Disease-riddled Europeans, carrying tuberculosis across the Atlantic, have long been blamed for wiping out huge populations of Native Americans.
But new research has found that the deadly bugs which killed millions were probably spread by seals and sea lions, long before Christopher Columbus first arrived in the New World in 1492.
A study which looked at tuberculosis strains in bones discovered in Peru found they were closely linked to those found in sea mammals.
The research shows that tuberculosis is likely to have spread from humans in Africa to seals and sea lions, who then carried the disease to South America and transmitted it to Native populations long before Europeans landed on the continent...I can't comment on the history of South America; in North America it's true that there was evidence of depopulation (in the desert Southwest and at Cahokia) before the arrival of Europeans), but there is also well-documented eyewitness evidence of the ravages of diseases brought by the first Europeans.
"Our results show unequivocal evidence of human infection caused by sea lions and seals in pre-Columbian South America.
“Within the past 2,500 years, the marine animals likely contracted the disease from an African host species and carried it across the ocean to coastal people in South America.”
I don't doubt that seals may have spread mycobacterial disease to humans (perhaps nontuberculous mycobacteria, labeled "tuberculosis" in the article), but I can't envision any mycobacteria (even M.Tb) causing the biblical-level depopulations experienced in North America.