Scientists fear that “time-travelling” pathogens could leak into the world as their icy prison in permafrost melts – and that they could ignite the next planet and destroy the environment.
Ancient viruses, trapped in permafrost for thousands of years, were able to survive and evolve to become the dominant free-living species, killing up to a third of bacterial hosts.
The stark revelation was made by researchers at the European Commission’s Joint Research Centre, who used computer simulations to find that about three percent of the virus-like pathogens became dominant after being released from the ice.
The new findings suggest that the risks posed by time-traveling pathogens — hitherto limited to science fiction stories — could be powerful drivers of environmental change and threats to human health.
Scientists fear that “time-travelling” pathogens could be leaked into the world as their icy prison in permafrost melts – and their escape would harm the environment. Pictured is an aerial view of the Arctic permafrost
In 2022, scientists announced they had resurrected a 48,500-year-old virus found in melting Siberian permafrost.
It is one of seven types of viruses in the permafrost that have been brought back to life after thousands of years.
The youngest was frozen for 27,000 years and the oldest, Pandoravirus yedoma, was frozen for 48,500 years.
While the viruses are not considered a risk to humans, scientists warn that other viruses exposed by melted ice could be “disastrous” and lead to new pandemics.
For example, Alaska’s permafrost once held the flu virus that spread in 1981, which could have sparked another outbreak.
There have been many studies on the impact of such pathogens on humanity, but the latest approach has been less studied: the environment.
The team quantified the ecological risks of these microbes using computer simulations by conducting artificial evolution experiments where digital virus-like pathogens from the past invaded communities of bacteria-like hosts.
Researchers had several hypotheses, such as that they expected ancient pathogens to be more susceptible to competition from modern ones.
“Modern hosts may also have escaped ancient pathogens during their coevolutionary history and may have retained their evolved resistance, challenging invaders to find susceptible hosts,” reads the study published in PLOS Computational Biology.
For example, Alaska’s permafrost once caught the flu virus that spread in 1981, which could have sparked another outbreak
In 2022, scientists announced they had revived a 48,500-year-old virus found in melting Siberian permafrost (pictured)
However, the team also hypothesized that modern hosts could have lost resistance.
“In that case, invaders may have an advantage over modern pathogens that are actively involved in the ongoing arms race between host and pathogen,” the team shared in the study.
The scientists used a program called Avida, an “artificial life system” of digital microorganisms.
After the simulations were created, the team then compared the effects of invading pathogens on host bacterial diversity with diversity in control communities where no invasion occurred.
The results of the simulations showed that the invader was more persistent than 33.6 percent of native pathogens.
While most dominant invaders had little effect on the composition of the larger community, about one percent of intruders produced unpredictable results.
“Some caused up to a third of host species to go extinct, while others increased diversity by as much as 12 percent compared to the control simulations,” the team shared in a press release.
“The risks from this one percent of released pathogens may seem small, but given the sheer number of ancient microbes regularly released into modern communities, outbreaks still pose a significant threat.”