HOW POPULATIONS GROW

1. HOW POPULATIONS GROW

2. Population Clock http://www.poodwaddle.com/clocks/worldclock/

3. The Water Lily Story The Anchor Bay High School pond has one water lily leaf floating on the surface. The lily population will double in size every day if left unchecked. The water lilies will smother the pond in 30 days, effectively killing all other living things in the water. At what point should you concern yourself with cutting back the lily plants? When the pond is 1/8th covered, one-fourth covered, or one-half covered?

4. Lily Pond – Day 1 . . Lily Count: 1

5. Lily Pond – Day 2 . . Lily Count: 2

6. Lily Pond – Day 3 . . Lily Count: 4

7. Lily Pond – Day 4 . . Lily Count: 8

8. Lily Pond – Day 5 . . Lily Count: 16

9. Lily Pond – Day 6 . . Lily Count: 32

10. Lily Pond – Day 7 . . Lily Count: 64

11. Lily Pond – Day 8 . . Lily Count: 128

12. Lily Pond – Day 9 . . Lily Count: 256

13. Lily Pond – Day 10 . . Lily Count: 512

14. Lily Pond – Day 11 . . Lily Count: 1,024

15. Lily Pond – Day 12 . . Lily Count: 2,048

16. Lily Pond – Day 13 . . Lily Count: 4,096

17. Lily Pond – Day 14 . . Lily Count: 8,192

18. Lily Pond – Day 15 . . Lily Count: 16,384

19. Lily Pond – Day 16 . . Lily Count: 32,768

20. Lily Pond – Day 17 . . Lily Count: 65,536

21. Lily Pond – Day 18 . . Lily Count: 131,072

22. Lily Pond – Day 19 . Lily Count: 262,144 .05 % covered

23. Lily Pond – Day 20 Lily Count: 524,288 .10 % covered

24. Lily Pond – Day 21 Lily Count: 1,048,576 .20 % covered

25. Lily Pond – Day 22 Lily Count: 2,097,152 .39 % covered

26. Lily Pond – Day 23 Lily Count: 4,194,304 .78 % covered

27. Lily Pond – Day 24 Lily Count: 8,388,608 1.56 % covered

28. Lily Pond – Day 25 Lily Count: 16,777,216 3.13 % covered

29. Lily Pond – Day 26 Pond is 1/16th covered Lily Count: 33,554,432

30. Lily Pond – Day 27 Lily Count: 67,108,864 Pond is 1/8th covered

31. Lily Pond – Day 28 Lily Count: 134,217,728 Pond is 1/4th covered

32. Lily Pond – Day 29 Lily Count: 268,435,456 Pond is 1/2 covered

33. Lily Pond – Day 30 Pond is completely covered Lily Count: 536,870,912

34. Characteristics of Populations • Area inhabited by a population • The # of individuals per unit area • Rate at which a population changes size • Different ages of the organisms in a population • Geographic Distribution • Density • Growth rate • Age structure

35. Population Density • The number of individuals per unit area

36. Population Density Cactus: small #’s Low density Shrubs: higher #’s High density

37. Birth Rate Death Rate Immigration Emigration the amount of births the amount of deaths moving into an area moving out of an area Population GrowthFactors that affect population size:

38.  birth rate &  death rate  birth rate &  death rate  immigrants &  emigrants  immigrants &  emigrants Decrease Increase Decrease Increase How is the Population Affected?Increase or Decrease

39. Exponential Growth • Will occur under IDEAL conditions • unlimited resources • no predators • no disease • plenty of space • Produces a J – shaped Curve

41. Logistic CurveS- Curve • In ecosystems: • Resources are limited • Predators • Disease • The growth of populations slows or stops (actually averages out to a steady size) • Birth rate = death rate • Immigration = emigration • Leveled-off population reached its carrying capacity

42. Carrying Capacity • The largest number of organisms that a given ecosystem can support

43. Logistic CurveS-Curve

46. Waynes world 2 clip