Today we have specialized farms for certain animals, crops, and other products, as well as the individual family farms. Talk with the class about how medicine has improved throughout time. Give examples of early treatments for disease such as leaching and bleeding. Tell how these treatments actually weakened the patient. The discovery of a polio vaccination by Jonas Salk and vaccinations for other diseases should be briefly explained.
Mosquitoes carry many diseases.
Malaria is one of these. The discovery of this led to fewer malaria outbreaks. By settling in areas with fewer mosquitoes, and controlling the population of mosquitoes, many diseases can be controlled. Ask the students why all of these advancements in medicine have increased the population growth rate. Talk with the students about sanitation.