1. Population Dynamics

2. Definition of Population
All individuals that belong to the same species and live in a given area at a particular time.

3. 4 Population Size Four variables that govern population size: Births
Deaths
Immigration
Emigration
Population change = [ births + immigration ]
- [ deaths + emigration ]

4. Population Size
Population size is determined by the interplay between it biotic potential and environmental resistance.
Biotic Potential - capacity of a population for growth
Environmental Resistance - all the factors acting jointly to limit the growth of a population

5. Carrying Capacity
Carrying Capacity (K) - the number of individuals of a given species that can be sustained indefinitely in a given space; determined by biotic potential and environmental resistance.

6. Limiting Factors
Density-dependent- A factor that influences an individuals probability of survival in a manner that depends on the size of the population. Ex: food, disease, reproductive behavior
Density-independent- A factor that has the same effect on an individual’s probability of survival and amount of reproduction at any population size. Ex: tornadoes, hurricanes, floods, fires, volcanic eruptions
Density-dependent factors tend to be biotic. Density-independent factors tend to be abiotic.

7. Logistic and Exponential
Logistic Growth - involves exponential growth when a population is small and a steady decrease in growth in time as the population approaches the carrying capacity
S-shaped curve
Exponential Growth - a population that does not have resource limitations
J-shaped curve

8. Which of the following is not an example of a density-independent factor?
Drought
Competition
Forest Fire
Hurricane
Flood
Do You Know?

9. Do You Know? Competition
Which of the following is not an example of a density-independent factor?
Drought
Competition
Forest Fire
Hurricane
Flood
Do You Know?

10. Population Distribution
Clumping: Most Common. Safety in numbers, social interaction, mating and caring for young, resources are clumped.
Uniform: Not as common, Used because of scarcity of resources.
Random: Quite rare. No apparent pattern.

11. Predator-Prey Relationships

12. Use Figure 1 to answer the following questions.
Time is represented on the ___-axis.
The number of individuals is represented on the ___-axis.
At which point on the curve is the population increasing at the fastest rate? ___
At which point on the curve has the population reached its carrying capacity? ___

13. Use Figure 1 to answer the following questions.
Time is represented on the X-axis.
The number of individuals is represented on the Y-axis.
At which point on the curve is the population increasing at the fastest rate? II
At which point on the curve has the population reached its carrying capacity? III

14. Prey population rises due to decline in predator population.
Predation is an important means of keeping the prey population in check. Read the following lettered descriptions. Use the letters to label Figure 3 to show what is happening at each point on the curve.
Prey population rises due to decline in predator population.
Predator population rises due to rise in prey population.
Prey population falls due to increase in predation.
Predator population falls due to decrease in prey population.
Prey population rises.

15. Prey population rises due to decline in predator population.
Predation is an important means of keeping the prey population in check. Read the following lettered descriptions. Use the letters to label Figure 3 to show what is happening at each point on the curve. E B C D A
Prey population rises due to decline in predator population.
Predator population rises due to rise in prey population.
Prey population falls due to increase in predation.
Predator population falls due to decrease in prey population.
Prey population rises.

16. Do You Know? As the size of a white-tailed deer population increases,
the carrying capacity of the environment for white-tailed deer will be reduced.
a volcanic eruption will have a greater proportional effect than it would be on a smaller population.
the effect of limiting resources will decrease.
the number of gray wolves, a natural predator of the white-tailed
deer, will increase.
E. white-tailed deer are more
likely to become extinct.
Do You Know?

17. Do You Know? As the size of a white-tailed deer population increases,
the carrying capacity of the environment for white-tailed deer will be reduced.
a volcanic eruption will have a greater proportional effect than it would be on a smaller population.
the effect of limiting resources will decrease.
the number of gray wolves, a natural predator of the white-tailed
deer, will increase.
E. white-tailed deer are more
likely to become extinct.
Do You Know?

18. K-Strategist and r-Strategist
K-Strategist Species (competitor) - reproduce late, have few offspring with long generation times (K)
have big bodies, live for a long time, spend little of their energy on reproduction
Type I survivorship curves
tend to do well in competitive conditions when pop. is near carrying capacity
prone to extinction
r-Strategist Species (opportunist) - species with a high intrinsic rate of increase (r)
Many small and unprotected young
Most die before reaching reproductive age
Type III survivorship curves

19. Survivorship Curves

20. Which of the following characteristics are typical of r-selected species?
I They produce many offspring in a short
period of time.
II They have very low survivorship early in life.
III They take a long time to reach maturity.
I only
II only
III only
I and II
II and III
Do You Know?

21. Which of the following characteristics are typical of r-selected species?
I They produce many offspring in a short
period of time.
II They have very low survivorship early in life.
III They take a long time to reach maturity.
I only
II only
III only
I and II
II and III
Do You Know?

22. History of Human Population

23. Filling Up

24. the time it takes for a population to double
Doubling Time
the time it takes for a population to double
Rule of 70
= number of years to double
70/GROWTH RATE

25. How many years does it take for a country with a population growing at 2% to double its population?
Do You Know?

26. How many years does it take for a country with a population growing at 2% to double its population?
Do You Know?

27. Crude Birth Rate and Crude Death Rate
Crude Birth Rate (CBR) - number of live births per 1000 people in a population in a given year
Crude Death Rate (CDR) - number of deaths per 1000 people in a population in a given year

28. Fifteen Years Ago…. 2012 World Census Average crude birth rate – 19
Average crude death rate - 8
Rate of World's Population Change (%) = (Birth Rate - Death Rate)/1000 people x 100
= (CBR - CDR)/10
1.1% Population growth

29. Global Fertility Rate There are two types of fertility rates
1. Total Fertility Rate (TFR)
TFR is an estimate of the average number of children a woman will have during here childbearing years under current age-specific birth rates.
2. Replacement Level Fertility
This is the number of children a couple must bear to replace themselves.(2.1 in developed countries and 2.5 in developing countries). These numbers are greater than 2 because some female children die before reaching their reproductive years.

30. A metropolitan region of 100,000 has 2,000 births, 500 deaths, 200 emigrants, and 100 immigrants over a 1-year period. Its population growth rate is
1.2 percent
1.4 percent
1.6 percent
1.8 percent
2.0 percent
Do You Know?

31. A metropolitan region of 100,000 has 2,000 births, 500 deaths, 200 emigrants, and 100 immigrants over a 1-year period. Its population growth rate is
1.2 percent
1.4 percent
1.6 percent
1.8 percent
2.0 percent
Do You Know?

32. Age Structure Diagram
Age Structure Diagrams - show the proportion of the population at each age level.
Three main age categories:
pre-reproductive (ages 0-14)
reproductive (15-44)
post-reproductive (45+)

33. Age Structure Diagrams
Rapid Growth
Guatemala
Nigeria
Saudi Arabia
Slow Growth
United States
Australia
Canada
Male
Female
Zero Growth
Spain
Austria
Greece
Negative Growth
Germany
Bulgaria
Sweden
Ages 0-14
Ages 15-44
Ages

34. Demographic Transition
Demographic Transition: As countries become more industrialized, first their death rates and then their birth rates decline.
This Transition takes place in four stages:
pre-industrial stage - harsh living conditions, high infant mortality rates, high death rate; need a high birth rate .. pop. growth is small (or zero)
transitional stage - industrialization begins, rise in food production, improved health care, reduction in death rate, birth rate remains high .. pop. grows rapidly (2.5-3%/year)

35. Demographic Transition(cont.)
industrial stage - industrialization is widespread. Birth rate drops and approaches the death rate. Better access to birth control, reduced infant mortality, incr. job opportunities for women, high cost of raising children, HS and college educations. Pop. grows but at a slower rate.
postindustrial stage - Birth rate declines further, equals death rate ==> ZPG.

36. Demographic Transition
Low
High
Relative population size
(number per 1,000 per year)
Birth rate and death rate 80 70 60 50 40 30 20 10
Stage 1
Preindustrial
Stage 2
Transindustrial
Stage 3
Industrial
Stage 4
Postindustrial
growth rate
Increasing Growth
Very high
Decreasing
Zero
Negative
Birth rate
Total population
Death rate
Time

37. Zero Population Growth
ZPG
when births plus immigration equal deaths plus emigration

38. Which of the following countries best exemplifies phase 4 of a demographic transition?
Argentina
China
India
Japan
Mexico
Do You Know?

39. Which of the following countries best exemplifies phase 4 of a demographic transition?
Argentina
China
India
Japan
Mexico
Do You Know?