Human Population Growth
Brain Pop MovieAnd
Quiz!
Human Population TrendsHistorical Perspective
Limiting Factors Scarce Food Incurable Diseases
Only ½ the Children in the World Survived to Adulthood
Therefore families had many children to ensure some would survive.
History of Human Population Trends
Source: Glencoe, Biology, 2009
History of Human Population Trends cont’d
Source: Glencoe, Biology, 2009
Human Population Trends Human population
tends to increase with time.
500 years ago a shift to rapid growth.
Agriculture and Industry Reliable Food Supply Shipping Improved Sanitation Healthcare
All decreasing the death rate and increasing life expectancy.
Source: Glencoe, Biology, 2009.
Increase in Human Population Growth Over Time
(Prentice Hall, Biology, 2003)
Source: Glencoe, Biology, 2009.
Patterns of Population Growth Demography
Scientific study of human population growth.
What factors do scientists need to take into consideration to predict population growth? Birthrates Death Rates Age Structure
Demographic Transition
Dramatic change in birth and death rates
As countries become developed there is a shift in birth rate and death rate
What is happening in the graph?
Demographic Transition Cont. Transition is complete when the
birthrate falls to meet the death rate. Zero Population Growth
What countries have undergone demographic transition? US Europe Japan
Population Growth Rates of Countries
Source: Glencoe, Biology, 2009.
Predicting Population Growth
Age-structure diagrams Graphs numbers of people in different
age groups in the population
How could this help Biologists predict population growth?
Interpreting Age-Structure Diagrams
Pre-Reproductive, Reproductive, and Post-Reproductive Classifications
Source: Glencoe, Biology, 2009.
Developed Vs. Underdeveloped Country
What are the characteristics of each country? Developed
Underdeveloped
Human Carrying Capacity Estimated to be around 8-
10 billion people
Threat of disease and starvation once reached
Technology has temporarily increased human carrying capacity
FOOD FOR THOUGHT ACTIVITY
Source: Glencoe, Biology, 2009
Graphic Sources http://www.coremedicalgroup.com/pix/
scrubs_lg.jpg http://nue.okstate.edu/Rockefeller/obregon.jpg http://www.eatonco.org/_derived/2L-
sanitation.htm_cmp_sanitation010_bnr.gif http://www.geography.learnontheinternet.co.uk/
images/popn/demographictransition.gif http://www.census.gov/cgi-bin/ipc/idbsum.pl?
cty=CF http://www.census.gov/cgi-bin/ipc/idbsum.pl?
cty=US