Activity 14 Investigating Population Growth Rates Get Started

Activity 14 Investigating Population Growth Rates

Get Started � What ecological conditions might promote growth of a population (rabbits for example) � What ecological conditions might limit population growth? Activity 14: Investigating Population Growth Rates

Introduction Read the introduction � Look at zebra mussel graph… � What does the graph tell you about the population? � What factors do you think contribute to this? � Know these vocabulary terms: ◦ carrying capacity ◦ Population growth rate ◦ Zero population growth rate Activity 14: Investigating Population Growth Rates

Introduction � Carrying capacity is the size of a population an ecosystem can support based on the resources available and the other species present in the ecosystem. Zero Growth Rate: population NOT growing…remains the same Population growth rate describes the change in a population over specified intervals of time Activity 14: Investigating Population Growth Rates

Avril Gulf Seal Population Activity 14: Investigating Population Growth Rates

Challenge � How do changing variables alter population growth rates and ecosystem carrying capacities? Activity 14: Investigating Population Growth Rates

LIMITING FACTORS � Conditions that limit a population from growing larger � Make a list in your notes Activity 14: Investigating Population Growth Rates

LIMITING FACTORS � DENSITY DEPENDENT ◦ Factors where the effects on the size or growth of a population vary with the density of the population itself ◦ EXAMPLES? � DENSITY INDEPENDENT ◦ limit the size of a population regardless of the density of the population ◦ EXAMPLES? POPULATION DENSITY Number of individuals per area Activity 14: Investigating Population Growth Rates

Procedure AVRIL SEAL POPULATION � View population graphs and answer questions � Complete the activity on the Avril Seal Population � Population equation: BIRTHS – DEATHS 1000 Activity 14: Investigating Population Growth Rates

POPULATION GROWTH PATTERNS � View various population growth graphs � Draw each in your notes � Identify and describe the growth for each Activity 14: Investigating Population Growth Rates

Linear Growth Curve Population is growing the same amount at regular intervals EX: a population that increases by 2 individuals each month Activity 14: Investigating Population Growth Rates

Exponential Growth: J-Curve Rate of increase is continually rising Resources are plentiful Few/no predators Little disease Low death rate Activity 14: Investigating Population Growth Rates

But no population can continue to grow forever… Carrying Capacity: S-Curve Populations will eventually run out of resources…fail to find mating partners; or other factors such as disease or predators will cause a population to reach its carrying capacity Population will remain relatively stable …but there may be flutuations Activity 14: Investigating Population Growth Rates

Population Crash Rapid decrease in population What factors could cause this to happen in a population? Population decline is inevitable when a population exceeds its carrying capacity Activity 14: Investigating Population Growth Rates

Activity 14: Investigating Population Growth Rates

WORLD POPULATION GROWTH � Watch this video to view world population growth over past 2000 years Activity 14: Investigating Population Growth Rates

Procedure OBSERVING POPULATION GROWTH Using the data provided…prepare a graph showing the growth of bacteria Using the data provided…prepare a graph showing the growth of the world population Label each graph: LAG PHASE… EXPONENTIAL GROWTH…STABILITY… DEATH PHASE Answer questions Activity 14: Investigating Population Growth Rates

Analysis 7 � Look at the population graph for the fish population shown below. How would you describe the growth rate? Is this population sustainable? Activity 14: Investigating Population Growth Rates

Analysis 8 � Examine the data in the Global Human Population graph provided below. Based on your work in this activity, how would you describe the global human population growth rate? Explain your reasoning. Activity 14: Investigating Population Growth Rates

Revisit the Challenge � How do changing variables alter population growth rates and ecosystem carrying capacities? Activity 14: Investigating Population Growth Rates

Key Vocabulary � carrying capacity � density-dependent factors � density-independent factors � population growth rate Activity 14: Investigating Population Growth Rates