NewsRescue
Scientists in Russia have successfully resurrected a female roundworm that had been dormant for 46,000 years in Siberia. The worm sat in suspended animation for tens of thousands of years longer than any other animal studied to date, and once thawed, it began to reproduce.
The worm, a previously unknown species of soil nematode, was discovered in a soil sample near the remote settlement of Chersky in northeastern Siberia, according to Russian Academy of Sciences researcher Anastasia Shatilovich, who published her findings in the current issue of the journal PLOS Genetics. The dirt had not thawed since the late Pleistocene epoch, between 45,839 and 47,769 years ago, when it was taken from 40 meters below the surface.
Shatilovich’s team was successful in reviving the nematode, which subsequently began reproducing through a mechanism known as parthenogenesis, which does not require a mate.
While scientists have long known that many species may survive indefinitely by turning down their metabolisms, they had previously only been able to resuscitate soil nematodes that had been frozen for several dozen years. Other species have fared better, with the previous record established in 2021, when ancient bdelloid rotifers, minute multicellular organisms, were resurrected after 24,000 years in Siberian permafrost.
Although the nematode is no longer living, Shatilovich and her colleagues have produced 100 generations of its descendants.
“By adapting to cope with extreme conditions, such as permafrost, for short periods of time, the nematodes may have gained the ability to remain dormant over geological timescales,” according to a PLOS Genetics statement.
Siberia’s icy tundra also harbors an unknown number of ancient viruses, one of which was recently revived after 48,500 years by a team of researchers. Russia has warned that continued permafrost thawing due to climate change could release these hidden germs on the world. Thawing soil that has been firmly frozen for years or millennia may still contain “some viable spores of ‘zombie’ bacteria and viruses,” Nikolay Korchunov, a senior Russian Arctic Council delegate, said RT in 2021.