Scientists have resurrected a microscopic worm that was survived in the Siberian permafrost for a record-breaking 46,000 years.
That’s tens of thousands of years older than any previously resurrected worms.
The ancient roundworm, or nematode, is a new species called Panagrolaimus kolymaensis.
It was discovered in 2002 inside a fossilized squirrel burrow in the Siberian permafrost. While the nematode was frozen for thousands of years, scientists were able to revive it in 2018.
This week, a new study published in PLOS Genetics explains that the nematode could survive in the permafrost for so long by entering a state of suspended animation called cryptobiosis.
‘Survival in extreme environments for prolonged periods is a challenge that only a few organisms are capable of,’ researchers wrote in the study.
In cryptobiosis, the nematode’s metabolism slows down and its cells dehydrate. This allows the nematode to survive for long periods of time in harsh conditions.
This particular worm entered cryptobiosis in the late Pleistocene that spanned 2.6 million to 11,700 years ago, an epoch that included that last ice age.
Since then, the permafrost has never thawed making this the longest recorded cryptobiosis in nematodes according to the study.
Until now, the Antarctic nematode species Plectus murrayi and a Tylenchus polyhypnus specimen held this record. The former was frozen in moss for 25.5 years and the latter was in a herbarium for 39 years.
The discovery shows that some organisms can survive for extremely long periods in frozen environments. Other ancient organisms could still be frozen in the permafrost, waiting to be discovered.
Researchers noted that extinct nematode species could be revived if they escape from the permafrost, with th potential to cause ‘drastic changes’ to the environment.
Fluctuations in temperature and natural radioactivity, can wake ancient nematodes from their deep slumber, said researchers.
The discovery of the nematode has also raised questions about the future of the melting permafrost as the Earth’s climate warms.
This could release ancient organisms into the environment, causing a significant impact on the Earth’s ecosystems.
Scientists have warned that climate change could hasten the release of ‘time-travelling’ pathogens from melting permafrost, increasing threats to the global environment and humanity.
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