Guns, Germs, and Steel Lesson Plan

Read the following excerpts from Chapter 11 on epidemics:

The rapid spread of microbes, and the rapid course of symptoms, mean that everybody in a local human population is quickly infected and soon thereafter is either dead or else recovered and immune. No one is left alive who could still be infected. But since the microbe can't survive except in the bodies of living people, the disease dies out, until a new crop of babies reaches the susceptible age--and until an infectious person arrives from the outside to start a new epidemic.

Only in larger populations can the disease shift from one local area to another, thereby persisting until enough babies have been born in the originally...