Defenses, Then and Now

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Scholars had long blamed European settlers for bringing a number of diseases to the New World, including tuberculosis (TB), which decimated local Indigenous populations.

But now, a new genetic study found that Indigenous people living in South America’s Andes Mountains adapted to TB long before the arrival of Europeans more than 500 years ago, Forbes reported.

For their study, an international research team sequenced the genomes from blood samples of 15 present-day Indigenous individuals living at altitudes of more than 8,000 feet in several different Ecuadorian provinces.

The team initially sought to understand how the Indigenous peoples of Ecuador adapted to living at high altitudes. Instead, they discovered strong signals for biomarkers that are switched on in modern humans during an active TB infection.

They also found that these “started to uptick a little over 3,000 years ago,” said lead author Sophie Joseph in a statement.

“That’s an interesting time because it was when agriculture began proliferating in the region,” she added. “The development of agriculture leads to more densely populated societies that are better at spreading a respiratory pathogen like TB.”

The new findings add to a growing body of evidence suggesting that TB was already present in South America before the Europeans’ arrival: A past study found evidence of TB in the remains of 1,400-year-old Andean mummies in Peru.