Living close to animals exposed humans to new diseases—smallpox, flu, measles, chicken pox, malaria, tuberculosis, rabies—while living in larger communities generated epidemics for the first time in human history. Furthermore, relying on a small number of plants or animals [made] early agricultural societies vulnerable to famine, in case of crop failure, drought, or other catastrophes. The [introduction] of agriculture bore costs as well as bene Cause and effect.