37,000 Years of Disease Traced Through Ancient DNA
We often think of pandemics as modern problems, but our relationship with disease is far older than we realize.
A new international study led by researchers at the University of Copenhagen has mapped the genetic traces of infectious diseases across 37,000 years, using ancient human DNA from archaeological sites across Eurasia. The findings paint a vivid picture of how pathogens have shadowed humanity through the ages, evolving alongside us, and sometimes, because of us.
By analyzing the genomes of more than 3,400 ancient individuals, the team found telltale markers of exposure to pathogens like tuberculosis, leprosy, hepatitis B, and even early coronaviruses. These weren’t just isolated cases. The study suggests that disease pressure has been a persistent evolutionary force, shaping human biology and immunity for tens of thousands of years.
And a major turning point? Animals.
“Our shift to agriculture and animal domestication fundamentally changed the disease environment,” explains geneticist Morten Allentoft. Once humans began living in close quarters with livestock, new zoonotic pathogens, diseases that jump from animals to humans, emerged and rapidly spread.
One of the study’s key revelations is how some regions saw dramatic rises in immune-related genetic variants, suggesting waves of infectious outbreaks that left genetic scars in ancient populations. These evolutionary signals are still detectable in people alive today.
What’s striking is how this long timeline reshapes our understanding of public health. “We’re not just dealing with modern infections,” says Allentoft. “We’re carrying the genetic memory of ancient epidemics.”
This research is the most comprehensive of its kind to date, combining archaeology, evolutionary biology, and genomics to build a timeline of human disease that stretches back into the last Ice Age.
It’s a reminder that pandemics aren’t new. They’re ancient companions, silent forces that have nudged human evolution, rewired our immune systems, and followed us from caves to cities.
And as history shows, once we opened the door to animals, we also let in a world of microbes that we’re still learning to live with.