Transcript Introduction to Population Dynamics

Populations
Introduction to Population Dynamics
I. Populations
A. What is a population? A group of organisms of the same species
that interbreed and live in the same place at the same time.
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II. Population Growth
A. How are populations affected by resources available in the
environment?
1. Resources determine how a given population will grow.
B.
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3.
a. Populations grow when birth rate + immigration rate (# of
organisms moving into a population) > death rate +
emigration rate (# of organisms moving out of a population)
III. Limiting Factors
A.
1. Resources, nutrients (matter) and energy in short supply, limit
how large a population can grow, therefore resources can be
limiting factors.
B.
1. Density-dependent limiting factors control population size when a
population is large and crowded.
a. examples: competition, predation, parasitism and crowding
2. Density-independent limiting factors control population size
regardless of whether a population is large or small.
a. examples: natural causes such as geothermal activity, extreme
weather
IV. Carrying Capacity & Population Growth
A. Carrying Capacity- the number of individuals in a
population that can be sustained indefinitely in a given
ecosystem.
-very difficult number to specify
B.
C.
D.
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A.
B.
C.