ANTH 3612 Population and Society, Spring 2012 2.1 Population ...
ANTH 3612 Population and Society, Spring 2012 2.1 Population Growth Key Terms Paleolithic: Old Stone Age From use of stone tools to food production. Neolithic: New Stone Age Began with food production ≈ 8000 BC. Foragers: Hunter-gatherer subsistence. Agriculturalists: Farmers, sedentary food producers. Why did the human population begin to grow much faster during the Neolithic period? Because people lived longer and fewer died? i.e., Decreasing mortality resulting from nutritional improvements and a more reliable food supply? Because more people were born? i.e., Increasing fertility resulting from the shift to a sedentary lifestyle?
Foragers: Regulating Fertility, Physiological Factors Seasonal nutritional stress and high levels of physical activity Results = late onset of menarche, irregular ovulation, spontaneous abortions Foragers: Regulating Fertility, Social, Economic, & Cultural Factors Late formation of marital unions High mobility (must carry infants) Prolonged breastfeeding (lactational amenorrhea) Induced abortions and infanticide Result = relatively low fertility and low number of kids reared
Agriculturalists Sedentary lifestyle = earlier menarche. Less mobility = easier to care for children. Agriculture = more reliable nutrition, less seasonal nutritional stress, more regular ovulation. Europe’s Black Death Black Death: 1348-1349 Killed 30% - 50% of Europe’s Population Levels of mortality similar in cities and rural areas, and among nobility and peasants. Combination of diseases: bubonic plague and anthrax. Doubling Time: The number of years it takes for a population to double in size. Doubling time = 70 / % annual growth rate The Demographic Transition From high fertility and high mortality to low fertility and low mortality Transitional Phase: High Population Growth Demographic Transition = A Set of Transitions Epidemiological Transition (sanitation, medical advances, decrease in infant mortality) Fertility Transition (from “natural” to “controlled” fertility) Migration Transition (high rate of population growth, rural to urban and international migration) Age Transition (changing age distribution – more elderly)
Difference Earliest demographic transitions (e.g., Europe) transpired over long time. Population growth rates were never very high. Later transitions (e.g., the rest of the world) transpiring over shorter intervals. Population growth rates generally very high.
What We Know (Karen Mason) Mortality decline is usually a necessary, but not sufficient, condition for fertility decline. The conditions under which transitions occur vary. If families exceed their ability to support children, parents will resort to some form of fertility control. Factors that influence transitions (e.g., contraceptive knowledge) can diffuse from one place to another. Fertility control depends on availability and acceptable forms of such control (e.g., abortion, infanticide, contraception). The Good News Is . . . Fertility rates are dropping worldwide (with some exceptions). Rates of population growth are dropping worldwide (with some exceptions). The Bad News Is . . . The number of people added each year is huge. Population Momentum (Blue and Espenshade) The phenomenon occurs because a history of high fertility has resulted in a high proportion of women in the reproductive ages, and these ensure high crude birth rates long after the age-specific rates have dropped” (Keyfitz 1971: 71). Purpose: document highly regular pattern of population momentum across demographic transitions. New Insight Demographic transition affects age-sex structure of population (we know that). Resulting age distributions affect ongoing demographic transition.
What Does This Analysis Tell Us? Despite falling birth rates (stages 3-4 of demographic transition) populations will continue to rise due to population momentum. Peak momentum Stage 4 Countries: 1980 (Brazil, Indonesia) Stage 3 Countries: 1995 (Egypt, India) Stage 2 Countries: 2015 (Kenya, Nigeria) Stage 5 Countries (Japan, Sweden) are, or will begin to, experience population declines.
Foragers: Regulating Fertility, Physiological Factors Seasonal nutritional stress and high levels of physical activity Results = late onset of menarche, irregular ovulation, spontaneous abortions Foragers: Regulating Fertility, Social, Economic, & Cultural Factors Late formation of marital unions High mobility (must carry infants) Prolonged breastfeeding (lactational amenorrhea) Induced abortions and infanticide Result = relatively low fertility and low number of kids reared
Agriculturalists Sedentary lifestyle = earlier menarche. Less mobility = easier to care for children. Agriculture = more reliable nutrition, less seasonal nutritional stress, more regular ovulation. Europe’s Black Death Black Death: 1348-1349 Killed 30% - 50% of Europe’s Population Levels of mortality similar in cities and rural areas, and among nobility and peasants. Combination of diseases: bubonic plague and anthrax. Doubling Time: The number of years it takes for a population to double in size. Doubling time = 70 / % annual growth rate The Demographic Transition From high fertility and high mortality to low fertility and low mortality Transitional Phase: High Population Growth Demographic Transition = A Set of Transitions Epidemiological Transition (sanitation, medical advances, decrease in infant mortality) Fertility Transition (from “natural” to “controlled” fertility) Migration Transition (high rate of population growth, rural to urban and international migration) Age Transition (changing age distribution – more elderly)
Difference Earliest demographic transitions (e.g., Europe) transpired over long time. Population growth rates were never very high. Later transitions (e.g., the rest of the world) transpiring over shorter intervals. Population growth rates generally very high.
What We Know (Karen Mason) Mortality decline is usually a necessary, but not sufficient, condition for fertility decline. The conditions under which transitions occur vary. If families exceed their ability to support children, parents will resort to some form of fertility control. Factors that influence transitions (e.g., contraceptive knowledge) can diffuse from one place to another. Fertility control depends on availability and acceptable forms of such control (e.g., abortion, infanticide, contraception). The Good News Is . . . Fertility rates are dropping worldwide (with some exceptions). Rates of population growth are dropping worldwide (with some exceptions). The Bad News Is . . . The number of people added each year is huge. Population Momentum (Blue and Espenshade) The phenomenon occurs because a history of high fertility has resulted in a high proportion of women in the reproductive ages, and these ensure high crude birth rates long after the age-specific rates have dropped” (Keyfitz 1971: 71). Purpose: document highly regular pattern of population momentum across demographic transitions. New Insight Demographic transition affects age-sex structure of population (we know that). Resulting age distributions affect ongoing demographic transition.
What Does This Analysis Tell Us? Despite falling birth rates (stages 3-4 of demographic transition) populations will continue to rise due to population momentum. Peak momentum Stage 4 Countries: 1980 (Brazil, Indonesia) Stage 3 Countries: 1995 (Egypt, India) Stage 2 Countries: 2015 (Kenya, Nigeria) Stage 5 Countries (Japan, Sweden) are, or will begin to, experience population declines.
