How did the Columbian Exchange impact both the New and Old Worlds?
The Columbian Exchange had profound ramifications for both the Old and New Worlds. The most immediate effect of the collision between Europeans and Americans was the introduction of infectious diseases by Europeans, diseases for which Indians had no immunity. As a result, millions of Indians perished in massive pandemics. This was only the first shock wave of what historian Alfred Crosby has called a "trend toward biological homogeneity" that was "one of the most important aspects of the history of life on this planet since the retreat of the continental glaciers." What Crosby meant was that American flora and fauna flooded into Europe, and vice versa. Animals such as cattle, horses, and pigs, and crops such as wheat, sugar cane, and rice permanently altered the diets and agriculture of the New World. Similarly, the potato, tobacco, and maize quickly made their way into European diets. The ecological impact, especially in the New World, was dramatic. New European weeds spread like wildfire, and animals, especially hogs, destroyed crops with impunity.