1. 11/11 and 11/12 11/12 ATB  Review: What is a population? Today:
Go over the tests --- questions?
Start new chapter on populations and population growth

2. Chapter 5 - Populations

3. 5.1 How Populations Grow

4. How We Describe Populations
Four ways to describe a population:
Geographic Range
Density and Distribution
Growth Rate
Age Structure

5. Describing Populations
How do you describe an organisms geographic range?
Where it lives (area inhabited by the organism)
Density and Distribution
Population density –
number of individuals per unit area
Distribution –
How organisms are spaced out

6. Population Distribution

7. Population Distribution

8. Population Age Structure
Shows the number of individuals of each age
Why is this important for describing populations?
Allows us to predict what the population will do in the future.

9. 11/13 and 11/14
11/14 ATB  What will the population probably do in the future? (increase, decrease, remain stable)
Today:
Continue describing populations
Start carrying capacity assignment

10. Scientists use age structure pyramids to predict future growth.
What will populations do in the future?

11. Population Growth What can cause a population to increase or decrease?
Birthrates
Death Rates
Immigration
Emigration

13. Types of Growth What are the two typical types of growth curves?
Exponential
Logistic

14. Exponential Growth Exponential Growth – Draw the curve for exp. growth
Growth seen typically under ideal conditions with unlimited resources
Seen by a “J” shaped curve
Does it occur in nature?
For short periods of time, but inevitably it must slow down.
Why?
Resources become limited
Draw the curve for exp. growth

15. Exp. Growth in rapid vs. slow Reproduction

16. What type of curve does the human population show?

17. Logistic Growth Logistic Growth
Population growth that slows and then stops due to limiting factors
“S” shaped curve

18. Logistic Growth and Carrying Capacity
the number of individuals of a species an ecosystem can support
The flat place on the graph where the population levels off is called the carrying capacity of the population.

19. 5.2 Limits to Growth

20. Book Assignment
Page 135
#1-4

21. What controls the carrying capacity?
The carrying capacity is controlled by the ecosystems limiting factors.
Limiting Factors –
factors that keep organism population numbers from growing out of control

22. Limiting Factors
List five factors that could limiting the population of deer in the Pennsylvania.
Competition
Predation
Parasitism / Disease
Weather events
Natural Disaster

23. List four factors that keep a turkey population from getting too high.
Weather Conditions
Extreme Weather
Natural Disasters
Habitat Quality
Competition
Species Survival
Predation
Parasitism and Disease
Reproduction

24. 11/5 and 11/18 11/18 ATB  What controls the carrying capacity? Today:
Quick review
Carrying capacity assignment

25. Review Questions What are the two types of growth curves we discussed?
Describe the two growth curves.
What is population density?
What is population distribution?
What 4 factors affect a populations size?
What is carrying capacity?
What are limiting factors?

27. 11/19 and 11/20 11/20 ATB  List any three limiting factors. Today:
Carrying capacity assignment  due Thursday
Describe density dependent / independent factors

28. Carrying Capacity Questions
#2 and #3 on the assignment…
Any other questions?
Assignment due Thursday

29. Review Quiz What could occur to this population in the future?
A. Rapid growth
B. Slow growth
C. Decreasing growth
D. Steady growth
What type of growth is very rapid?
A. logistic
B. exponential
C. limiting factors
The number of organisms the ecosystem can support.
A. limiting factor
B. carrying capacity
C. exponential growth
D. habitat
T / F: Emigration is when individuals leave a population.

30. Assignment
Page 135
#1-4
This will NOT be collected today. We will add another assignment to the page and THEN it will be collected.

31. 11/21 and 11/22
11/21 ATB  What controls the carrying capacity of a habitat?
Today:
Turn in your carrying capacity graphs
Describe density dependent / independent factors

32. Density-Dependent Limiting Factors
Limiting factors that begin affecting a population which has reached a certain size
Population gets large = density-dependent limiting factors start affecting the population
What is going to happen to intraspecific competition as the population grows. Give an example
It will increase
More individuals begin competing for increasingly scarce resources like food and shelter.

33. Density-Dependent Limiting Factors
Predation and Herbivory
Describe how predation and herbivory act as a density-dependent limiting factor
As the population of predators go up the population of prey will decrease. This causes the predators to then decrease.
Same thing happens with herbivores and if too large a population is present the plant population will be affected

34. Density-Dependent Limiting Factors
Parasitism and Disease
In large populations parasites and disease are able to spread more rapidly
Stress From Overcrowding.
Too much competition / fighting can cause stress individuals, which can lead to weakened ability to fight diseases

35. c A B Review: Where is the carrying capacity reached?
Where is the growth the fastest?
Where is the growth slowing down?
What controls the carrying capacity? A B c

38. Density-Independent Limiting Factors
Factors that affect the population regardless of the population size
Can cause a population crash
Examples:
Unusual weather
Drought / floods
Fires

39. Density Dependent vs. Density Independent
Label the the following as “density dependent” or “density independent”
A fire kills off a number of the population.
Predators start congregating around the prey population.
A disease runs rampant through the population.
A cold winter causes starvation of a number of the species
Organism become weakened b/c of stress from overcrowding and competition

40. 5.2 Assessment
Page 141
#1-3

41. Quick Talk Carnivore Carrying capacity Carrying capacity
Limiting factors
Exponential growth
Producer
Carrying capacity
Exponential growth
Decomposer
Limiting factors
Omnivore

42. 5.3 Human Population Growth

43. Human population growth
Review:
What type of growth curve does the human population have?
Exponential
Thomas Malthus predicted in the early 1800’s that the human population would crash b/c of famine and disease
Famine and disease are examples of density _____dependant______ factors.
Why didn’t Malthus’ predictions come true?
technology

44. Human Growth

47. What is our approx. pop? Human Population Clock
What problems are we causing with our high population numbers?
Pollution
Damage to ecosystems
Causing extinctions of species

48. HE WHO ONCE DOMINATED THE EARTH –
IN MEMORY OF
MAN
2,000,000 BC – AD 2030
HE WHO ONCE DOMINATED THE EARTH –
DESTROYED IT
WITH HIS WASTES
HIS POISONS AND
HIS OWN NUMBERS

49. Most populated Countries
1.35 billion = China
1.23 billion = India
313 billion = US

50. Where is human pop. growth the highest? Why??

51. Demographic Transition
Shows the predicted change in birth rates / death rates as a country industrializes
PREDICT the birth rate and death rates for the following countries (low or high)
Affluent country with health care:
BR = ____ DR = ____
Very poor country: BR = _____ DR = _____
Poor nation with some access to medicines:
BR=____ DR=______

52. Demographic Transition
Stage 1 = high birth rates and high death rates
Stage 2 = high birth rates but death rates fall
Stage 3 = low birth rates and low death rates

53. Why are birthrates high during Stage 1 and 2?
Lack of birth control
Many babies do not survive
Why do death rates decrease as a population industrializes?
Better medicine
Better sanitation
Why do birth rates fall during stage 3 of demographic transition?
Access to birth control
Women want education or career

54. Demographic Transition

57. Age structure and Population Growth
Age Structure Diagrams
Help predict future population growth trends

61. The End

62. 5.3 Assessment
Pg 145
#1-2

68. POPULATION SIZE * 1,000 Y E A R (1900)75 70 65 60 55 50 45 40
POPULATION SIZE * 1,000 35 30
carrying capacity 25 20 15 10 5
Y E A R (1900)

71. Climate Change – General Info
The majority of greenhouse gasses have been emitted since the beginning of – the industrial revolution
The burning of fossil fuels (and biomass) releases carbon that has been trapped for millions of years
This carbon is released in the form of
CO2
The three main fossil fuels are
coal, oil and natural gas
Slash and burn farming reduces the ability of Earth’s forests to soak up the CO This also releases the carbon that was trapped in the trees, into the atmosphere in the form of carbon dioxide

72. Population size and CO2 Industrializing nations a problem?
What is the main issue with industrializing nations that have very large populations?
They are burning fossil fuels at an enormous rate
(more people = more pollution)
Industrializing nations with large populations?
China pop = 1.3 billion
India pop = 1.1 billion
US pop = 300 million

73. Evidence of Global Warming…?

74. CO2 and Temp
What we see is a positive correlation between the temp. and the levels of CO2 in the atmosphere.
This means the more carbon dioxide there is, the higher the temp. will be
CO2 levels are now at the highest level in 150,000 years (actually 650,000 years)

75. Reading the graphs…

76. Average Temp Increase - (Since 1855)
Current Temperature Increase:
Overall temp. on earth (near the surface) has increased 1.33 degree Fahrenheit (± 0.32 F) in the 20th century.
Models predict that the temp. will rise a further 2.0 to 11.5 °F in the st century.
Hottest Years in 150
The hottest years recorded, EVER since recording began in 1880 were within the last 10 years