1. Early humans originated in Eastern Africa around 200,000 years ago and the population was nearly wiped out around 75,000 years ago. Agriculture emerged around 8,000 years ago which led to permanent settlements and social hierarchies. 
2. Mesopotamia and Ancient Egypt were early civilizations that developed agrarian lifestyles around 8,000 years ago which allowed for specialization, larger settlements, and complex social structures. 
3. Ancient Rome expanded from 500 BC to 500 AD, influencing modern governments, customs and languages. The Romans were renowned engineers who built extensive road networks, aqueducts and structures like the Colosseum and Pantheon.