The regions of the globe that contain permafrost, a kind of frozen ground, are real theme parks for scientists. With the glaciers melting, scientists have already been able to identify them animal bodies From the past practically intact even microscopic microorganisms Which came back to life after years of freezing. Now, researchers at Ohio State University in the US have identified dozens of viruses in two ice samples taken from the Tibetan Plateau in China.
The analyzed ice belongs to the Julia Ice Sheet, located at an altitude of 6.7 kilometers above sea level. Ice sheets accumulate annually. When they form, they trap everything in the atmosphere, be it gases, dust, or microorganisms. In this case, the researchers found 33 viruses that were trapped by ice 15,000 years ago. Of these, 28 are new to science. The full study was published in the scientific journal microbiome.
Through genetic analysis of viruses, scientists discovered that some microorganisms were phages, that is, they infect bacteria. Moreover, their genetic signatures indicate the ability to infect cells in cold environments, helping them thrive in harsh environments such as the ones in which they are found.
Viruses are found in permafrost They were related to infectious agents that parasitize the strains MethylobacteriumBacteria that are normally found in soil or in plants. Tibetan glacier viruses would have originated in one of these two environments, rather than in animals or humans.
Finding evidence of the past in permafrost is great for studying Earth evolution, but it also raises concerns. Melting glaciers can release microorganisms into the environment, which may pose risks to human health. Moreover, the decrease in ice causes more methane and carbon, which was previously held by the soil, to be released into the environment, intensifying the greenhouse effect.