This was at a farm about 300 miles northwest of Shanghai. Sweet potatoes are often eaten raw in rural China–a curiosity to Westerners like me. I didn’t realize that I had been staring until the boy ran to seek the protection of his father, who was hoeing a row of sweet potatoes. The father glared at me as I waved an apology. Because I don’t speak Chinese, I couldn’t tell him that I had been staring not at his son, but at the sweet potato in his hand. Nor could I say that I was staring because the sweet potato was an emblem of four hundred years of convulsive global change.
Sweet potatoes are native to Central America. Spanish ships carried them to Manila in the 1570s, and then a Chinese ship captain smuggled the vines past Spanish customs by wrapping them around ropes and coiling the ropes in a basket. He took the contraband plants to Fujian, in southeast China, across from Taiwan. It was a time of famine in China. The captain’s son took the sweet potatoes to the governor of Fujian, who in turn ordered farmers to plant the fanshu (foreign tubers). The famine ended. Other regions took up sweet potatoes to solve their food problems. Millions of lives were saved. For three centuries the food of the Chinese poor was not rice but sweet potato.
How did that Chinese kid get his sweet potato? Christopher Columbus. Scientists view Columbus as the man who inadvertently began an explosive global biological swap. After he established contact between the eastern and western hemisphere, thousands of plant and animal species ricocheted around the continents. It was the biggest event in the history of life since the death of the dinosaurs. The Colombian Exchange, as historians call it, is why there are tomatoes in Italy, oranges in the United States, potatoes in Ireland, chili peppers in Thailand–and sweet potatoes in China.
Expanding on the work of Alfred Crosby, Charles Mann’s exposition on the environmental and social effects of the “Colombian Exchange” gives a solid background to the burgeoning globalism that took place at the time and that forms a sub-structure of our present situation. Dense, many dates, and facts, but his flowing narrative style easily carries the sedimentary load of historical information. The book explores the effects of the massive interchange of resources, biota, and humans that was precipitated by the ‘discovery’ of the Americas. Covering items such as the arrival of the potato in both Europe and China, and the wide and powerful sweep of slavery, it supports the argument of the energy availability within social systems is a necessary condition for the system to thrive. And when those energy sources collapse for one reason or another, the social system fails.