Scientists have discovered more than 1,700 viruses in Himalayan glaciers that are more than 41,000 years old.

Illustrative photos

Central Asia (CA) – Scientists examined a block of ice in the Himalayas and found that it contained the genomes of 1,705 viruses. They are more than 41,000 years old. This is according to a study published in the journal Nature Geoscience Write Popular science.

The scientists examined samples from the Gulia Glacier on the Tibetan Plateau, which is more than 6 kilometers above sea level. It contained about 50 times more information about the virus than scientists had ever gotten from the glacier.

The viruses obtained from the Gulia glacier core are prokaryotes. That is, they infect bacteria and archaea, not humans, animals or plants.

“Data like this are critical for asking any questions about what the Earth was like before. Collecting these 1,700 genomes now allows scientists working on glaciers elsewhere to uncover the stories in these freezers, so to speak,” explained microbiologist Matthew Sullivan, co-author of the study.

The scientists “extracted” all possible DNA from nine sections of the 310-meter-long ice core, each representing a different time range and climax period.

The youngest is only 160 years old, while the oldest is over 41,000 years old.

They extracted DNA in bulk from each sample and used metagenomic analysis to select as many viral strains as possible from the resulting genetic soup.

The scientists found that viral communities differed significantly depending on the climate conditions recorded at each depth and how long they stayed in the ice cores.

During Earth’s past cold periods, viruses from the Gullia glacier reverted to a similar but not identical composition. Each warming period gave rise to a whole new set of viral species.

The most diverse and unique mix of microbes emerged around 11,500 years ago, when Earth’s last ice age ended, showing how closely climate and bacteria are related.

Scientists compared these samples with known viruses. They found that more than 70% of the samples collected from the ice core were unique to Gulia Glacier. They have never been found on Earth before.

Only 12% of the viruses are known outside Asia.

But a small fraction (less than 1%) is recorded in non-glacial environments.

Scientists believe a better understanding of ancient frozen viruses could help predict our future.

“Having a genomic resource like this is key to our modeling capabilities,” said Matthew Sullivan.