Why not stop population? : Why not stop population? Dr Subroto Biswas
BBIPL
Slide 2 : A population
Population….. : Population….. A group
Individuals of same species
Living in a well defined geographical area
Share or compete for similar RESOURCES
Potentially interbreed
Sexually reproducing (or even asexually )
Slide 4 : Examples...
People of Punjab
Slide 5 : Teakwood trees in a forest
Slide 6 :
Attribution of a population : Attribution of a population Births
Deaths : Deaths
Sex ratio : Sex ratio
Population size (population density) : Population size (population density)
Slide 11 : Habitat
Climate
competition
Food resources/predation : Food resources/predation
Employment/ : Employment/
Unemployment : Unemployment
Enemies : Enemies
Diseases : Diseases More than 330 million people are infected with a sexually transmitted disease each year
Over 52 million women in Africa, Asia and Latin America deliver their babies each year without a nurse, midwife or a doctor present : Over 52 million women in Africa, Asia and Latin America deliver their babies each year without a nurse, midwife or a doctor present
Demography : Demography The statistical study of human population
Population density = number of individuals in a region/unit time : Population density = number of individuals in a region/unit time Natality (B) Mortality (D)
Population density (N)
Immigration (I) Emmigration (E)
At a time ‘t’, population density = N
At a time ‘t + 1’, now population density..
Nt+1 = Nt + [(B+I) – (D+E)
Slide 20 : Population density (N) = 19 persons /sq. km
‘N’ of India is more than 30 persons/sq. km.
Which is MOST thickly populated country ? : Which is MOST thickly populated country ?
Carrying Capacity : Carrying Capacity The maximum number of individuals that can be sustained in a particular environment
What is the carrying capacity of the earth ? : What is the carrying capacity of the earth ? 50 billion
Factors affecting a population(Forces that determine animal population input and output) : Factors affecting a population(Forces that determine animal population input and output) NATALITY (birth rate)
Number of individuals born per unit
Slide 25 : MORTALITY (death rate)
Number of individual dying out per unit time
Slide 26 : EMMIGRATION (out)
Number of individual going out of a population
Slide 27 : IMMIGRATION (in)
Number of individual being added to a population
POPULATION GROWTHS : POPULATION GROWTHS Two basic growth models are predicted
For growth of population in unit time
EXPONENTIAL GROWTH
=Shows “J” shaped growth phase
In predator free zone
LOGISTIC GROWTH
=Shows SIGMOID or “S” shaped growth curve (or Verhulst-Pearl logistic growth cure)
LOGISTIC GROWTH = Sigmoid or ‘S’ growth curve : LOGISTIC GROWTH = Sigmoid or ‘S’ growth curve Comprises..
LAG PHASE
Early phase
Little or no growth (stabilisation)
POSITIVE ACCELERATION PHASE
Faster growth
EXPONENTIAL PHASE
Middle phase
Rapid growth
That is geometric phase
NEGATIVE ACCELERATION PHASE
Growth slows down
STEADY PHASE
Last phase of ZERO GROWTH
New cells = Dying cells
Some facts : Some facts India has one doctor for 5800 people as compared to Japan’s one doctor for 900 people
Slide 31 : Incidentally Japan has higher literacy rate than even US
Slide 32 : Growth rate
= birth rate - death rate per thousand per year
Vital Index : Vital Index The ratio of birth rate and death rate is called vital index
VI = Birth rate X 100
Death rate
Vital index helps to understand the rate of growth of population
Slide 34 :
Slide 35 : Growth rate of India’s population..23.50%
Slide 36 : Highest density in India:
Kerala(655)
West Bengal (615)
Slide 37 : Lowest density:
1.Arunachal Pradesh (10)
2. Mizoram (33)
Slide 38 : Asian population = 60 % of he world’s population
World’s population is increasing by 2 persons/second : World’s population is increasing by 2 persons/second
Slide 40 : India is 7th in terms of land that is, 2.42% of total land on earth
But India is 2nd in terms of population, that is, 15.6 % of total world’s population
Slide 41 : India’s population is 3 times than that of USA 6 times than that of Japan 21 time than that of Canada
Slide 42 : The year 1921 is called BIG DIVIDE as India’s population started to increase rapidly
Slide 43 : Indian state, Uttar Pradesh has the largest population = 138.7 millions
Slide 44 : Sikkim has the smallest population = 4 lakhs
More females than males : More females than males Only Kerala
(1040 female /1000 males)