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APES Friday, December 6, 2013 Reminders: Mid-Term FRQ is Thursday, Dec. 12 th Mid-Term Multiple Choice is Tuesday, Dec. 17 th Today’s Schedule: Begin Unit 7 Notes Go Over Unit 6 Test
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Human Population Ecology Chapter 10
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Population Ecology Demography Study of the size, composition, and distribution of human populations and the causes and effects of their changes Population change = (Birth + Immigration) – (Death + Emigration) Instead of using total #s of birth & deaths, demographers use birth rate (crude birth rate) and death rate (crude death rate)
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Population Ecology Crude Birth/Death Rate = The number of births/ deaths per 1000 individuals per year Developed countries have a closer crude birth & death rates Developing countries have higher crude birth rates than death rates
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Reasons for human population increase: Movement into new habitats and climate zones Early and modern agriculture methods Control of infectious diseases through: Sanitation systems Antibiotics Vaccines Most population growth occurred over last 100 years due to drop in death rates Population Ecology
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Human Population Size
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Population Ecology Human Population Size Exponential pop growth has slowed Decreased from 2.2% in 1963 to 1.25% in 2004 Sounds good, but population has doubled to 7 billion Pop growth rate in developed countries: 0.1% Pop growth rate in developing countries: 1.5% Top growing countries: India, China, Pakistan, Nigeria, Bangladesh, & Indonesia
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APES Monday, December 9, 2013 Reminders: Mid-Term FRQ is THIS Thursday, Dec. 12 th Mid-Term Multiple Choice is Tuesday, Dec. 17 th Mid-Term Study Guide in ONLINE – will get tomorrow! Unit 7 Vocab due Friday, 12/13 Today’s Schedule: Cont. Unit 7 Notes
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Population Ecology Human Population Size One measure is Doubling Time The time it takes for a population growing at a specific rate to double its size Rule of 70: quick way to calculate doubling time 70_________ = doubling time percentage growth rate Example: Growth rate in 2004 was 1.5%. If that rate continues, how many years will it take for the population to double? Answer: 70/1.5 = ~47 years
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Population Ecology Fertility Rates Fertility: number of births that occur to an individual woman or a population Two types of fertility rates affect a country’s pop size and growth rate: 1. Replacement level fertility: number of children a couple must bear to replace themselves. Typically a bit higher than 2 due to some females dying before reproductive age. (developed countries = 2.1, developing as high as 2.5 children) 2. Total Fertility rate (TFR): Average number of children a woman typically has. Global TFR = 2.8 kids, Developed = 1.6, Developing = 3.1
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Population Ecology Total Fertility Rates
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Population Ecology United States: Currently 300 million people Birth Rates Now near replacement level Most recent peak was the WW II Baby Boom
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Population Ecology U.S. Growth Rate Still growing faster than any other developed country One reason: IMMIGRATION!
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Population Ecology Factors Related to Lowering Birth Rates: The later (or older) the children enter the work force The higher the cost of raising and educating children Availability of retirement/pension systems - kids don’t have to support elderly parents Families living in urban areas – don’t need kids to work farms Higher education and employment rates of women Lower infant mortality rate Higher age at marriage (fewer kids when marry at 25+) Availability of legal abortions Availability of reliable birth control methods Religious and cultural beliefs
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Population Ecology Lowering Death Rates: Improvements in health care, nutrition, sanitation, water supplies lead to a higher life expectancy & lower infant mortality Life expectancy = average # of years a newborn infant can expect to live Infant mortality rate = # babies out of every 1,000 born who die before 1 year old Global life expectancy ~ 67 years Developed country life expectancy = 77 years Developing country life expectancy = 65 years (Africa = 49 years *AIDS)
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Population Ecology Infant Mortality: Good indicator of society’s quality of life High infant mortality suggests insufficient &/or poor food, and high disease Developed country infant mortality ~ 7 Developing country infant mortality ~ 61 U.S. infant mortality relatively high among developed countries b/c: Inadequate health care Drug addiction Teen pregnancies
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Population Ecology Population Growth due to Immigration: Only 3 countries encourage immigration: Canada Australia United States Immigration accounts for ~41% of U.S.’s annual pop growth Mostly from Latin America and Asia Debate of immigration???
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Population Ecology Age Structure = the distribution of males and females in each age group Three groupings: Pre reproductive: 0-14 years Reproductive: 15-44 years Post reproductive: 45+
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Population Ecology Age Structure Diagram Shape indicates population growth trend Large base means many pre reproductive individuals pop growth
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Population Ecology Age Structure (U.S. Baby Boom) By ~ 2030, 1 of every 5 people will be 65+
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Population Ecology Effects of Population Decline ~40 countries have stabilized or declining pops higher proportions of older people Effects : Higher medical care costs Depleted social security Fewer tax payers Affects immigration (need workers) ARTICLE to READ! Japan, Russia, Germany, Bulgaria, Hungary, Ukraine, Serbia, Greece, Portugal, & Italy
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Population Ecology How can we slow human population growth? Three most important steps: 1. Reduce poverty through economic development & education 2. Elevate the status of women 3. Encourage family planning & reproductive health care Step1: Promoting economic development leads to demographic transition: As countries become industrialized & economically developed, first their death rates decline, then their birth rates decline
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Population Ecology Demographic Transition Model
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Population Ecology Demographic Transition Model Stage 1 - Preindustrial: Pop growth very slow b/c of high birth & death rate Stage 2 - Transitional: pop grows rapidly b/c birth rates are high & death rates drop b/c of better food & health Stage 3 – Industrial: Pop growth slows b/c birth & death rates drop Stage 4 – Postindustrial: pop growth stabilizes or declines Developed countries in Stage 3 or 4 Developing countries either in Stage 2 or some in Stage 1 (Africa dealing with AIDS)
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Population Ecology Step 2: Empowering Women Women who can get (have the right to) education & work have less children Example: poor, illiterate women have 5-7 children compared to literate who have <2 Depends a lot on cultural & religious beliefs in role of women (Rural Africa)
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Population Ecology Step 3: Family Planning Provides educational and clinical services that help couples choose how many children to have & when Includes birth spacing, birth control, health care for pregnant women & infants Family planning is responsible for a drop of at least 55% in TFRs in developing countries (from 6 in 1960 to 2.7 in 2010) Example: Thailand cut pop growth rate from 3.2% in 1971 to 0.6% in 2010 (Rural Africa)
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Population Ecology Step 3: Family Planning Still have problems: ~40% of all pregnancies in developing countries are unplanned & 26% end in abortion (US had ~1.3 mil abortions in 2007) Solutions: expand family planning to include teenagers & unmarried women educating men birth control for men? (Rural Africa)
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Population Ecology China World’s most populous country – 1.3 billion people 1960s – serious threat of mass starvation due to pop growth Established one-child per family policy Gov provides contraceptives, sterilizations, and abortions for married couples Married couples pledge to have 1 kid – get better housing, more food, free health care, etc. TFR in 1972 was 5.7, in 2010 was 1.5 India World’s 2 nd largest pop; projected to be largest in 2015 Began world’s first family planning in 1952 but only moderately successful TFR is ~ 2.6 b/c (1) couples believe need children to care for them in old age, (2) cultural preference for males
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Population Ecology Overall idea: human pop is still growing globally Some countries still growing too fast environmental problems Some countries have declining pop growth economic problems Is there an answer?? Cultural carrying capacity The number of people that could live on the planet in reasonable comfort and freedom without impairing the ability of the planet to sustain future generations Assignment Read “Moral Implications of Cultural Carrying Capacity” by Garrett Hardin
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