Download A look at populations (5 points) Part 1: In 1911, 25 reindeer, 4 males

A look at populations
(5 points)
Part 1:
In 1911, 25 reindeer, 4 males and 21 females, were introduced onto St. Paul Island near Alaska. On St. Paul
Island there were no predators of the reindeer, and no hunting of the reindeer was allowed. Study the graph
below and answer the questions.
Changes in the reindeer population on St. Paul
Island between 1911 and 1950
1. In 1911 the population was 25
reindeer. What was the size of the
population in 1920? What was the
difference in the number of reindeer
between 1911 and 1920? What was
the annual increase in the number of
reindeer between 1911 and 1920?
2000
2. What was the average annual
Increase in the number of reindeer
in the years between 1920 and 1930?
1000
3. What was the average annual
Increase in the number of reindeer in
The years between 1930 and 1940?
1500
500
0
1910
1920
1930
1940
1950
1960
4. What was the largest population of
Reindeer and in which year did it occur?
5. Explain why the population could survive with starting numbers of 21 females but only 4 males.
6. Explain why before 1930, even without predation the population size decreased for a short period.
7. St. Paul island is 200 miles from the mainland. What kind of population changes would this eliminate?
8. Due to St. Paul island’s location explain why reindeer on the mainland may grow genetically apart from
those on St. Paul Island and what this is called.
9. What might account for the tremendous increase in the population of reindeer between 1930 and 1938, as
compared with the rate of growth during the first years on the island?
10. What things would account for the tremendous drop of in population after 1938?
11. If some of the 8 reindeer that were still alive in 1950 were male and some female, what do you think would
happen?
12. What evidence is there that carrying capacity for the reindeer on the island was exceeded?
13. What does this study tell you about unchecked population growth?
14. What can you assume about the eight reindeer that still remained?
15. Describe what occurred on St. Paul Island using the following terms: Natality, Mortality, Abiotic factors,
Biotic factors, Carrying capacity, Intraspecific competition, Interspecific competition, density independent
factors, density dependent factors, Limiting resources, ecological niche, geographic isolation, and the Founder
effect.
Part 2:
On a piece of paper graph the human population growth from the table below.
Human population growth between A.D. 1 and 2000
Date A.D.
Human population
Date A.D.
(millions)
1
250
1930
1000
280
1940
1200
384
1950
1500
427
1960
1650
470
1970
1750
694
1980
1850
1100
1990
1900
1600
2000
1920
1800
2010
Human population
(millions)
2070
2300
2500
3000
3700
4450
5300
6080
?
1.
2.
3.
4.
5.
Using you graph determine how long it takes each time the population doubled from A.D. 1 to 2000.
How much time did it take for the human population to double the first time after A.D. 1?
Is the amount of time for the human population to double increasing or decreasing?
What do you think the population will be in 2010?
What similarities do you see between the graph of the reindeer population and your graph of the human
population?
6. What are four important factors required to sustain population?
7. Have human reached their carrying capacity? How do you know?
8. What will happen when human population reaches the carrying capacity?
9. Which factor will be the most significant in keeping human population from reaching carrying capacity?
10. Describe human existence and population growth using the following: Natality, Mortality, Abiotic
factors, Biotic factors, Carrying capacity, Intraspecific competition, Interspecific competition, density
independent factors, density dependent factors, Limiting resources, and ecological niche.
Part 3 Look at the graph and answer the following.
1. Which line represents the predator and which one is
The prey explain?
2. Explain why those fluctuations in population are
occurring?
#1
#2