Name: _____________________________________ Period: ___________ Populations: Human Population Growth Historical Overview Like the populations of many other living organisms, _____________________ ___________________________________________________. For most of human existence, __________________________________________. ________________________________ kept population sizes low. About _______________________, the human population began growing more rapidly. Life was made easier and safer by advances in _________________________. Death rates were dramatically reduced due to _________________________ _______________________________________________________________________. With these advances, the human population experienced exponential growth. Human Population Growth Patterns of Population Growth The scientific study of human populations is called ______________________. Prentice Hall Demography examinesCopyright thePearson characteristics of human populations and attempts to ___________________________________________________________. _______________________________________________________________________ help predict why some countries have high growth rates while other countries grow more slowly. The Demographic Transition Over the past century, population growth in the United States, Japan, and much of Europe has __________________________. According to demographers, these countries have completed the_______________________________, a dramatic change in birth and death rates. The demographic transition has _______________________. o In stage 1, ______________________________________________________. o In stage 2, ______________________________________________________. _______________________________________. o In stage 3, _______________________________________________________ _______________________. Patterns of Population Growth The demographic transition is complete when the birthrate falls to meet the death rate, and population Age Structure growth stops. Population growth depends, in part, ________________________________ _________________________________________. Copyright Pearson Prentice Hall Demographers can predict future growth using models called _________ _____________________. Age-structure diagrams show the population of a country broken down by ________________________________________. U.S. Population In the United States, there are nearly equal numbers of people in each age group. This age structure diagram predicts a slow but steady growth rate for the 80+ 60–64 Age (years) 40–44 20–24 0–4 Rwandan Population In Rwanda, there are many more young children than teenagers, and many more teenagers than adults. 80+ Males Females 60–64 Age (years) 40–44 20–24 This age structure diagram predicts a 0–4 population that will Future Population Growth Percentage of Population double in about 30 years. To predict human population growth, demographers must consider the Copyright Pearson Prentice Hall _______________________________________________________________________ double in about 30 ______________________________________. years. If growing countries move toward the demographic transition, ___________ ___________________________________. Ecologists suggest that if growth does not slow down, there could be ___________________________________________________________________. Economists assert that ______________________________________________ may control the Copyright Pearson Prentice Hall growth. negative impact of population Survivorship A survivorship curve is a graph showing _______________________________ _________________________________________________ (e.g. males/females). Survivorship curves can be constructed for a given ______________(a group of individuals of roughly the same age) based on a life table Survivorship curves tell us something about ______________________________ ___________________. There are basically three types of survivorship curves: Type I survivorship curves are for species that have a high survival rate of the young, live out most of their expected life span and die in old age. Examples: _____________________ Type II survivorship curves are for species that have a __________________________ ______________________________________________. Death could be due to hunting or diseases. Examples : coral, squirrels, honey bees, birds, and many reptiles. Type III survivorship curves are found in species that ___________________________ ______________________________________________. Examples: Plants, oysters and sea urchins