What was the most significant difference between agriculture as it developed in Eurasia and the Americas?

By the end of Unit 8, students should be able to:
1. Analyze what propelled the expansion and interconnection of agrarian civilizations.
2. Investigate the implications of interconnected societies and regions by looking at how

commerce has spread.

8.0 ExpansionIn 1400, the world was divided into four world zones. The expansion, exploration, and the desire toexpand trade led these world zones to be connected. The resulting connections dramaticallyincreased the opportunities for collective learning.

8.1 Exploration and Interconnection

8.2 Commerce and Collective Learning

WHY DID CIVILIZATIONS
EXPAND?Agrarian civilizations needed to expand because they made their wealth mainly fromresources they grew from the land.A piece of land was only able to produce a limited number of crops each year, andenvironmental changes affected the quality and size of the crops.The only certain way to increase productivity was to take over more land.However, innovations designed to improve the effectiveness of armies were also used toimprove economic productivity. Iron developed for weapons could be used to make better plows, which improved farm

productivity. 

Similarly, roads built to allow armies to move from region to region also allowed merchants to
trade over wider areas, thus making for more productive economies.

Ancient Rome

THE FOUR
WORLD ZONESIn the era of agrarian civilizations, the world was divided into four major zones: Afro-Eurasia, the Americas, the Australasian, and the Pacific.Afro-Eurasia was the dominant zone because it was the first to develop agriculture, was the largest zone in terms of area, had the largest population, the most resources, and the largest network for collective learning.

People settled the three other zones much later in this age. While farming was critical to life in the Americas, foraging was still the dominant lifestyle for much of this age in the Australasian and Pacific zones.

HOW DID THE WORLD
BECOME INTERCONNECTED?In the age of agrarian civilizations the world was divided into four zones: Afro-Eurasian, Americas, Australasian, and Pacific.Some innovations increased the possibility for collective learning within agrarian civilizations.Writing, paper, and printing revolutionized the storage of information, leading to a huge increasein collective learning.Some innovations increased the possibility for collective learning among agrarian civilizations.Advances in transportation, communication, and road systems also helped to increaseconnections and increase collective learning.Growth resulted from innovations, but it was hard to sustain. Population growth tended tooutpace innovation during this time, and starvation, disease, and famine often arose, bringing

this growth to a halt.

The building of roads helped connect different communities which helped speed up collective learning.

THE FIRST SILK ROADSExchange networks not only facilitated the movement of goods, but they also stimulated innovation because they helped spread collective learning further and create more diverse networks.Agrarian civilizations were critical to the operation of the Silk Road because they created stability and security, built and maintained road networks, and innovated to support traders.Important trade goods moved in both directions along the Silk Road. The Romans imported Chinese silk, Han iron, Arabian and Indian spices, and agricultural products. The Chinese imported agricultural products, art, glassware, and horses from Central Asia, India, and the Mediterranean.Innovations like the use of the Bactrian camel and the discovery and use of the trade winds across the Indian Ocean were critical to the success and expansion of the Silk Roads.

Trade on the Silk Road stimulated economic growth, which benefited the agrarian civilizations involved. The Silk Road also made the Afro-Eurasian zone more connected and its networks more diverse than those of the other world zones. These benefits, coupled with the many advantages that Afro-Eurasia already enjoyed over other world zones, allowed it to dominate the others after 1492 when the world became interconnected.