UNIT
5 Population
Dynamics
On Easter Sunday 1722, Jacob Roggeveen
discovered a 650-km^2 island in the Pacific Ocean,
3700 km from the nearest continent. He described
it as a dry wasteland with no trees or bushes over
3 m high or native animals larger than an insect.
Evidence suggests that humans arrived on Easter
Island about A.D. 400, having come from Polynesia.
With them came chickens and rats, which
reproduced rapidly. Much of the island was
forested; huge palms and a diversity of other trees
provided food, wood for timber and dugout canoes,
and fibre for rope. The human population grew
rapidly and developed an elaborate culture,
sufficiently organized to permit quarrying,
transportation, and raising hundreds of enormous
statues to honour ancestors.
Gradually, things changed. By 1400, trees were
extinct on the island. Without large canoes, the
islanders had to rely on near-shore fish, as well
as land birds. As food supplies dwindled, society
broke down. Warring tribes pulled down most of
the statues. Eventually the human population fell
to about 1000, one tenth its peak size. Perhaps the
experience of the Easter Islanders can provide
lessons for us currently living on the “island”
known as Earth.Unit
Contents
Chapter 13
Ecological
Principles........
Chapter 14
Population
Ecology.........
Chapter 15
Human Ecology....
Unit Issue
Analysis.........^538502464428426
Unit
Preview
In this Unit, you will
analyze the components of
population growth and
explain the factors that
affect the growth of
populations,
investigate and evaluate
populations, their
interrelationships, and
their effect on the
sustainability of life
on Earth, and
evaluate the carrying
capacity of Earth and
relate it to the growth of
populations, consumption
of natural resources, and
technological advances.Human activity combined with increased drought can turn
rich fertile land into deserts. The understanding of ecology
and its effect on the environment are critical to preserving
the biosphere.Read pages 538–539
before beginning this unit.
Choose a country from the
list or select one you
would like to investigate.
Begin research to identify
the country’s most pressing
environmental issue.
Collect information on the
issue and its effect on
human populations.UNIT ISSUE PREP