Population theories

2. Introduction ofIntroduction of
StudentStudentSubmitted By : Muhammad AfzalMuhammad Afzal
Roll # 30
Submitted To: Sir Zahid Mehmood
MS.c AnthropologyMS.c Anthropology
BahauddinZakariyaUniversityMultan…!BahauddinZakariyaUniversityMultan…!

3. Population growth and
MALTHUS theory

4. population
• A population is a summation of all
the organisms of the same group
or species which live in the
same geographical area and have the
capability of interbreeding

5. Thomas Malthus
• The world population in 1798
was at nine million people. We
have now passed the seven
billion mark.

6. The Core Principles of Malthus:
¤ Food is necessary for human
existence
¤ Human population tends to grow
faster than the power in the earth to
produce subsistence
¤ The effects of these two unequal
powers must be kept equal

7. Malthus recognised that population grows
at a geometric or exponential rate…
1 2 4 8 16 32
However, food only increases at an
arithmetic or linear rate…
1 2 3 4 5 6

8. and therefore he said….
War,
famine,
disease.
Malthusian Catastrophe
TIME
food population

9. CHECKS
Malthus suggested that once this ceiling
(catastrophe) had been reached, further
growth in population would be prevented.

10. 1. Negative checks (decreased
birth rate)….
• abstinence/ postponement of
marriage which lowered the fertility
rate.

11. 2. Positive checks (increased
death rate)
• events such as famine, disease, war -
increasing the mortality rate and
reducing life expectancy.

12. 'J' Curve - Population Crash
Model
What goes up, must come down. When
population exceeds carrying capacity,
population increase crashes.

13. Was Malthus right?
• There has been a population explosion
• Africa – repeated famines, wars, food
crisis, environmental degradation, soil
erosion, crop failure and disastrous
floods – so was he right?
Neo-Malthusians think so...

14. They say, he didn’t have all
the info…..
• Technological improvements which he
could not have foreseen
• The increased amount of cropland due
to irrigation
• Reduced population growth as
countries move through the DTM;
cultural decision not to have children

15. The Club of Rome
• Group of industrialists, scientists,
economists and statesmen from 10
countries
• Published ‘The Limits to Growth’ in
1972

16. Esther Boserup 1965
• Opposite to Malthus
• Boserup believed that people have the
resources of knowledge and
technology to increase food supplies.
Yummy,
food is
everywhere!

17. i.e…..
• Demographic pressure (population
density) promotes innovation and
higher productivity in use of land
(irrigation, weeding, crop
intensification, better seeds) and
labor (tools, better techniques).
• Green Revolution

18. Was she right?
Boserup argued that the changes in
technology allow for improved crop
strains and increased yields.
• GM crops
• ‘Green revolution’

19. But….
• Boserup admits overpopulation can lead to
unsuitable farming practices which may
degrade the land
• population pressure as one of the reasons
for desertification in the Sahal region (so
fragile environments at risk)
• Potential consequences of Green Revolution

20. THE END