Overview

Dozens of ancient viruses remain inside the glacial ice that formed 15,000 years ago on the Chinese Tibetan Plateau. A team of researchers from Ohio University has analyzed ice samples taken in 2015 and has been surprised to find a completely unknown variety of viruses that could have been lethal to our human ancestors.

The science and other stuff to know

The study of glacial ice is of enormous importance in fields such as environmental sciences, geology, and biology since stages of our planet’s past have been captured inside it: microorganisms, components present in the atmosphere, dust, and ashes, among others. The old ice sheets are compacted by the weight of the most recent ones, which means the researchers can interact with the different geological stages and reconstruct a scenario from millennia ago by extracting a longitudinal cylinder from the layers.

The 15,000-year-old ice was collected from a Tibetan glacier at an altitude of 6,700 meters (22,000 feet) and serves as a model sample because it contains 33 previously unknown virus species. The ice, far from killing them, acts as a cryogenesis chamber that preserves the genetic sequence of these organisms, waiting one day to be released to reactivate, according to the study published in the journal Microbiome.

Viruses are organisms that do not share genetic traits; that is, no pattern groups them and differentiates them from other organisms, so their classification is a cumbersome task. The researchers were able to correlate four of the viruses discovered in the Tibetan ice with previously identified virus species, concluding that at least these did not come from humans or animals, and only infected bacteria.

So what?

This practice involving the study of frozen organisms in ancient ice is relatively new and has the potential to answer questions in various fields. One of the most growing concerns is linked to the fact that global warming is raising the average temperature of the planet, causing ancient ice to melt and hundreds of species and viruses unknown to our modern human bodies to break free of their lethargy and cause infections. “We know very little about viruses and microbes in these extreme environments, and what is actually there,” said Thompson, a co-author of the paper, in a press release.

Matthew Sullivan, who also took part in the study, stated that the techniques were used to better understand how some organisms interact with extreme cold and use it to their advantage in order to survive over time. Creating a robust model in this way could aid astrobiologists in detecting life on Mars or icy craters on our and Jupiter’s moons.

What’s next?

The study concludes that it is necessary to deepen the research related to the forms of extremophile life that live in super-frozen environments, and anticipate their adaptation to the current environment if there is a significant thawing of the ancient ice: “The Earth will is now fully in the Anthropocene, and human activities are impacting the planet and its interconnected ecosystems in a way that no species has before Fortunately, the application of advanced research capabilities to the intensive study of biotic and abiotic information derived from the ice core may reveal the main drivers of natural and anthropogenic variations in microbial evolution.”