Chapter 52
Population Ecology
AP Biology
Modified from: Kim Foglia, Explore Biology
Changes to
population size
 Adding & removing
individuals from a
population
birth
 death
 immigration
 emigration

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Growth rate
 Exponential growth

characteristic of a population without limiting
factors
 ex. introduced to a new environment
Whooping crane
coming back from near extinction
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African elephant
protected from hunting
Carrying capacity
 Can populations continue to
grow exponentially?


of course NOT!
what sets limit?
 resources, predators, parasites
 Carrying Capacity (K)

maximum population
size that environment
can support with no
degradation of habitat
 not fixed; varies with
changes in resources
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Model of growth
Decrease in rate of growth as reach carrying capacity
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Different life strategies
 K-selection
 r-selection
K-selection
mortality constant
r-selection
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Reproductive strategies
 K-strategy

have few offspring &
invest a lot of energy in
raising them to
reproductive age
 primates
 coconut
 r-strategy

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have many offspring &
invest little in their
survival
 insects
 dandelion & other weeds
Predator – prey interactions
 Population cycles
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Age structure
 Relative number of individuals of each age
What do the data imply about population growth in
these countries?
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Human population
20056 billion
What factors have contributed to this
exponential growth pattern?
Is the human
population reaching
carrying capacity?
1650500 million
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