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Scientists have resurrected a 'zombie' virus that spent 48,500 years frozen

Scientists have resurrected a 'zombie' virus that spent 48,500 years
Warmer temperatures in the Arctic are melting the region's permafrost and potentially reawakening viruses that, after lying dormant for tens of thousands of years, could endanger animal and human health.

While a pandemic caused by a disease from the distant past sounds like the plot of a science fiction movie, scientists warn that the risks, although low, are underestimated. Chemical and radioactive waste dating back to the Cold War, which has the potential to harm wildlife and disrupt ecosystems, could also be released during the meltdown.

To better understand the dangers posed by frozen viruses, Jean-Michel Claverie, a professor of medicine and genomics at Aix-Marseille University School of Medicine in Marseille, France, tested soil samples taken from Siberian permafrost to see if any viral particles contained in it are still infectious. He's looking for what he describes as "zombie viruses" - and he's found some.

The oldest was almost 48,500 years old, based on radiocarbon dating of the soil, and came from a soil sample taken from an underground lake 16 meters below the surface.

His efforts to discover viruses frozen in permafrost were partly inspired by a team of Russian scientists who in 2012 resurrected a wildflower from a 30,000-year-old seed tissue found in a squirrel's burrow. (Since then, scientists have also successfully brought ancient microscopic animals back to life.)

Last year, a team of scientists published research on samples taken from Lake Hazen, a freshwater lake in Canada located inside the Arctic Circle.

Using a computer model analysis, they suggested that the risk of viruses spreading was higher near where large amounts of meltwater poured into the lake – a scenario that becomes more likely as the climate warms.