Frozen in time: Scientists discover 1,700 ancient viruses on the Tibetan Plateau

A new study published in Nature Geoscience has discovered a treasure trove of ancient viral DNA in the Guliya Glacier of the Tibetan Plateau, offering new insights into Earth's climate history.

Researchers at Ohio State University have identified nearly 1,700 species of viruses in ice core samples, about three-quarters of which were previously unknown to science.

Located at an altitude of over 6,000 metres in the northwestern Tibetan Plateau, the Guliya Glacier has long been a valuable archive for paleoclimate research.

By analyzing ice cores from this glacier, scientists were able to reconstruct viral DNA fragments that provide snapshots of microbial life during three major cold-warm transitions over the past 41,000 years.

Lead author ZhiPing Zhong emphasized the importance of this research, explaining: “Before this work, the relationship between viruses and large-scale climate change on Earth was largely unexplored.”

The study shows that these ancient viruses, although inactive and harmless to humans, played a crucial role in the adaptation of their microbial hosts to extreme environmental conditions.

One of the most notable finds was a distinct viral community dating back about 11,500 years, coinciding with the transition from the last ice age to the warmer Holocene period. This discovery suggests a possible link between viral communities and climate change.

Using cutting-edge sequencing technologies, the research team also found that while most of the viruses are unique to the Guliya Glacier, about a quarter share similarities with organisms from other parts of the world, suggesting the potential for long-distance transmission of these microorganisms.

As global warming accelerates the melting of glaciers, scientists are trying to collect and analyze these ice cores before they disappear. Co-author Lonnie Thompson emphasized the importance of this work, describing it as “a new tool that can answer fundamental climate questions that we would not have been able to answer otherwise.”

The study's findings not only contribute to our understanding of Earth's climate history, but may also help predict how modern viruses might respond to future ecosystem warming.

In addition, these techniques could potentially be useful in the search for microbial life in extraterrestrial environments such as the ice fields of Mars.