Download - Chapter 4 Biology
Chapter 4Chapter 4
Population BiologyPopulation Biology
How do Populations How do Populations Grow???Grow??? Any population, when given Any population, when given
unlimited amounts of resources unlimited amounts of resources will grow will grow exponentiallyexponentially. .
Types of GrowthTypes of Growth
Logistics growth: Flattened S-Logistics growth: Flattened S-shaped curveshaped curve
Exponential Growth: J-shaped Exponential Growth: J-shaped curvecurve
Predator-Prey: Zig-ZagPredator-Prey: Zig-Zag
Exponential GrowthExponential Growth
Begins slowly, then increases rapidly Begins slowly, then increases rapidly over a short amount of time.over a short amount of time.
Logistic Growth CurveLogistic Growth Curve
Begins Begins slowly, then slowly, then grows grows exponentiallexponentially for a time, y for a time, then begins then begins to level out.to level out.
Flattened S Flattened S shapeshape
What Keeps What Keeps Populations under Populations under control???control???
Limiting Factors !!Limiting Factors !!
2-Types2-Types
Density Dependent Density Dependent Limiting FactorsLimiting Factors Factors that have an increasing Factors that have an increasing
effect as the population effect as the population increases.increases.
Ex: Disease, parasites, predators, Ex: Disease, parasites, predators, competition for food…competition for food…
Density Independent Density Independent FactorsFactors Factors that Factors that
affect affect populations populations regardless of regardless of their density. their density. (abiotic)(abiotic)
Ex: hurricanes, Ex: hurricanes, floods, drought, floods, drought, fire…fire…
Predator-Prey RelationshipPredator-Prey Relationship
Predators and their prey experience cycles in Predators and their prey experience cycles in population growth.population growth.
Carrying CapacityCarrying Capacity
The maximum The maximum number of number of individuals an individuals an area can sustain.area can sustain.
The blue dotted The blue dotted line represents line represents the carrying the carrying capacity.capacity.
2-Life History Patterns2-Life History Patterns
1. Rapid1. Rapid 2. Slow2. Slow
Rapid Life HistoryRapid Life History
Small body sizeSmall body size Mature rapidlyMature rapidly Reproduce earlyReproduce early Short life spansShort life spans
Slow Life HistorySlow Life History
Large body sizeLarge body size Mature slowlyMature slowly Reproduce slowlyReproduce slowly Longer life spansLonger life spans
Three patterns of dispersal are Three patterns of dispersal are randomrandom, , clumpedclumped, and , and uniformuniform..
Density factors and population growthDensity factors and population growth
Random Clumped Uniform
Human Population Human Population GrowthGrowth
DemographyDemography: the study of human : the study of human population sizepopulation size, , density and density and
distributiondistribution, , movementmovement, and its , and its birth birth and death ratesand death rates..
Human Population Human Population Growth…Growth…
Age Structure for Age Structure for Human Population Human Population GrowthGrowth
Population Distribution Per Age Range for Several Countries
Stable growth Rapid growth Slow growth
Population (percent of total for each country)
Male
Female
Reproductive years
Age