Human Population
Denica Thomas
Define Age/Sex Structure.
 How to construct and interpret an Age/Sex
Structure.
 Uses of Age/Sex Structure Diagrams.

The
age/sex structure is also
called the Population Pyramid.
This Structure or Pyramid is a
graphic way to show the age and
sex composition of a population.
The sum of all age and sex
groups equals 100 percent of the
population.
 With
age and sex distribution data from a
certain population, it is easy to construct an
age structure diagram. Once the diagram is
constructed, one can clearly see if the
population will grow, decline, or experience
no noticeable change in its population
number.
 for
example, if the diagram shows a
pyramidal shape, then one can expect a
rapid rise in population. If the diagram shows
a generally straight up and down shape
except for the older age groups, a stable
population is thus revealed. If the diagram
shows a top-heavy shape, then a decline is
forecast for that population.
Scotland Age/Sex structure
diagram(pyramidal Shape)
Japan Age/ Sex structure(Top Heayy
shape)
 The
developing countries have a
population structure that resembles a
pyramid with a broad base of young and a
small apex of old. Sudan in 1995 is an
example of a pyramid for a developing
country.
 The
developed countries are beginning to
lose their "pyramidal" shape as they
become more straight up and down with
almost equal numbers of people in
adjacent age groups until the ages of high
death rates begin after age 65. United
States in 1995 is an example of a pyramid
for a developed country.
 Population
pyramids can be used to find
the number of economic dependents
being supported in a particular
population. Economic dependents are
defined as those under 15 (children who
are in full time education and therefore
unable to work) and those over 65 (those
who have the option of being retired).
 In
many countries, the government plans
the economy in such a way that the
working population can support these
dependents. Age pyramid has similar uses
to population pyramid.
 Population
pyramids can be used to
observe the natural increase, birth, and
death rate.