When Columbus accidentally "discovered" the Americas for Spain, he also reunited two halves of the world which had been effectively separated from each other since the end of the Pleistocene: the half of North and South America, and the other half of Asia, Africa and Europe, the eastern and western hemispheres of the earth. These two halves had each gone their own way in cultural development, and though there were differences, the results were in many ways the same. Each had developed horticultural tribes, then chiefdoms, then agrarian states that included not only the political state but class stratification, full-time occupational specialists, widespread trade and market exchange, and monumental public works. Brutal wars of conquest, as well as slavery and human sacrifice, were found in both hemispheres prior to 1492.
There were significant differences, and these differences, once exchanged, were to influence the rest of history. The most significant parts of what is called the Columbian exchange are discussed in this lesson.
The role of infectious diseases has already been noted many times. Most of these diseases originated with domesticated animal viruses or bacteria that mutated in ways that made human to human transfer possible. The Americas lacked the wild animals to domesticate, particularly cattle, pigs, sheep, goats, and ducks, and hence lacked these diseases. For humans in most of Asia, Europe, and Africa there was close to 10,000 years to evolve some genetic immunity to the most important of these diseases--particularly smallpox, measles, influenza, and typhoid. Columbus and the Europeans who followed him ended the biological isolation of the Americas, with devastating consequences. As noted earlier it is estimated that within 300 years 90-95% of the Native Americans in North America had died, primarily due to introduced diseases; estimates for South America as a whole are lacking, but in certain areas the death rate was also close to 90%.
The weapon of disease was not well recognized by the early Europeans, nor consciously used by any until a few instances in the 19th century (when disease was either consciously introduced or allowed to take its course). In the Caribbean, the Spanish (and not just the missionary priests) would have greatly preferred that the Native Americans remained alive, in order to work the sugar plantations that were quickly developed. In the Caribbean however the 95% death rate among the original inhabitants was achieved by 1600. Lacking an indigenous labor force, the Spaniards turned to importing black Africans, primarily from western Africa, as slaves. This began the slave trade that was central to European colonies in the Americas up to the 1880s, by which time 9.5 million Africans had been enslaved in the "new world".
There may have been a couple of diseases, or at least variants of those diseases, that the Europeans acquired in the Americas and took back to the "old world", though the evidence is not clear. The diseases are yaws and the sexually transmitted disease of syphilis. Both are caused by the spirochete bacterium Treponema pallidum and there are both mild and virulent variants of each disease. Both diseases start as skin lesions, and progress to extensive destruction of soft tissue and ultimately bone. There is ample skeletal evidence of yaws in both hemispheres, both from skeletal evidence, historical descriptions in the "old world", and artistic evidence, such as Moche pots, in the "new". Some scientists believe that for both hemispheres there is also evidence of syphilis.; others argue that there is good evidence only in one hemisphere, but disagree on which. In any case, shortly after Columbus returned from his first voyage there was a virulent outbreak of what was definitely syphilis in Europe, the first recorded instance in 1494. People developed so many sores that their flesh was recorded as literally falling from their bones, and they died in a few months. Often called the "Spanish disease", the virulent form of syphilis spread throughout Europe in the 16th century. Some scientists believe that at the very least, a new variant of syphilis was introduced by Spanish conquistadors returning from the Americans, causing the outbreak.
In many ways, sugarcane was the most important cultivated plant transferred from the "old" to the "new" world. Sugarcane was originally indigenous to island southeast Asia, and was probably first domesticated in New Guinea close to 8,000 BC. By AD 700 sugarcane had been brought to the Mediterranean area by the Islamic expansion and trade, and the European Crusades to Jerusalem in the 1000's brought back an increased desire for sugar throughout Europe. A tropical crop, sugarcane could not be easily grown in most of Europe, but it was taken by Columbus to the Caribbean on his second voyage in 1493. The Spaniards in the Caribbean islands quickly discovered that trade in sugarcane was an excellent long term money-making proposition in the more tropical regions of the Americas, and established sugarcane plantations throughout the area; the Portuguese were to do the same in Brazil. The popular alcoholic beverage rum was produced from sugarcane, which helped to fuel the demand. In addition, the cacao bean was indigenous to the American tropics and had already been domesticated by Native Americans (remember that cacao beans were sometimes used as money in Mesoamerica); chocolate quickly became a much desired item in the "old world".
It was sugarcane that became the major commodity stimulating the slave trade from west Africa to the Americas. More slaves were brought to the Americas in the name of sugar than ever were in the name of cotton. The slave trade was not to be abolished throughout the Americas until the 1880's, and its abolishment was to lead to the importation of many low-wage workers from China, India, and southeast Asia into the Caribbean. Hawaiian history has also been much influenced by the sugar trade. The mid-19th century establishment of sugarcane plantations in Hawai'i (mostly by people from the United States) brought workers from China, Japan, Portugal, and the Philippines to these islands. The United States and Europe remain today the biggest consumers of sugar in the world.
Besides sugarcane, many plants and animals were introduced into the Americas by the Europeans. Animals included cattle, pigs, sheep, goats, and chickens; none however were more important than the horse. Horses were of great importance to the mobility and ultimate success of the Spanish conquistadors, as noted in the two previous lessons. Early in the 1500's and subsequently as the Spaniards expanded northward from central Mexico, wild populations of horses started to develop in the great grasslands of what is now the western half of the United States.
Up until that point, the great plains themselves were sparsely populated. The were a few nomadic foragers, but the bulk of the population were horticultural tribes practicing slash and burn farming in the major river valleys. Without the metal plow and draft animals, it was impossible to cut through the thick sod in order to farm the central prairies and plains which today produce so much food in the United States. The Native Americans in the area however were quick to domesticate the wild horses as they started to appear in the plains, and to use the horse to hunt the bison or American buffalo which roamed the grasslands. After 1600, the well known plains Indian tribes had started to develop; many of them gave up horticulture to make the transition. It is these tribal people which many Americans think of when they think of Native Americans, even though it was a short-lived lifestyle made possible only by the introduction of the horse. In the eastern half of what is now the United States, as well as in the American southwest, almost all Native Americans were living in horticultural tribes or complex chiefdoms. (Refer to Unit 2)
The list of plants that the Americas contributed to the rest of the world includes squash, beans, chili peppers, tomatoes, peanuts, sweet potatoes, the avocado, pineapple, and cacao or cocoa. It is hard to imagine the world's diet without all of them, but without question the contribution of maize or corn, manioc, and potatoes had the greatest impact on the rest of the world. Corn grows quickly, prospers in a variety of climatic zones, and grows well in areas too wet for wheat, and too dry for rice. It produces almost twice the calories per acre of wheat. The transfer of this crop to Africa allowed for the enormous increase in population in that continent, and maize flour still is a primary food source throughout the continent. While its increase in cultivation in Africa supported the population growth necessary for the slave trade, maize also provided the perfect food to store on slave ships.
In west African countries where maize is not today the primary food crop, manioc takes its place. Manioc grows readily in tropical climates, and manioc or cassava flour has fueled the increase in population in Africa since it was first introduced by the Spaniards. Manioc ranks third in the world today in terms of a carbohydrate rich food, and more than half of the almost 200 tones produced each year is grown in Africa.
At least seven species of potato (not including the sweet potato) were cultivated in South America, primarily in the Andean uplands. The potato was carried back to Europe at least by 1536. Once in Europe, it was soon discovered that potatoes could easily grow in the poor soils and colder climate common to northern Europe, and potatoes quickly became a staple of the poor. In addition, potatoes contributed to an increase in Europe's population and proved a very productive food source, freeing thousands of peasants to become the laborers of the Industrial Revolution. The peasants in Ireland came to rely almost exclusively on the one crop, potatoes, and when between 1845-1852 a blight struck the crop, there was wide-spread starvation. It is estimated that during those years at least a million Irish died of starvation and diseases associated with malnutrition; another million emigrated, with more to follow, primarily going to the United States. Today, the potato is a common food in both Europe and the United States as well as in many other nations; currently the world's largest producer and consumer of potatoes is China.
Moche Stirrup Potato Pot; Vincent Van Gogh's Malnourished Flemish Peasants, in 1885 Painting The Potato Eaters [Public Domain]
The reunification of humans in the two halves of the world destroyed the cultures and most of the people of one half, and forever changed, and ultimately enriched, the lives of the people in the other half. None of the events of more recent history would have been possible without it.