A dramatically widespread exchange of animals, plants, culture, human populations (including slaves), communicable disease, and ideas between the eastern and western hemispheres (old world and new world). it was one of the most significant events concerning ecology, agriculture, and culture in all of human history. christopher columbus first voyage to the americas in 1492 launched the era of large-scale contact between the old and the new worlds that resulted in this ecological revolution, hence the name columbian exchange. the columbian exchange greatly affected almost every society on earth. new diseases introduced by europeans, to which the indigenous peoples of the americas had no immunity, depopulated many cultures. on the other hand, 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 eurasia by the 18th century. new type of people resulted from columbian exchange a new kind of people were also created, such as mestizo, mulatto, zambo and lobo. social classes depended on race, with eurpean born whites on top and indians on the bottom. a new culture was made based on a mixture of european, african and native. zambo mixed african and amerindian ancestry. mestizo mixed european and native american heritage or descent. mullato denotes a person with one white parent and one black parent, or more broadly, a person of mixed black and white ancestry.