1. Chapter 35
Population Dynamics

2. Lesson Plans Day 1: Do Now Intro, Lecture 35. 1-35
Lesson Plans Day 1: Do Now Intro, Lecture Day 2: Do now: Human population connection Lecture 35.5, Lab: Bean mark and recapture, Interpreting Ecological data Quiz on Test 34-35

3. Read the introduction on page 699 How were starlings introduced to North America? Why? Why is this a problem? How are starling populations and human populations similar?

4. The Spread of Shakespeare's Starlings
The European Starling has become an abundant and destructive pest in North America
Introduced in 1890 because of mention in Shakespeare
Like the human population, is expanding and uncontrolled
Population ecology is concerned with changes in population size and the factors that regulate populations over time

6. 35.1 Populations are defined in several ways
A population is a group of individuals of a single species that occupy the same general area
Boundaries defined in relation to question being studied

7. POPULATION STRUCTURE AND DYNAMICS
35.2 Density and dispersion patterns are important population variables
Population density is the number of individuals of a species per unit area or volume
Environmental and social factors influence the spacing of individuals in various dispersion patterns
Clumped
Uniform
Random

10. 35.3 Idealized models help us understand population growth
Exponential growth model gives an idealized picture of unregulated population growth
Under ideal conditions, whole population multiplies by a constant factor

11. G = rN describes the J-shaped curve of exponential growth
G = population growth rate
r = intrinsic rate of increase
Population members' maximum capacity to reproduce
N = population size

12. Time Number of Cells 70 0 minutes 1 = 20 60 20 2 = 21 50 40 4 = 22 60
LE 36-04a
Time
Number of Cells 70
0 minutes 1
= 20 60 20 2
= 21 50 40 4
= 22
Number of bacterial cells (N) 60 8
= 23 40 80 16
= 24 30
100 32
= 25
120 (= 2 hours) 64
= 26 20
G = rN
3 hours
512
= 29 10
4 hours
4,096
= 212
8 hours
16,777,216
= 224 20 40 60 80
100
120
140
12 hours
68,719,476,736
= 236
Time (min)

13. G = rN(K - N)/K describes the S-shaped curve of logistic growth
Logistic growth model represents the slowing of population growth as a result of limiting factors
Limiting factors: environmental factors that restrict population growth
G = rN(K - N)/K describes the S-shaped curve of logistic growth
K = carrying capacity
(K - N)/K accounts for the leveling off of the curve

14. Breeding male fur seals
LE 36-04b 10 8
Breeding male fur seals
(thousands) 6 4 2
1915
1925
1935
1945
Year

15. LE 36-04c
G = rN
(K - N) K
G = rN K
Number of individuals (N)
Time

16. Predictions of logistic growth model for natural populations
Growth rate low when population is either small or large
Growth rate highest when population is at intermediate level
Does not fit any natural population perfectly
Useful starting point for studying population growth

17. Do Now: Read: Human population Connection Write 10 Facts from this article that you did not already know.

18. 35.4 Multiple factors may limit population growth
Population growth is density dependent
Birth rates decline and death rates rise in response to increasing population density
Organisms compete for limited resources
Density affects health of organisms
Abiotic factors may limit population growth before limiting factors become important

19. LE 36-05a
4.0
3.8
3.6
Clutch size
3.4
3.2
3.0
2.8 10 20 30 40 50 60 70 80
Density of females

20. Exponential growth Sudden decline
LE 36-05b
Exponential
growth
Sudden
decline
Number of aphids
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

21. Most populations are regulated by a mixture of factors and show fluctuation over time

22. LE 36-05c 80 60
Number of females 40 20
1975
1980
1985
1990
1995
2000
Time (years)

23. 35.5 Some populations have "boom-and-bust" cycles
Some populations fluctuate in density with regularity
May have complex causes
Example: snowshoe hare and lynx cycles

24. LE 36-06
Snowshoe hare
160
120 9
Lynx
Lynx population size
(thousands)
Hare population size
(thousands) 80 6 40 3
1850
1875
1900
1925
Year

25. THE HUMAN POPULATION CONNECTION
35.8 Human population growth has started to slow after centuries of exponential increase
The human population now stands at over 6.4 billion
Even with slowing growth, predicted to reach 7.3 to 8 billion by 2025

26. LE 36-09a 6 5 4
Human population size (billions) 3 2
The Plague 1
8000
B.C.
4000
B.C.
3000
B.C.
2000
B.C.
1000
B.C.
1000
A.D.
2000
A.D.

27. What is Earth's human carrying capacity? Ecological footprint
Amount of land needed to support human demands on Earth's resources
Exceeds ecological capacity in many countries
World is already in ecological deficit
Problem is not just overpopulation, but overconsumption
Possible limiting factors: food, space

28. Ecological footprint (ha per person)
LE 36-09b 16 14 12
New Zealand 10
USA
Germany
Ecological footprint (ha per person) 8
Australia
Netherlands
Japan
Canada
Norway 6
Sweden UK 4
Spain
World 2
China
India 2 4 6 8 10 12 14 16
Available ecological capacity (ha per person)

29. LE 36-09c Traffic in downtown Cairo, Egypt Manhattan, New York City
Refugee camp in Zaire

30. 35.9 Birth and death rates and age structure affect population growth
Demographic transition
Shift from high birth rates and death rates to low birth rates and death rates
Has occurred in most developed countries
Population size continues to grow until birth rate equals death rate
Reduced family size key
Related to status of women

31. Birth or death rate per 1,00 0 population
LE 36-10a 50 40 30
Birth or death rate per 1,00 0 population 20
Birth rate
Death rate 10
1900
1925
1950
1975
2000
2025
2050
Year

32. Age structure of a population
Proportion of individuals in different age groups
Affects population's future growth
Indicates social conditions
Varies in developing and developed countries
Demographic differences
Infant mortality
Life expectancy at birth

33. LE 36-10b Rapid growth Slow growth Decrease Afghanistan United States
Italy
Age
Male
Female
Male
Female
Male
Female
85+
80
7579
707
6569
606
5559
505
4549
404
3539
Primary
reproductive
ages
303
2529
202
1519
101
59
0 8 6 4 2 2 4 6 8 6 4 2 2 4 6 6 4 2 2 4 6
Percent of population
Percent of population
Percent of population

34. 35.10 Principles of population ecology have practical applications
CONNECTION
35.10 Principles of population ecology have practical applications
Principles of population ecology are useful in sustainable resource management
Maximum sustained yield
Improvement of habitat or provision of additional habitat to increase K
Reduction of population size
Challenged by economic and political pressures