1. Chapter 5 Populations

2. Biotic Potential: The size a population would reach if all offspring were to survive and reproduce

3. Conditions have to be ideal- enough food and living space

4. Population Density- Number of individuals in an area What Determines density and distribution?

6. Geographic Distribution- range- the area the population inhabits

7. Population Growth Affected by -Birth rate (natality) -Death rate (mortality) -Immigration- entering an area -Emigration- leaving an area

8. Populations increase if births exceed deaths and immigration exceeds emigration

9. Exponential Growth Exponential Growth occurs when the individuals in a population increase at a constant rate Look at graph on p.121

10. -under ideal conditions -population grows slowly at first -rises to an infinitely large size -J-shaped curve

12. Logistic Growth Logistic growth occurs when a population’s growth slows or stops following a period of exponential growth. S-shaped curve-graph levels off

13. Carrying capacity- Usually population fluctuates around this point- s-shape Look at graph on p. 122

15. Carrying Capacity The number of individuals an area can support without ruining the area.

16. Limiting Factors Something that causes population growth to decrease Density dependent Density independent

17. Density- Dependent Factors Limit a population when the number of individuals reach a certain level Competition for food, water, space, sunlight, etc.

18. Predation Parasitism + disease

19. Wolf/Moose graph

20. Density -Independent Factors Affect all populations regardless of size Weather, natural disasters, seasonal change, human interventions (dams,logging, housing developments)

21. Populations usually decrease dramatically after such an event Can be permanent + cause extinction

22. Human Population Growth Slow growth historically Now, exponential growth- 6-7 billion Current World Population

23. Some countries have higher growth rates than others

24. Demographic Transition Dramatic change in birth and death rates Nutrition, medicine, clean water supplies increase survival rates

25. Some countries, population stabilizes, but for a while, births may exceed deaths

26. Age diagram

27. In some cases, populations may even decrease- U.S., Japan, Europe

28. Some countries are still growing exponentially Parts of Africa, Mexico, India

29. Many young people, of an age where they will still be having children

30. 9 billion predicted by 2050 What will stop/slow the growth?