduce? Explain your answer.

14. Critical Thinking: If a cow develops a preference for eating white four o’clock flowers and ignoring pink and red four o’clock flowers, what type of selection is being demonstrated? Would the cow eventually eliminate all white four o’clock flowers from the population on which it feeds?

Matching: Use the terms coevolution, convergent evolution, divergent evolution and adaptive radiation. 15. __________________________ Process of change in 2 or more species that are dependent on each other. 16. __________________________This type of evolution can result in the formation of a new species 17. __________________________Natural selection has produced similar adaptations in organisms in response to similar environments 18. __________________________Serval cats and Maned wolf both live in tall grassy areas, eating rodents and lizards. These two animals both have long ears which allow them to hear prey as well as long legs which help them chase their prey. 19.___________________________Acacias are small, Central American trees in the Leguminosae. They have large, hollow thorns. The acacia ants live in the thorns. On the tips of its leaflets, the plant makes a substance used by the ants as food. The ants defend the tree from herbivores by attacking/stinging any animal that even accidentally brushes up against the plant. The ants also prune off seedlings of any other plants that sprout under “their” tree 20. ___________________________The Galapagos Finches are an example of this type of evolution Interpreting Data: The table below gives descriptions of four female mice that live in a beach area which is mostly tan sand with scattered plants. Color of fur Age at death # pups produced by each female Running speed

Black 2 months 0 8 m/min.

Tan 8 months 11 6 m/min.

Tan & Black 4 months 3 7 m/min.

Cream 2 months 0 5 m/min.

21. According to the definition given for fitness, which mouse would biologists consider the fittest? Explain.

Below are descriptions of four male lions. Name George Age at death 13 years # cubs fathered 19 # cubs surviving to adulthood 15 Size 10 feet

Dwayne 16 years 25 14 8.5 feet

Spot 12 years 20 14 9 feet

22. Which lion would biologists consider the “fittest”? Explain.

Tyrone 10 years 20 19 9 feet

23. A population of birds eats seeds. Small seeds can be eaten by birds with small beaks. Larger, thicker seeds can only be eaten by birds with larger, thicker beaks. Suppose there is a shortage of small seeds but that there are still many large seeds. a. Draw a new curve on the graph to show how the distribution of beak sizes might change as a result of selection in this new environment.

Use the graph above to answer the following questions: b. Which birds in this population have the highest fitness?

c. Explain how natural selection could lead to the change you predicted.

Graphing: 24. For your study, you will be examining a specific population of spiny cacti, which is originally in genetic equilibrium. A road is built quite close to the study site, which keeps away the treacherous and parasitic insects, but with the road comes the tourists. In many desert areas of the United States, passing cactus lovers like to pick up a souvenir cactus to take home with them after a day-trip out into the desert. This is a serious problem in some areas because the tourists always take the better looking cacti, and these happen to be the ones with the middle-spine-numbers. Years of collecting have left their toll on the roadside cacti. Using this background knowledge and the data collected below; create a line graph of both the original population of cacti and the current population. Remember to label your x and y axis and give your graph a title.

Original Population Number of Cactus 4 12 25 13 8 4 2

Number of Spines 71 82 95 106 113 122 130

Current Population (Yrs later) Number of cactus 10 22 5 12 14 9 4

Number of Spines 72 80 93 108 110 120 129