Module 8
1. Module 8
1.46. Page 4
Module 8—Populations, Individuals, and Gene Pools
Reflect and Connect
When wildlife managers see population numbers deviate from an expected growth curve, it indicates a problem. Apply your knowledge of growth curves to different species and their problems by completing the following questions.
Self-Check
SC 10. In Lesson 10, you graphed the data from a population of caribou from 1910 to 1950. The graph showed an extended period of exponential growth followed by a crash. Considering what you know now about the characteristics of K-selected species, was the graph typical? Why or why not?
SC 11. According to the table you created in SC 1 earlier in this lesson, are humans r- or K-selected? View “Figure 20.22” on page 733 of your textbook. Does the population growth curve support your decision? Why or why not?
SC 12. Review pages 733 and 735 in your textbook and view the age pyramids in “Figure 20.23” on page 735 to see age-pyramid representations of growth rates in the Congo, Sweden, and Germany. Which of the countries shows exponential growth? Negative growth? Stationary growth?
Self-Check Answers
SC 10. No, caribou are K-selected (large, long lifespan, nurture their young) and should show an S population growth curve. There should be a short period of exponential growth that flattens out due to environmental resistance, followed by a relatively stable carrying capacity population.
SC 11. Humans are K-selected by definition, but the human growth curve shows extended exponential growth typical of r-selected species. The best explanation is that technology has raised the carrying capacity of the environment to extend the period of exponential growth. There is evidence that, in recent years, the slope of the curve is starting to flatten somewhat.
SC 12. Congo shows exponential growth.
Germany shows negative growth.
Sweden shows stationary growth.
Module 8: Lesson 11 Assignment
Before you begin the Lesson 11 Assignment, you may wish to do the review questions on pages 716 and 737. Your teacher can help you select the questions best suited to your needs.
Retrieve the Module 8: Lesson 11 Assignment that you downloaded at the beginning of the lesson. Complete the assignment, save a copy to your course folder, and submit a copy to your teacher for assessment.