Similar events have occurred. The Black Death (bubonic plague) spread over a wide area several times.
In recent times, plane travel has spread several diseases.
Question 2.
Is the “Columbian Exchange” a unique event, or have similar events occurred throughout world history? Is there a point at which a difference in scale – the sheer quantity of biota that travel between widely separated areas – makes such an exchange radically different than the relatively routine exchange of, for example, flu viruses between populations?
2 answers
Anybody know the answer to the second question?