Christopher Columbus may have brought smallpox that devastated the Native American populations, but according to some scientists, they've got him (and those Europe colonists) back by returning the favor with syphilis:
Armelagos, a pioneer of the field of bioarcheology, was one of the doubters decades ago, when he first heard the Columbus theory for syphilis. “I laughed at the idea that a small group of sailors brought back this disease that caused this major European epidemic,” he recalls.
While teaching at the University of Massachusetts, he and graduate student Brenda Baker decided to investigate the matter and got a shock: All of the available evidence at the time actually supported the Columbus theory.
“It was a paradigm shift,” Armelagos says. The pair published their results in 1988.
In 2008, Harper and Armelagos published the most comprehensive comparative genetic analysis ever conducted on syphilis’s family of bacteria. The results again supported the hypothesis that syphilis, or some progenitor, came from the New World.