1. Populations Chapter 5 U.S. 303,558,100 World 6,636,447,956

2. What Affects Population Size? 3 Imagine that each of the three different colors of paper clips that you have in an envelope represents a different species organisms. Working with a partner and using the envelopes of paper clips that you both have, answer the following questions.

3. Answer these... 1.How many populations of organisms do you have in your envelope? In your partner’s envelope? 2.Choose one of the populations in one of the envelopes. How might this population grow in size? 3.How might this same population decrease in size?

4. Characteristics of Populations Geographic Distribution Density = # of individuals unit area Growth Rate

5. Population Density How many people in the classroom? What is the room’s area? *Area = ? How many people in the room per square meter?

6. Population Growth Exponential Growth Logistic Growth Characterized Represented by by Falling growth rate S-shaped curve Limits on growth No limits on growth J-shaped curve Constant growth rate Unlimited resources Characterized by Which results in Represented by

7. Factors Affecting Population Growth ↑ Population Immigration ↓ Population Natality Mortality Emigration

8. *At the beginning of the year, the King Penguin population was 1200 At the end of the year it was 1600. What was the population’s growth? Suppose 250 chicks died during the year, what was the population’s growth? Suppose that 200 adult penguins also died during the year. What was the population’s growth?

9. Logistic vs. Exponential Number of Yeast Cells Time (hours) Carrying capacity With unlimited resources Growth is at a constant rate Growth stops/slows following exponential growth

10. Name That Resource! A situation that causes the growth of a population to decrease is called a limiting factor. Some limiting factors depend on the size of the population. Other limiting factors affect all populations in similar ways, regardless of the population size.

11. 1.Imagine a small island that has a population of five rabbits. How might each of the following factors affect the rabbit population? a. climate b. food supply c. predation 2.Now imagine another small island that has a population of 500 rabbits. How would the same factors affect this population? 3Which of the factors depend on population size? Which factors do not depend on population size?

12. Population Size

13. Density-Dependent Limiting Factors Exponential growth Steady population size Peak population size Rapid decline Steady population size Ex: competition, predation, parasitism, disease

14. Wolf and Moose Populations on Isle Royale Moose Wolves 60 50 40 30 20 10 0 195519601965197019751980198519901995 2000 1600 1200 800 400 0 2400

15. How Fast Are We Growing? Until about 500 years ago, the world’s human population remained fairly stable. Then, as advances in medicine, agriculture, and technology occurred, the human population began growing very rapidly. Today, the world’s human population is greater than 6 billion people, and it continues to grow, but at a slower rate.

16. Agriculturee begins Plowing and irrigation Bubonic plague Industrial Revolution begins Historical Overview

17. Patterns of Population Growth Demography: The study of human populations that looks at characteristics of human populations and attempts to explain how they will change over time Demographic Transition –Over the last 100 yrs population growth has slowed in U.S., Japan, much of Europe

18. Advances in nutrition, sanitation, medicine etc. begin the demographic transition. Transition complete when cbr falls to meet the cdr and growth stops.

20. Age Structure Males Females Prediction: slow steady growth rate Prediction: population will double in ~30 yrs