ABSTRACT
The Columbian Exchange, a term coined in 1972 by the historian and geographer Alfred W. Crosby, Jr., refers to the worldwide, ongoing transfer of species between the Eastern and Western Hemispheres that began with Columbus’s first voyage in 1492. Indentured servants comprised between one-third and one-half of the Europeans who arrived in North America in the 1st century of colonization. Plants played a different role in the Columbian Exchange, most significantly as agricultural commodities. Transoceanic botanical introductions continue to reshape ecosystems. In the last half of the 19th century, the Para rubber tree became the principal source of latex, the main ingredient of rubber. Horses evolved in the Americas, went extinct there about 12,000 years ago, and were reintroduced by Columbus’s second voyage. Air travel, container shipping, and climate change have accelerated the Columbian Exchange, especially for invertebrates and microorganisms. Ballast is believed to have brought zebra mussels to North America, brook trout to Europe, and Mediterranean mussels to Africa.
