2. Statistical study of human population.
 It can be a very general science that can
be applied to any kind of dynamic
human population, that is, one that
changes over time or space.
 It encompasses the study of the size,
structure and distribution of these
populations, and spatial and/or
temporal changes in them in response
to birth, migration, aging and death.

5. Fertility - Refers to the actual no. of children
born to a woman or group of women. A simple
way to measure fertility is to get the crude birth
rate: the numbered of registered birth’s per 1,000
of the population in a given area at a specified
time.
CBR= Registered number births in a yr. X 1,000
Total mid year population

6. Mortality. - refers to the no. of deaths per
1,000 of the total mid-year population in a
particular place at a specified time, and is
measured by the crude death rate.
CBR= Registered number of death a yr. X 1,000
Total mid-year population
Life Expectancy – refers to the average number
of years a person can expect to live at the time of
birth.

7. Migration – another factor w/c affects
population change.
Push – refers to the unfavorable, unattractive
condition which impel a person or group of
persons to move at an area.
Natural Disasters – such as famines, floods
or volcanic eruption, political repressions;
religious or racial discrimination or
persecution; or internal disorders such as war
and other forms of conflict.

8. Pull – refers to the favorable condition or
attractions of a locality which lure a person or
group of persons to move in to that area. Among
these are favorable climate, employment
opportunities, peace and order, political and
religious freedoms, respect for human rights, better
recreational & cultural facilities.
Internal Migration – is the spatial movement of
a person or groups of persons within a country or
specified territory, more or less for permanent
residency.

9. Immigration – when one enters the country
of destination.
Emigration – when one leave’s one country
in order to move into another.

10. Overall the world’s popular grew slowly until
about 1850 – so slowly, in fact the several
hundred thousand years were needed for the earth
to reach one billion ( Wilford, 1981). The earth’s
second billion were added by 1930 due to
advances in medicine, farming transportation.
Population is estimated to cross the 6 billion
thresholds in October 1999.

11. Malthusian Theory – the English scholar
Thomas Maltus (1766 – 1834) whose theories
appeared in 1798 in “An Essay on the
Principle of Population”, theorized
pessimistically that population was
uncontrollable and that it would, at a future
date, reach and then exceed a level at which
the planet could sustain in incredible high
population numbers.

12. Demographic Transition Theory – the
concept demographic transition refers to the three
char. stages of the population dynamics for
societies under going industrialization. In the first
stage, which is character of preindustrial societies
both the birth rate and the death rate are high
and relatively stable. The second stage is a
transitional one, the birth rate remains but the
death rate declines as nutrition, health and
sanitation improve. Stage three, both the birth
rate and the death rate are low and in balance
again.