It is called a Colombian exchange to the process occurred between the XV and XVI centuries in which agricultural products and other foods of the New World (the American continent) in the Old World (Europe, Africa and Asia) and vice versa were made known. A broader definition also includes technological advances, demographics and even diseases.
The most lethal of the pathogens introduced by the Europeans was smallpox, which at times incapacitated so many adults while deaths from hunger and starvation ran as high as deaths from the disease, and in several cases, whole tribes were extinguished .
Since Europe and the eastern hemisphere were much more developed at the time of Columbus' voyages, the Americas received more new species and innovations in the Columbian exchange.
The conquest of America was a demographic disaster, an ecological catastrophe. Several tens of millions of indigenous people disappeared from their own map in less than a century. For example, 90% of the Caribbean and Arawak population died in the twenty years following the arrival of Christopher Columbus and his men in 1492.
