A groundbreaking study has uncovered nearly 1,700 ancient virus species preserved in the ice of the Himalayas. According to research published in the journal Nature Geoscience, about three-quarters of these viruses were previously unknown to science. This discovery offers a rare glimpse into how viruses have adapted to climatic shifts over thousands of years and raises concerns about how they might evolve in the future.
The discovery in the Guliya Glacier
The viruses were found in ice cores extracted from the Guliya Glacier, located on the Tibetan Plateau nearly four miles above sea level. This remote glacier has preserved viral DNA for millennia, offering scientists a unique opportunity to study the ancient pathogens.
“Before this work, how viruses linked to large-scale changes in Earth’s climate had remained largely uninvestigated,” said ZhiPing Zhong, a co-author of the study and a research associate at the Byrd Polar and Climate Research Center at The Ohio State University. “Glacial ice is so precious, and we often don’t have the large amounts of material required for virus and microbe research.”
The study, which began in 2015, has only recently been published, marking a significant step forward in understanding the role of viruses in Earth’s climatic history.
Climate change and the threat to permafrost
As global temperatures rise, the melting of glaciers is accelerating, threatening to destroy the valuable information stored in permafrost. Glaciers in the Himalayas, the Alps, and the Andes are particularly vulnerable, with some already having lost significant amounts of ice. “Three of the ice cores in our collection come from glaciers that no longer exist in the real world,” said Lonnie Thompson, a paleoclimatologist and glaciologist at Ohio State University. “Our mountain-top glaciers and the history they contain are disappearing at an accelerating rate as global temperatures continue to rise.” The urgency of the situation has prompted scientists to extract and study as much data as possible before these ancient archives are lost forever.
Reconstructing 41,000 years of viral history
The viruses discovered in the Guliya Glacier span “nine-time horizons, covering three cold-to-warm cycles over the past 41,000 years,” according to the paper. This finding offers unprecedented insights into how these ancient viruses adapted to changing climates and evolved over millennia. One of the viruses was found in ice dating back approximately 11,500 years, during a transitional period from the Last Glacial Stage to the warmer Holocene epoch, which continues today. Scientists also believe that some of these viruses may have originated from distant regions, as at least a quarter of them share similarities with species found elsewhere. “That means some of them were potentially transported from areas like the Middle East or even the Arctic,” Zhong explained.
Concerns and future implications
This is not the first time that ancient viruses have been discovered in permafrost, but the increasing rate of glacial melt raises concerns about the potential risks to human health. As more glaciers melt, the possibility that one of these ancient viruses could infect humans grows. The study underscores the importance of understanding the history of viruses in the context of Earth’s changing climate. As scientists race against time to uncover and study these ancient pathogens, the findings could offer critical insights into how viruses might evolve in response to current and future environmental changes.