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A Brief Overview ofJAVADemography |
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Why are human populations in Africa growing so rapidly,
even though life expectancy is shorter than in most other parts of the world? Why
do rapidly growing populations have such a large proportion of children? Why is the
population of China still growing, even though the Chinese government is enforcing
a ìone-child per coupleî population policy? What conservation policies are most likely
to be effective at preventing extinctions of endangered species such as killer whales,
spotted owls, or cheetahs?
These are a small sample of the kinds of questions that can be addressed by JAVA
Demography, a computer program that simulates exponential population growth.
By manipulating values for mortality rates, fertility rates, and initial population
characteristics, and then using the simulation to see how population characteristics
change through time, users of Demography can investigate important questions
in population biology, develop a deeper understanding of fundamental population concepts,
and explore issues related to population policy.
A key feature of Demography is the easy-to-use interface that allows you to
rapidly and intuitively alter population characteristics and to instantaneously see
the effects of your alterations. For example, changing the mortality rate of a particular
age group, such as 20-25 year-olds, can be done by simply manipulating a point on
a graph using the mouse. As soon as you release the mouse button, Demography
will recalculate important population statistics, such as longevity (mean life expectancy)
or doubling time. If the simulation is running, you will immediately see the effect
of your changes on the growth of the population and on the shape of its age pyramid.
Demography is designed to make it easy for you to creatively explore and experiment.
Just as importantly, it is designed to help you organize your explorations and keep
track of your experiments. You may stop a simulation at any time and mark your place
so that you can return to it later to make comparisons, to perform controlled experiments,
or simply to refresh your memory.
We hope that you find Demography to be an interesting and productive way to
learn about the dynamics of populations. In any case, we would like to hear from
you (both students and faculty) about your experiences with the program. We are particularly
interested in knowing the kinds of issues that you have explored, how Demography
helped, and what kinds of limitations or problems you encountered. Please contact
the Biology Software Lab, or provide feedback
using our feedback report forms.
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Copyright © 1999 University
of Oregon
All rights reserved.
The software described in this document is furnished under a license agreement. The
software and/or manuals may be used or copied only in accordance with the terms of
this agreement.
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