1. Roadmap for Today’s class
Population Growth
“r-selected” and “K-selected” species

2. Population Growth Worksheet

3. 1)Ai)

4. Ability of rabbits to make babies X the number of rabbits you have
1)Aii)
The number of rabbits next year = The number you have now + number of new baby rabbits
Ability of rabbits to make babies X the number of rabbits you have

5. Time (months) Population size (N) 1 2 3 4 5 6 7 8 9 10 11 12 50 100
1) A) v)
rNt
(Years)
Time (months)
Population size (N) 1 2 3 4 5 6 7 8 9 10 11 12 50
100
150
200
250
300
350
400
450
500
(Years)
x 0.3 = =
x 0.3 = =

6. 1)B) C)

7. 1) C) ii)
(Population Growth rate) * (the size of the population)
Proportion of Carrying capacity that is occupied
Proportion of Carrying capacity that is still open
Population size
Effect of K on Growth Rate as N approaches K. K= 1,000, r = 0.1
(Adapted from Campbell, et al, Biology Concepts and Connections 6th ed.) N rN K
1-N
dN/dt = rN(1-N/ K) 10 1
0.01
0.99
100
0.1
0.9
9.00
400 40
0.4
0.6
24.00
500 50
0.5
25.00
600 60
700 70
0.7
0.3
21.00
900 95
0.05
0.25
1,000
1.0
0.00
Logistic growth equation: Rate of change = rate at which baby rabbits are added to the population.
As population reaches carrying capacity, rate approaches zero - no new rabbits.

8. Breeding male fur seals
1) C) ii)
Year
Breeding male fur seals
(thousands)
1915
1925
1935
1945 2 4 6 8 10

9. 1) D)

10. Lynx population size (thousands) Hare population size
Snowshoe hare
Lynx population size
(thousands)
Hare population size
Year
1850
1875
1900
1925 40 80
120
160 3 6 9

11. 1) E i)

12. 1) E ii)

13. 1) E iii)

14. 1) E iv)

15. 2) A-C)

16. 2) Di) Experimental transplant of guppies Predator: Killifish; preys
Males
Females
Experimental
transplant of
guppies
Predator: Killifish; preys
mainly on small guppies
Guppies:
Larger at
sexual maturity
than those in
pike-cichlid pools
Pools with killifish,
but no guppies prior
to transplant
Predator: Pike-cichlid preys mainly on large guppies
Guppies: Smaller at sexual maturity than
those in killifish pools
11 years
later
Mass of guppies
at maturity (mg) 40 80
120
160
200
67.5
76.1
161.5
185.6
Age of guppies
at maturity (days) 20 60
100
48.5
58.2
85.7
92.3
Control:
Guppies from pools
with pike-cichlids
as predators
Experimental:
Guppies transplanted
to pools with killifish

17. 2) Dii)
Semi-Dwarf Wheat varieties

18. 2) Diii)