Perhaps the most obvious ecological change in the Americas after the arrival of the Europeans was the introduction of a series of diseases that practically wiped out the American Indians by the thousands. Disease was undeniably the most powerful weapon wielded by European conquerors. Because they were American Indians were isolated from the rest of human civilization, “the fatal diseases diseases of the Old World killed more effectively in the New, and the comparatively benign diseases of the Old World turned killer in the new.” In a relatively short amount of time, the New World lost a majority of its previous human inhabitants, gained a new population that would inhabit its land up to modern times, and was introduced to a series of malignant
