The Columbian Exchange, also known as the Grand Exchange, was a dramatically widespread exchange of animals, plants, culture, human populations (including slaves), communicable disease, and ideas between the American and Afro-Eurasian hemispheres following the voyage to the Americas by Christopher Columbus in 1492.:163 The term was coined in 1972 by Alfred W. Crosby, a historian at the University of Texas at Austin, in his eponymous work of environmental history.:27 The contact between the two areas circulated a wide variety of new crops and livestock which supported increases in population in both hemispheres. Explorers returned to Europe with maize, potatoes, and tomatoes, which became very important crops in Europe by the 18th century. Similarly, Europeans introduced manioc and peanut to tropical Asia and West Africa, where they flourished and supported growth in populations on soils that otherwise would not produce large yields.
In the biological and ecological exchange that took place following Spanish establishment of colonies in New World, people of Europe and Africa settled in the New World, and animals, plants and diseases of Eurasia and the Western Hemisphere were introduced to each area in the interchange. Many slaves were also exchanged
This exchange of plants and animals transformed European, American, African, and Asian ways of life. New foods became staples of human diets, and new growing regions opened up for crops. For example, before AD 1000, potatoes were not grown outside of South America. By the 1840s, Ireland was so dependent on the potato that a diseased crop led to the devastating Irish Potato Famine. Since being introduced by 16th-century Portuguese traders, who brought them from the Americas, maize and manioc replaced traditional African crops as the continent's most important staple food crops. 16th century Spanish colonizers introduced new staple crops to Asia from the Americas, including maize and sweet potatoes, contributed to the population growth in Asia. European exploration of tropical areas was aided by the New World discovery of quinine, the first effective treatment for malaria.:164
One of the first European exports, the horse, changed the lives of many Native American tribes on the Great Plains, allowing them to shift to a nomadic lifestyle based on hunting bison on horseback. Tomato sauce, made from New World tomatoes, became an Italian trademark and tomatoes were widely used in France, while coffee from Africa and sugar cane from Asia became the main commodity crops of extensive Latin American plantations. Introduced to India by the Portuguese, chili/paprika from South America is today an integral part of Indian cuisine, as are potatoes.
Before regular communication had been established between the two hemispheres, the varieties of domesticated animals and infectious diseases that jumped to humans, such as smallpox, were strikingly larger in the Old World than in the New. Many had migrated west with animals or people, or were brought by traders from Asia, so diseases of two continents were suffered by all. While Europeans and Asians were affected by the Eurasian diseases, their endemic status in those continents over centuries caused many people to acquire immunity. By contrast, "Old World" diseases had a devastating impact on Native American populations because they had no natural immunity to the new diseases. The smallpox epidemics are believed to have resulted in the largest death tolls among Native Americans, surpassing any wars and far exceeding the mortality from the Black Death.:164 It is estimated that upwards of 80–95 percent of the Native American population died in these epidemics within the first 100–150 years following 1492; the most affected regions in the Americas lost 100% of their population.:165
Before the Columbian Exchange, there were no oranges in Florida, no bananas in Ecuador, no paprika in Hungary, no tomatoes in Italy, no potatoes in Ireland, no coffee in Colombia, no pineapples in Hawaii, no rubber trees in Africa, no cattle in Texas, no donkeys in Mexico, no chili peppers in Thailand or India, and no chocolate in Switzerland.
Tomatoes in the Old World 
It took three centuries after their introduction in Europe for tomatoes to become readily accepted. In fact, of all the New World plants in Italy, only the potato took as long as the tomato to gain acceptance. In large part this was due to sixteenth-century physicians believing that this native Mexican fruit was poisonous and the generator of "melancholic humors." In 1544, Pietro Andrea Mattioli, a Tuscan physician and botanist, suggested that tomatoes might be edible, but no record exists of anyone consuming them at this time. On October 31, 1548 the tomato was given its first name anywhere in Europe when a house steward of Cosimo de' Medici, the grand duke of Tuscany, wrote to the Medici private secretary that the basket of pomi d'oro "had arrived safely." At this time the label pomi d'oro was also used to refer to figs, melons, and citrus fruits in treatises by scientists.
Tomatoes were grown mainly as ornamentals early on after their arrival in Italy. For example, the Florentine aristocrat Giovanvettorio Soderini wrote how they "were to be sought only for their beauty" and were grown only in gardens or flower beds. In fact, tomatoes were grown in elite town and country gardens in the fifty years or so following their arrival in Europe and were only occasionally depicted in works of art. However, in 1592 the head gardener at the botanical garden of Aranjuez near Madrid, under the patronage of Philip II of Spain wrote that "it is said [tomatoes] are good for sauces." Besides this account, tomatoes remained exotic plants grown for ornamental purposes, but rarely for culinary use. The combination of pasta with tomato sauce only dates back to the late nineteenth century. There are around 32,000 acres (12,950 ha) of tomatoes cultivated in Italy today and there are still areas where relatively few tomatoes are grown and consumed.
Unintentional introductions 
Plants that arrived by land, sea, or air in "ancient" times (or before 1492 in the U.K.) are called archaeophytes, and plants introduced to Europe after those times are called neophytes. In addition to the diseases mentioned above, many species of organisms were introduced to new habitats on the other side of the world accidentally or incidentally. These include such animals as brown rats, earthworms (apparently absent from parts of the pre-Columbian New World), and zebra mussels, which arrived on ships.
Invasive species of plants and pathogens also were introduced by chance, including such weeds as tumbleweeds (Salsola spp.) and wild oats (Avena fatua). Some plants introduced intentionally, such as the kudzu vine introduced in 1894 from Japan to the United States to help control soil erosion, have since been found to be invasive pests in the new environment. Fungi have been transported, such as the one responsible for Dutch elm disease, killing American elms in North American forests and cities, where many had been planted as street trees. Some of the invasive species have become serious ecosystem and economic problems after establishing in the New World environments.
Introduced feral populations 
Escaped and feral populations of non-indigenous animals have thrived in both the Old and New Worlds, often displacing native species.
Gray squirrels have been particularly successful in colonising Great Britain and populations of raccoons can now be found in some regions of Germany, the Caucasus and Japan. Fur farm escapees such as coypu and American Mink have extensive populations in the Old World.
In the New World, populations of feral European cats, pigs, horses and cattle are common.
See also 
- Alfred Crosby
- Great American Interchange
- Guns, Germs, and Steel
- Population history of American indigenous peoples
- Pre-Columbian trans-oceanic contact
- Transformation of culture
- 1493: Uncovering the New World Columbus Created
- 1491: New Revelations of the Americas Before Columbus
- Nunn, Nathan; Qian, Nancy (2010). "The Columbian Exchange: A History of Disease, Food, and Ideas". Journal of Economic Perspectives 24 (2): 163–188. doi:10.1257/jep.24.2.163. JSTOR 25703506.
- Crosby, Alfred W. The Columbian Exchange: Biological and Cultural Consequences of 1492. Westport, Conn.: Greenwood Press, 1972.
- de Vorsey, Louis (2001). "The Tragedy of the Columbian Exchange". In McIlwraith, Thomas F; Muller, Edward K. North America: The Historical Geography of a Changing Continent. Lanham, MD: Rowman & Littlefield. p. 27. "Thanks to…Crosby's work, the term 'Columbian exchange' is now widely used…"
- "The Impact of the Potato", History Magazine
- "Super-Sized Cassava Plants May Help Fight Hunger In Africa", The Ohio State University
- "Maize Streak Virus-Resistant Transgenic Maize: an African solution to an African Problem", Scitizen, August 7, 2007
- "China's Population: Readings and Maps", Columbia University, East Asian Curriculum Project
- This transfer reintroduced horses to the Americas, as the species had died out there prior to the development of the modern horse in Eurasia.
- "The Story Of... Smallpox – and other Deadly Eurasian Germs", Guns, Germs and Steel, PBS Archived 17 January 2010 at WebCite
- A History of the Tomato in Italy Pomodoro!. David Gentilcore (New York, NY: Columbia University Press, 2010).
- Hoddle, M. S. "Quagga & Zebra Mussels". Center for Invasive Species Research, UC Riverside. Retrieved 2010-06-29.
- Elusive Lager Yeast Found in Patagonia, Discovery News, Aug 23, 2011
- The Columbian Exchange: Plants, Animals, and Disease between the Old and New Worlds in the Encyclopedia of Earth by Alfred W. Crosby
- Worlds Together, Worlds Apart by Jeremy Adelman, Stephen Aron, Stephen Kotkin, et al.
- New study blames Columbus for syphilis spread from Reuters Jan 15, 2008
- Foods that Changed the World
- The Columbian Exchange study guide, analysis, and teaching guide