If you're seeing this message, it means we're having trouble loading external resources for Khan Academy.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

8. Expansion & Interconnection
Early humans had pretty small social networks. At most, they probably met only a couple hundred people who probably all lived very similar lives to their own. As people started farming, these networks got larger. People were increasingly specialized in their work and trade. Populations in cities got larger. Trade reached across longer distances, bringing together people with very different lives and ways of thinking.
All content in “8. Expansion & Interconnection”

8.1 How did the world become interconnected?

Crossing dangerous deserts and deep ocean waters to connect the four world zones wasn't easy. After 1400, innovation and collective learning took a giant leap forward.

8.2 Why was commerce so important?

As systems of exchange and trade made the world a smaller place, the Afro-Eurasian world zone gained power.

8.3 Ways of knowing: Expansion and interconnection

Travelers and explorers came back from the corners of the earth with fantastic stories and new ideas and technologies. Their adventures, and they were true adventures, offer insight into the newly connected world.

Practice and feedback

Test your knowledge and skills! Investigate how and why our reaction and response to disease has changed, and then take on the quiz and glossary challenge.