<P> The Columbian Exchange was the widespread transfer of plants, animals, culture, human populations, technology, and ideas between the Americas and the Old World in the 15th and 16th centuries, related to European colonization and trade after Christopher Columbus's 1492 voyage . Invasive species, including communicable diseases, were a byproduct of the Exchange . The changes in agriculture significantly altered and changed global populations . However, the most significant immediate impact of the Columbian Exchange was the cultural exchanges and the transfer of people between continents . Furthermore, a byproduct of the Columbian Exchange was the Atlantic slave trade, where as many as 12.5 million enslaved African people were forcibly transferred as a labor source to other regions . </P> <P> The new contact between the global population circulated a wide variety of crops and livestock, which supported increases in population in both hemispheres, although diseases initially caused precipitous declines in the numbers of indigenous peoples of the Americas . Traders returned to Europe with maize, potatoes, and tomatoes, which became very important crops in Europe by the 18th century . </P>

What were the colombian exchanges and how did they affect the world
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