Question

Explain how the global transfer of diseases held in America

Answer 1

The Portuguese and the Spanish had a strong firepower and army. But along with these, germs and viruses helped them in conquering parts of America. As America was isolated earlier, the original inhabitants had no immunity against the dreadful germs and viruses present in Europe.
The diseases once introduced, spread very fast. The diseases, like smallpox decimated whole communities, paving the way for the conquest of the colonisers.

Answer 2

Answer:

Europeans like Spaniards, Portuguese flowed into America after its discovery. 

The germs of smallpox were carried on their person.

The global transfer of disease in the pre-modern world helped in the colonization of the Americas because the native American Indians were not immune to the diseases that the settlers and colonizers brought with them.

The Europeans were more or less immune to smallpox, but the native Americans, having been cut off from the rest of the world for millions of years, had no defence against it. These germs killed and wiped out whole communities, paving the way for foreign domination.

Weapons and soldiers could be destroyed or captured, but diseases could not be fought against. But not diseases such as smallpox to which the conquerors were mostly immune.