Answer:
introduction of new animals and crops to North America
Explanation:
Since the early 1500s, Europeans have transported old world species to their new settlements in the Western Hemisphere, as well as to other parts of the world. The manifestoes of Christopher Columbus' second and subsequent voyages, for example, mention the deliberate transportation of species considered potential crops and livestock. Global trade has grown astronomically since then, providing an opportunity for the corresponding growth of biological invasions. Consequently, biological invasions can be viewed as a predominantly post-Columbian event. Put in perspective, the movement of organisms caused by humans, accidentally or deliberately in the last 200 to 500 years, undoubtedly dwarfs in frequency and impact the movement of organisms by natural forces at any 500-year period in Earth's history.
