Final answer:
The unintended consequences of the exchange between the Eastern and Western hemispheres included the spread of diseases to the Native Americans and the introduction of new plants and animals in both hemispheres.
Step-by-step explanation:
The unintended consequences of the exchange of plants, pests, and diseases between the Eastern hemisphere (Old World) and the Western hemisphere (New World) were significant and had lasting effects.
One major consequence was the spread of diseases from Europe to the Americas. Native Americans had not previously been exposed to these diseases and therefore did not have any immunity.
As a result, epidemics of diseases like smallpox, measles, and influenza wiped out a large portion of the Native American population, leading to population decline and cultural devastation.
Another consequence was the introduction of new plants and animals to both hemispheres. Europe brought crops like maize, potatoes, and cassava to the Americas, which helped feed growing populations.
Similarly, European animals like pigs, sheep, and chickens thrived in the Americas, providing a new source of protein. However, these introductions also had ecological impacts, as native species were displaced and ecosystems were disrupted.
Overall, the exchange of plants, pests, and diseases between the Eastern and Western hemispheres had profound effects on both human populations and the environment.