Population MAJOR Population Clusters: Ecumene: The portion of Earth’s surface occupied by permanent human settlement. Why do people live in particular areas? Moderate climatenot too hot, too cold, not too dry, or too wet Proximity to water and other large landmasses. Industrial revolutioncaused a population shift during the 1700’s and 1800’s. The big shift is from rural to urban areas. Important Fact: May, 2007, the first time in world history where more people were living in an urban area. Definition of densities: Arithmetic-total number of objects in an area. Physiological-number of people supported by a unit of arable land. Agricultural-farmers per unit of arable land. Density processing activity: Write the following figures down in your notes: – US population: 314,000,000 – Total land area: 3,718,694 – Arable land as a percentage of total land area: 18.01% – Farmers as a percentage of the population: 0.7% Work with a partner to compute the following: Arithmetic density (Divide the population by land area.) Physiological density Agricultural density Natural Increase: CBR (crude birth rate)-total number of live births in a year for every 1,000 people alive in a society. CDR (crude death rate)-total number of deaths in a year for every 1,000 people alive in a society. NIR (natural increase rate)-the percentage by which a population grows a year.(CBRCDR=NIR) per 1,000 and converted to a percentage. Doubling time-the number of years it takes a population to double. Fertility TFR (total fertility rate)-the average number or children a woman will have throughout her childbearing years. The world’s rate is 2.6. Mortality IMR (Infant Mortality Rate): the annual number of deaths under 1 year of age compared with total live births (per 1,000) LE (Life Expectancy) measures the average number of years a newborn infant can expect to live at current mortality levels. Demographic Transition: Stage 1 LOW GROWTH: – pre-Industrial society – Birth and death rates high and fluctuated based on natural events, disease and drought. – Population burst in 8000BC was because of the AGRICULTURAL REVOLUTION, when human first domesticated plants and animals. Stage 2 HIGH GROWTH: – After 1750 the world’s population suddenly began to grow 10x’s faster. – This is a result of the INDUSTRIAL REVOLUTION. – Helped improve agriculture, sanitation, and personal hygiene. – Did not diffuse to many countries in Africa, Asia, and Latin America. Stage 2 (con’t) Late 20th century “push” into this stage was caused by the MEDICAL REVOLUTION. – Medical technology diffused to LDC’s in Africa, Asia, and Latin America. Stage 3 MODERATE GROWTH: – CBR begins to drop sharply because of changes in social customs-fewer children, economic changes-more people are living in urban areas – CDR continues to fall but slowly Stage 4 LOW GROWTH: – CBR=CDR – NIR is approaching ZERO which is called ZERO POPULATION GROWTH (ZPG) – This is a TFR of approximately 2.1. – Causes: social customs, women in the labor force, increased leisure time, increase in income, Population pyramids Age cohorts Age distribution Dependency ratio Sex ratio World Population Growth: Large-scale population growth in the United States will be a result of immigration from countries in Latin America and Asia still in stage 2 or 3. Countries in stage 2 of the demographic transition are encouraged to move to stage 3 rapidly to discourage rapid population growth. Malthus: Explanations Neo-Malthusians Critics Theory vs. Reality Declining Birth Rates: Why? – Education of women regarding reproductive rights, etc. – Effective contraceptive use – Improved health-care programs – Immunization programs Epidemiological Transition: What is it? Focuses on distinctive causes of death in each stage of the demographic transition. Stages 1, 2 Stages 3, 4 Stage 5 Stage of re-emergence of infectious diseases and parasites.