Population Pyramids: Shapes - PowerPoint Presentation

1. Population Pyramids: ShapesSession4Shape: TriangularGrowth: Fast Shape: Extended TriangleGrowth: Moderate Shape: ColumnGrowth: SlowShape: Reduced PentagonGrowth: Shrinking

2. Thomas Malthus – 1798 wrote “Essay on the Principle of Population” Theory: People need food to survive and have natural desire to reproduceFood production increases arithmetically and population increases exponentiallyConclusion:Predicted population growth would eventually outpace people’s ability to produce food leading to mass starvation and famineTimeResources NeededToday1 person-1 unit of food25 years from now2 persons-2 units of food50 years from now4 persons- 3 units of food75 years from now8 persons- 4 units of food100 years from now16 persons-5 units of foodMalthus and OverpopulationSession4

3. Neo-Malthusians argue that 3 characteristics of recent population growth makes Malthus’ argument even more frighteningSustainability: As the world approaches 10 billion people, ecological problems will make food demand difficult to meetIncreasing Per Capita Demand: Amount of food per person is rising MDC citizens consume eight times the amount someone in an LDC consumesNatural Resource Depletion: Over-consumption of resources other than food may lead to an insufficient supply when the population hits 10 billionPaul Erlich – most prominent neo-Malthusian. Wrote “Population Bomb”Neo-MalthusiansSession4

4. The disastrous end to humanity predicted by Malthus did not occur according to his critics for the following reasons:Invention: Food production increased because of tractors, artificial fertilizer, pesticides, irrigation techniques, plant and animal hybridization, refrigeration and canningFamily Planning: Malthus did not foresee family planning and birth control and leading to a drop in CBR and NIRScarcity/Distribution: Malthus did not recognize that famine is usually NOT related to a lack of food but to unequal distribution of foodMalthus and OverpopulationSession4

5. Carrying Capacity: The number of people a given area can maintainIf surpassed, the population must decline unless the carrying capacity is raised. Overpopulation, therefore, implies a breach of an area’s carrying capacity, due to…Over consumption of resourcesInefficient allocation of goodsUnsustainable land useMDC’s blame LDC’s for having too many babies while LDCs blame MDCs for consuming disproportionate share of world’s resourcesCarrying CapacitySession4

6. The stages of the Epidemiological Transition Model follows the same path as the Demographic Transition Model.Stage 1: Pestilence and FamineInfectious diseases run rampant killing a large number of the populationStage 2: Receding PandemicsImproved sanitation, nutrition, medicine decreases spread of infectious diseasesStage 3: Degenerative and Human Created DiseasesFewer deaths from infectious diseases but an increase in chronic disease associated with aging (heart disease and cancer)Stage 4: Delayed Degenerative Diseases Degenerative diseases linger but life expectancy is extended through medical advances (bypass, radiation, chemo, etc.)Stage 5?: Reemergence of Infectious and Parasitic DiseasesEvolution of new strains of bacteria (TB, polio, malaria) that are diffused faster due to globalization with a select few able to pay for the treatmentEpidemiological Transition ModelSession4

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8. VideoDirections:There is no video guide, but students are expected to write down 5 impressions and/or questions that they have from the documentary.Session2China’s Lost Girlshttp://www.snagfilms.com/films/title/chinas_lost_girls