Alfred Crosby named the Columbian exchange only in 1972
After 1492, plants, animals and microbes surged between the Americas and Afro-Eurasia in what is called the Columbian exchange. Historian Alfred W. Crosby coined the phrase in a 1972 book, and it spread fast. The potato alone may explain a fifth of the Old World's later population growth.
Free and enslaved Old World migrants remade New World populations as Indigenous numbers fell. Staples such as maize, the potato, the tomato, tobacco, cassava, sweet potato, and chili crossed eastward and lifted Old World food supply. Rice, wheat, sugar cane and livestock moved west. So did Old World diseases, which cut Indigenous American populations by 80 to 95 percent and all but wiped them out in the Caribbean. In the first three centuries after Columbus, far more Africans were shipped to the Americas than Europeans chose to go.
Crosby, at the University of Texas at Austin, mapped biological and cultural transfers; his later Ecological Imperialism (1986) extended the thesis. Consensus holds humans entered the Americas from Siberia millennia earlier; speculative pre-Columbian contacts abound, with possible Polynesian–South American links around 1200 including sweet potato adoption.
Earlier encounters left little trace. The Norse who stayed briefly in Greenland, Newfoundland and Vinland around the eleventh century changed nothing measurable in the Americas, though sheep's sorrel turned up in Greenland then. Potatoes, confined to South America before 1500, were widespread in Europe by the 1700s and important in India and North America; estimates credit them with 12 to 25 percent of Afro-Eurasian population growth between 1700 and 1900 and 47 percent of that era's rise in urbanisation. Cassava, carried from South America by the Portuguese in the sixteenth century, gradually displaced sorghum and millet as Africa's leading food crop.
Source: Columbian exchange
