1. Chapter 5 Section 3 Biology 9 Mr. Guillen Period 5/6

2. Key Questions How has the size of the human population changed over time? Why do population growth rates differ among countries?

3. Exponential Human Population Growth As life became easier, human population began to grow Industrial Revolution (import/export in 1800’s) Food supplies became more reliable Healthcare improved Sanitation and Nutrition Result?? Exponential Growth

4. World Population Growth Slows Human population growth rate was highest b/w 1962-1963 Population is still growing rapidly, but the growth rate is slowing. B/w 1804 and 1927, 1 billion  2 billion in population. B/w 1927 and 1960 it grew to 3 billion. Growth rate increased until 1999 and then it began to slow. Why??

5. Patterns of Human Population Growth Scientific study of human population and its’ growth is demography. In demography scientists study birth rate, death rate, and age structure. For many years, human societies had high birth rates and death rates. Then, death rates dropped and birth rates remained high. Over the past century, birthrates in U.S., Japan, and Europe also fell. As a result, growth rate slowed. This is known as a demographic transition because the population change went from high B.R. and D.R.  low B.R. and D.R. 3 stages: High and High  High B.R. and low D.R.  Low and Low

6. Age Structure and Population Growth Age structure predicts how quickly a population will grow. Example: Guatemala There are more children than teenagers and more teenagers than adults. Result: over the next 30 years the population will double in Guatemala.

7. Future Population Growth Scientists also study how diseases affect affect death rates. Currently AIDS is causing very high death rates in Africa and parts of Asia. World population will grow to 9 billion people by 2050. It is expected that the population will grow more slowly over the next 50 years than the past 50 years. Why??

8. In Class Assignment 3 paragraphs. 6-8 sentences per Why is the population expected to grow more slowly over the next 50 years than the past 50 years? Due at the end of the period. NO you can’t work in groups, NO you can’t talk, NO you can’t go to the bathroom, NO you can’t be on your phones. “It’s your lunch, not mine.” –Mr. Guillen