Population ClockPopulation Clockhttp://www.poodwaddle.com/clocks/worldclock/

The Water Lily StoryThe Water Lily StoryThe 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?

.Lily Pond – Day 1

.

Lily Count:

1

.Lily Pond – Day 2

.

Lily Count:

2

.Lily Pond – Day 3

.

Lily Count:

4

.Lily Pond – Day 4

.

Lily Count:

8

.Lily Pond – Day 5

.

Lily Count:

16

.Lily Pond – Day 6

.

Lily Count:

32

.Lily Pond – Day 7

.

Lily Count:

64

.Lily Pond – Day 8

.Lily Count:

128

.Lily Pond – Day 9

.Lily Count:

256

.Lily Pond – Day 10

.Lily Count:

512

.Lily Pond – Day 11

.Lily Count:

1,024

.Lily Pond – Day 12

.Lily Count:

2,048

.Lily Pond – Day 13

.Lily Count:

4,096

.Lily Pond – Day 14

.Lily Count:

8,192

.Lily Pond – Day 15

.Lily Count:

16,384

.Lily Pond – Day 16

.Lily Count:

32,768

.Lily Pond – Day 17

.Lily Count:

65,536

.Lily Pond – Day 18

. Lily Count:

131,072

.Lily Pond – Day 19

Lily Count:

262,144.05 % covered

Lily Pond – Day 20

Lily Count:

524,288.10 % covered

Lily Pond – Day 21

Lily Count:

1,048,576.20 % covered

Lily Pond – Day 22

Lily Count:

2,097,152.39 % covered

Lily Pond – Day 23

Lily Count:

4,194,304.78 % covered

Lily Pond – Day 24

Lily Count:

8,388,6081.56 % covered

Lily Pond – Day 25

Lily Count:

16,777,2163.13 % covered

Lily Pond – Day 26

Lily Count:

33,554,432

Pond is 1/16th

covered

Lily Pond – Day 27

Lily Count:

67,108,864Pond is 1/8th

covered

Lily Pond – Day 28

Lily Count:

134,217,728

Pond is 1/4th

covered

Lily Pond – Day 29

Lily Count:

268,435,456

Pond is 1/2 covered

Lily Pond – Day 30

Lily Count:

536,870,912

Pond is completely covered

Characteristics of PopulationsCharacteristics of Populations Geographic Geographic

DistributionDistribution

DensityDensity

Growth rateGrowth rate

Age structureAge structure

Area inhabited by a Area inhabited by a populationpopulation

The # of individuals The # of individuals per unit areaper unit area

Rate at which a Rate at which a population changes population changes sizesize

Different ages of the Different ages of the organisms in a organisms in a populationpopulation

Population DensityPopulation Density The number of individuals per unit areaThe number of individuals per unit area

Population Density

Cactus: small #’s

Low density

Shrubs: higher #’s

High density

Population GrowthPopulation GrowthFactors that affect population size:Factors that affect population size: Birth RateBirth Rate

Death RateDeath Rate

ImmigrationImmigration

EmigrationEmigration

• the amount of births the amount of births

• the amount of deathsthe amount of deaths

• moving into an areamoving into an area

• moving out of an areamoving out of an area

How is the Population Affected?How is the Population Affected?Increase or DecreaseIncrease or Decrease

birth rate & birth rate & death rate death rate

birth rate & birth rate & death rate death rate

immigrants & immigrants & emigrants emigrants

immigrants & immigrants & emigrants emigrants

DecreaseDecrease

IncreaseIncrease

DecreaseDecrease

IncreaseIncrease

Exponential GrowthExponential Growth Will occur under IDEAL Will occur under IDEAL

conditionsconditions1.1. unlimited resourcesunlimited resources2.2. no predatorsno predators3.3. no diseaseno disease4.4. plenty of spaceplenty of space

Produces a J – shaped CurveProduces a J – shaped Curve

Logistic CurveLogistic CurveS- CurveS- Curve

In ecosystems:In ecosystems:• Resources are limitedResources are limited• PredatorsPredators• DiseaseDisease

The growth of populations slows or stops The growth of populations slows or stops (actually averages out to a steady size)(actually averages out to a steady size)

• Birth rate = death rateBirth rate = death rate• Immigration = emigrationImmigration = emigration

Leveled-off population reached its Leveled-off population reached its carrying capacitycarrying capacity

Carrying CapacityCarrying Capacity The largest number of organisms The largest number of organisms

that a given ecosystem can supportthat a given ecosystem can support

Logistic CurveLogistic CurveS-CurveS-Curve

WaynesWaynes world 2 clip world 2 clip