1,700 Ancient Viruses Discovered in Himalayas, Dating Back 41,000 Years

A recent study has revealed that the Himalayas harbor nearly 1,700 ancient virus species, with around three-quarters of them previously unknown to science. The findings, published in the journal *Nature Geoscience*, come from the analysis of viral DNA preserved in the ice cores of the Guliya Glacier, located on the Tibetan Plateau, nearly four miles above sea level. Researchers hope this discovery will shed light on how viruses adapt to climate changes and predict how current viruses might evolve in the future.

The discovery was made in 2015, but the results were only recently published. Study co-author ZhiPing Zhong, a research associate at the Byrd Polar and Climate Research Center at The Ohio State University, highlighted the uniqueness of the study. “Before this work, the connection between viruses and large-scale changes in Earth’s climate was largely unexplored,” Zhong said. He emphasized the value of glacial ice in virus and microbe research, noting that the limited availability of such materials makes this research particularly precious.

With climate change causing glaciers to melt at an alarming rate, scientists are concerned about losing the historical data stored in these ice formations. Some glaciers in the Himalayas, Alps, and Andes have already lost significant ice, and three of the ice cores in the study were sourced from glaciers that no longer exist today. Lonnie Thompson, a paleoclimatologist and glaciologist at Ohio State University, underscored the urgency of the research, stating, “Our mountaintop glaciers and the history they contain are disappearing at an accelerating rate as global temperatures continue to rise.”

The viruses discovered in the study span nine distinct time periods, covering three cold-to-warm cycles over the past 41,000 years. This isn’t the first time ancient viruses preserved in permafrost have been uncovered, raising concerns among scientists about the potential risk of these ancient pathogens infecting humans as more glaciers melt.

The research also reveals insights into how these ancient viruses adapted to climate changes over thousands of years. One of the viruses identified dates back around 11,500 years, a period marking the transition from the cold Last Glacial Stage to the warmer Holocene epoch, which we currently live in. Additionally, some viruses found in the ice cores seem to have origins outside the immediate region, with a quarter of them sharing similarities with species found in other parts of the world. Zhong suggested that some of these viruses may have been transported from regions like the Middle East or even the Arctic.