The collapsed Fuluchter Peak in Austria (middle right) reduced the height of the mountain by 19 meters, which scientists blame on melting permafrost. (Sean Gallup/Getty Images)
Text/Reporter Chen Ting
Scientists warn that “time traveling” pathogens released by thawing permafrost could pose a threat to modern ecosystems.
Permafrost (Permafrost) is generally distributed in high latitudes or high altitude areas, such as Greenland, Alaska, Siberia, the Tibetan Plateau and northern Canada. It is a hard frozen soil layer composed of soil, sand and rocks. The lower layer is frozen in summer. Still frozen.
Research has found that these permafrost layers contain microorganisms that have been dormant for a long time. As the permafrost thaws, these ancient pathogens may return to the ecosystem.
about1%ancient virusFear of damaging ecosystems
In order to have a clearer understanding of possible ecological impacts, an international research team recently published a study in the journal PLOS Computational Biology, establishing a model for the interaction between ancient viruses and modern bacteria. Digital model.
Through tens of thousands of iterative simulations, the research team tracked how the virus affected the species diversity of bacterial communities. It was found that approximately 1% of ancient viruses caused significant damage to the digital ecosystem.
In some simulations, ancient viruses reduced bacterial diversity across entire ecosystems by 32%. Viral invaders not only survive but evolve over time, throwing ecosystems out of balance.
The researchers used the “Avida” software to simulate whether the pathogen could successfully penetrate the ecosystem. In a two-dimensional grid, bacteria interact with their environment, competing for energy and space. Bacterial competitors find their own niche to multiply and survive in the cycle.
During this process, small errors in the reproduction process create genetic diversity and form more complex ecosystems. When a virus enters this environment, it must draw energy from a suitable bacterial host, which then dies because it cannot obtain the energy it needs to survive or reproduce.
dormant for tens of thousands of yearsAre ancient pathogens still contagious?
Over the past 20 years, more and more research has been devoted to understanding the consequences of thawing permafrost in the Arctic, such as: a 2022 study by the National Aeronautics and Space Administration (NASA) investigating the carbon emission impacts of thawing emergencies, and -Jean-Michel Claverie A decade of research identifying potentially infectious pathogens in permafrost.
Claverie is Emeritus Professor of Medicine and Genomics at the Faculty of Medicine at Aix-Marseille University. In 2014 and 2015, he resurrected so-called “zombie” viruses from the permafrost. Although they are 48,000 years old, some of them can still replicate in the amoeba, causing them to burst and release new viruses. Particles.
In a study in February 2023, Claverie and his team reported that five new families of ancient viruses are able to infect amoeba. These studies demonstrate that ancient pathogens could still be infectious despite being dormant for tens of thousands of years.
The lead author of the report is Giovanni Strona and co-author Corey Bradshaw.
Stroner said that in a successful invasion event, species diversity could be lost by as much as 32 percent. This does not mean that the virus killed 1/3 of the bacteria in the virtual ecosystem, but that the ecosystem faced a shock and bacterial diversity decreased by 32%.
Bradshaw said that while a 1% chance may seem low, four sextillion (10 to the 21st power) cells escape from permafrost every year, far exceeding the number of stars in the Milky Way. “The chances of this happening are very high.”
Although modern organisms, including humans, have almost no natural defense mechanisms against ancient pathogens, permafrost areas are sparsely populated. If ancient pathogens escaped in some way, it would still be difficult to find people to infect. ◇
