Population Dynamics Packet Name

Objectives:You will graph the population growth of different populations and use it to predict future growth. You will identify factors that affect population growth.

Background:There is a close connection between the human population of the Earth and many of the problems we currently face as a global society. Issues such as resource depletion, energy consumption, global food supplies, drinking water reserves, soil erosion, water and air pollution, global climate patterns and many others are directly related to the growing number of people living on our planet.

Prior to 1950, the death rate was high, which kept the numbers of humans from increasing rapidly. In the 19th Century, the agricultural revolution increased food production. The industrial revolution improved methods of transporting food and other good. In the 20th Century, advances in medicine, sanitation and nutrition have decreased the death rates further. These factors combined to produce the rapid growth of the human population in the 20th century.

Colonizing populations may undergo a rapid exponential increase in numbers as there are plenty of resources to allow a high birth rate while the death rate is often low. This produces a J-shaped curve that rises steeply as more and more individuals contribute to the population increase. As with any population, humans are also limited by factors such as space, amount of food and disease. The carrying capacity is the number of individuals that a stable environment can support. Authorities disagree on the maximum number of people that the earth can support, though the numbers generally range for 8 to 10 billion. As the population approaches its limit, it will start to encounter environmental resistance that will decrease the population.

Some countries have a much higher growth rate than others. Growth rate is the number of people born minus the number of people that die. Most countries are trying to reduce their growth rate. Zero population growth means that as many people are being born as there are dying - to achieve zero population growth, each couple would need to have no more than two children (to replace the parents). Even if this number is achieved, the population will continue to grow because the parents will still live on for decades, as their children have children and their children have children, and so forth. The United States reached zero population growth in the 1980's, and yet the overall population of the US still increases.

Part A Define the following terms-

a) Exponential growth-

b) Logistic growth-

c) Carrying capacity-

d) Environmental Resistance-

Part BAs seen in the figure below, since about 1950 differing population trends between the developing and industrialized regions of the world have further complicated the situation.

1. What was the approximate population of the world in 2000?

2. What percent of Earth’s people lived in developed countries then?

3. What is the predicted population for the world in 2050?

4. What percent of the world’s people will live in developing countries in 2050?

5. What increase is that in the number of people living in developing countries since 2000?

6. What type of graph does the overall population express?

Part CUse the graph below to answer the questions that follow.

1. Which country looks like it is experiencing exponential growth?

2. Which country looks like it has reached its logistic growth?

3. Which countries seem to have had environmental resistance? ________________ and _______________

4. Some countries look as if they have reached carrying capacity. Describe the relationship between the birth rates and death rates for a population that has stabilized/reached carrying capacity.

Part DThe earth’s known human population size is reported in the table on the next page

Procedure- Graph the data (label x-axis, y-axis and

provide a title)- Use all spaces given for the graph

Table 1. Earth’s Human Population SizeYear A.D. Number of People (in billions)

1650 .501750 .701850 1.01925 2.01956 2.51966 3.31970 3.61974 3.91976 4.01980 4.41991 5.52000 6.02004 6.42008 6.7

- Draw a smooth line that best connects all data points- Answer the analysis questions.

AnalysisIt took 1,649 years for the world population to double, going from 0.25 billion people to 0.50 billion people. 1. How long did it take for the population to double a second time?

2. How long did it take for the population to double a third time? A fourth time?

3. Based on your graph, in what year will the population reach 8 billion?

4. Does this graph represent an exponential curve or logistical curve?

5. What factors contributed to the world's overall population growth in the last 150 years (identify 3 things)?

6. If the carrying capacity of the earth was 9 billion people, when would this number be reached (according to your graph)?

7. What will happen when the human population exceeds the earth's carrying capacity? Answer in terms of population numbers as well as resources.

8. Name 3 environmental problems that would occur if we reached our carrying capacity

Part ETo determine changes in population it is important to be able to calculate population change and growth rate.

Problem: In the year 2007 the population of a city is 305,600 people. The next year (2008) the population changed by the following numbers.

1,968 - babies are born1,012 - people died397 - people immigrated153 - people emigrated

1. What was the population change from 2007 to 2008? (use positive or negative). Show math setup:

2. What was the new population? Show math setup:

Usually we describe the Growth Rate in terms of the percent the population changed from one year to the next. For example, if a population increased from 100 people in year 1 to 115 people in year 2, growth rate is 15%.

How to calculate percent growth rate:

Population change from year 1 to year 2 = people / 1 year = x 100Initial population in year 1 people

3. Calculate percent growth rate from the previous question from 2007 to 2008

Part FBirth and death rates determine the rate of population growth. If the birth and death rates are similar, a population

experiences little or no growth. When the birth rate far exceeds the death rate, the population soars. These rates are expressed as the number of births or deaths for every 1,000 people in a given year. For instance, in 2007 the world’s birth rate was 21 per 1,000 and the death rate was 9 per 1,000. Using the formulas below, one can determine the world’s annual growth rate and the number of years it will take the population to double if the growth rate remains constant.

Intrinsic rate of natural increase = (birth rate - death rate)/10 = (21 - 9)/10 = 1.2%(This is the same as (21-9)/1000 x 100 )

Doubling Time (in years) = 70/(rate of increase) = 70/1.2 = 58.3 years

(NOTE: 70 is the approximate equivalent of 100 times the natural log of 2.)

Using the table below, determine the percentage of annual increase and the population doubling times for each country.

Percent annual natural increase (%) = (birth rate) - (death rate) 10

Doubling time (in years) = 70_______ rate of increase

Country Birth Rate (2007)

Death Rate (2007) % Annual Increase Doubling Time

United States 14 per 1000 8 per 1000

Kenya 40 per 1000 12 per 1000

Mexico 21 per 1000 5 per 1000

Bolivia 29 per 1000 8 per 1000

India 24 per 1000 8 per 1000

China 12 per 1000 7 per 1000

Japan 9 per 1000 9 per 1000

Germany 8 per 1000 10 per 1000

Russia 10 per 1000 15 per 1000

World 21 per 1000 9 per 1000

Part GHuman Population Growth: The One Child PolicyDirections: Color the statements for population control in RED and against population control in GREEN

Part HHuman Population Growth: Population StructuresDirections: read what people have to say about living in a poor, rural village in India. Color the sentences about high birth rates in RED and about short life expectancy in YELLOW. Then, read what people have to say about living in the United States and color sentences about a low birth rate in GREEN and about long life expectancy in BLUE

Part IHuman Population Growth: Population TrendsDirections: Complete the table below by sorting the factors that affect birth date and death rates into the correct columns. Some factors may fit in more than one column

Birth Rate Death Rate

High Low High Low