The exchange of crops, animals, and diseases between Europe and America (and Africa).
1. Diseases brought by Europeans, especially smallpox, will wipe out ~90% of the native population
2. Crops transplanted to America will be bad for native plants, and European grazing animals will be bad for native plants
3. American crops brought to Europe (maize, tomatoes, potatoes, tobacco) will lead to a increased food production and a massive population boost in Europe that will spill into America.
- The exchange becomes a cycle. The increased population in Europe required more centralized governments. The new governments were for/able to explore more because they had more power. As a result, more Europeans in America.
- Europeans in America > American food in Europe, European diseases in America > Population boom in Europe > More Europeans in America