European colonization and global trade following his 1492 voyage. Some of the exchanges were deliberate while others were unintended. Communicable diseases of Old World origin resulted in an 80 to 95 percent reduction in the Indigenous population of the Americas from the 15th century onwards, and their near extinction in the Caribbean.
end partial quote from: Columbian Exchange.
So, open human contact with alien groups might do the same to us here and now as well.
What I learned here that I didn't know is that basically the Caribbean populations basically almost went extinct. So, likely up to 99% of the Caribbean populations just died at that time since they had no immunity at all to European plagues and diseases caused by too many people living too close together without proper sanitation in Europe.
