It sounds like a scene from a movie, but it’s all true: a tiny worm, frozen for more than 46,000 years in the Siberian permafrost, has been “reactivated” by a group of scientists. It didn’t take much: a little heat in the laboratory, and he started moving again.
That little worm, now renamed Panagrolaimus kolymaensis, not only woke up, but started living and feeding again as if nothing had happened. And no, it’s not just a laboratory curiosity: this discovery also has a lot to say about our present, from medicine to the conservation of biodiversity.
A living being literally out of the ice age
The worm was found in a fossil burrow, sealed in ice near the Kolyma River in northeastern Siberia. Scientists have dated the plant fragments found with him: they date back to around 46,000 years ago, i.e. to the late Pleistocene.
At that point, researchers analyzed his DNA. Result? It was not an already known species. After months of genetic comparisons and morphological studies, it was officially classified as a new species, named indeed Panagrolaimus kolymaensis.
The most surprising detail? This nematode reproduces without the need for males, thanks to a mechanism called parthenogenesis. It even has three copies of each chromosome (it is triploid), a genetic strategy that probably contributed to its incredible resistance.
How did he survive? The secret is in the “biological pause”
The real question, the one that has kept researchers awake for months, is: how did it survive for 46,000 years without actually dying? The answer lies in a process called cryptobiosis. In practice, the worm managed to suspend every vital function: no heartbeat, no metabolism, no cellular activity. As if he had pressed the “pause” button on his existence, waiting for better times.
Conditions such as extreme cold, the absence of oxygen and the dry environment of the permafrost did the rest, creating a sort of “natural freezer”.
Scientists compared the genome of Panagrolaimus kolymaensis with that of another worm, the famous Caenorhabditis eleganswhich is often used as a model organism in laboratories around the world. And they found something incredible: they share the same genes linked to cryptobiosis, activated at key moments to survive frost or drought.
What can we learn from him
What seems like an isolated fact actually concerns very concrete issues. If we understood well how Panagrolaimus kolymaensis protects its cells, we could improve techniques for preserving organs, tissues or embryos in the medical field, reducing the use of toxic substances or temperatures that are impossible to manage.
The researchers also tried to replicate the method on C. elegans: by drying it before freezing, they managed to keep it viable for over 480 days at -80 °C, something unthinkable until a few years ago.
The heart of the discovery is precisely this: before freezing, the worm “prepares” itself, accumulating sugars such as trehalose, which protect the cells, making them stable even for millennia.
Because it’s not just a scientific discovery (but also a warning)
As the permafrost gradually melts, other living beings such as Panagrolaimus kolymaensis could return to light. Some may be harmless, others who knows. But one thing is certain: these organisms carry with them ancient genetic memory, evolutionary strategies that could change the way we think about life.
This little worm shows us that life can slow down, adapt, resist, and then start again, even after tens of millennia. A powerful reminder, today more than ever.
You might also be interested in:
