USA HISTORY

Detailed explanation-1: -The spread of disease. Possibly the most dramatic, immediate impact of the Columbian Exchange was the spread of diseases. In places where the local population had no or little resistance, especially the Americas, the effect was horrific. Prior to contact, indigenous populations thrived across North and South America.

Detailed explanation-2: -New diseases were introduced to American populations that had no prior experience of them. The results were devastating. These populations also were introduced to new weeds and pests, livestock, and pets. New food and fiber crops were introduced to Eurasia and Africa, improving diets and fomenting trade there.

Detailed explanation-3: -Physical and psychological stress, including mass violence, compounded their effect. The impact was most severe in the Caribbean, where by 1600 Native American populations on most islands had plummeted by more than 99 percent. Across the Americas, populations fell by 50 percent to 95 percent by 1650.

Detailed explanation-4: -Europeans brought deadly viruses and bacteria, such as smallpox, measles, typhus, and cholera, for which Native Americans had no immunity (Denevan, 1976). On their return home, European sailors brought syphilis to Europe.

Detailed explanation-5: -Diseases. The most devastating component of the Columbian exchange was the transfer of Old World diseases to the Americas. Among the lethal germs were smallpox, measles, mumps, whooping cough, chickenpox, typhus, and influenza.