Scientists have successfully revived roundworms that were in the dormant stage for 46,000 years in the Siberian permafrost. They were discovered in 2018 and have now not only been revived but reproduced.
These roundworms (nematodes), known as Panagrolaimus, have since become the subject of further research, leading to the proposal that one of the nematode varieties represents a new species called Panagrolaimus kolymaensis.
The new research, published in the journal PLOS Genetics on July 27, 2023 by Shatilovich and coworkers, provides more insights into the survival mechanisms of these ancient worms.
The researchers conducting radiocarbon dating using plant material found along with the samples, concluded that Panagrolaimus kolymaensis worms are actually 46,000 years old.
This age places them in the late Pleistocene when woolly mammoth and sabre tooth tigers roamed the world.
The worms were found in a fossilised squirrel burrow more than 120 feet below ice by Russian scientists near the Kolyma river in northeastern Siberia.
They were in a state of suspended metabolism called cryptobiosis.
With cryptobiosis, the organism can live without any metabolism for a period until the conditions are favourable again. All functions including reproduction, development and repair, stop due to the inactivation of the metabolic activities.
Some organisms survive without water for a long period of time m in places where there is nonavailability of water like yeast, mosses, and algae. Similarly, there are others that temporarily suspend metabolic functions when there is a lack of oxygen or a high level of toxins, freezing or boiling temperature in the external environment.
These worms were revived at the Institute of Physicochemical and Biological Problems in Soil Science RAS in Russia.
Scientists feel that it would be very helpful to know how the worms adapted and survived for such a long period and in such an extreme environment. It would help us gain knowledge about how life survives such harsh environmental conditions.
By slowly and gently thawing the roundworms, researchers were able to bring these worms back to life, and the worms could wriggle, eat, and reproduce.
One of the worms was bred in a laboratory for 100 generations, as they were found to reproduce parthenogenetically without a male partner. The genetic analysis revealed that the Panagrolaimus worms belong to a new species, named Panagrolaimus kolymaensis, named after the Kolyma River near where they were found.
These nematodes expressed their remarkable ability to suspend life over geological time scales.
Comparative genome analysis between P. kolymaensis and another nematode species, Caenorhabditis elegans, reveals similarities in the molecular toolkit for surviving desiccation and freezing.
The researchers successfully induced the nematodes to enter and exit the dormant state of cryptobiosis using special preparatory cues.
While the findings are intriguing, skepticism about the study’s results are seen regarding the possibility of modern contamination and whether the analysis proves the worms’ age definitively.
Obviously these biological mechanisms are of great interest to human kind because with that knowledge, “suspended animation” of humans till now science fiction, could become a reality. We have always toyed with the idea of creating in the laboratory a live Dianosaur out of dianosaur eggs which are discovered from time to time. But this is human fantasy and nothing close to a real possibility even now because there is a huge difference between reviving single cell organisms and a dianosaur.
Nonetheless, the research sheds light on the remarkable ability of these nematodes to survive extreme conditions over geological time scales, providing insights into their evolutionary processes and survival strategies.
The research holds significance for understanding evolutionary processes and could aid conservation efforts for endangered species, especially in the face of climate change and extreme heat.
Studying how these creatures survive extreme environments in cryptobiosis may provide insights into how animals can adapt, as habitats shift due to changing climates.
To study such ancient organisms and their ability to revive offers valuable knowledge about survival mechanisms and may challenge the notion of extinction if animals can endure for millennia in a dormant state.
They survive because they have developed certain genetic makeup and biochemical mechanisms to do so.
A Delhi University Professor of Zoology, Dr Rita Rath, says, “The revival of the 46,000 years old round worms from Siberian permafrost is incredible. This discovery not only sheds light on their remarkable ability to survive in cryptobiosis but also offers valuable insights into how organisms can adapt to extreme climate conditions over geological timescales.”
She said, “Studying these creatures may hold the key to understanding evolutionary processes and conservation efforts in the face of climate change.”
| Posted by Sameer Khan | 
