It is a common science fiction trope to put someone into ice for thousands, or even millions, of years before thawing them out and bringing them back to life. It makes for some great stories, but the science behind it is far more complex than the TV shows would have you believe.

Just because it isn’t easy, however, doesn’t mean it isn’t possible, and proof of that, on a much smaller level, comes from a rotifer.

Rotifers are microscopic aquatic animals that live in fresh water or within layers of liquid surrounded by soil. They are known to be very tough, surviving in very low oxygen environments, going long periods of time without food, and yes, even being frozen for extended periods of time.

Up until recently, the longest that a rotifer was frozen and then reanimated was about ten years, which is quite impressive. In 2021, however, scientists working at the Soil Cryology Laboratory at the Institute of Physiocochemical and Biological Problems in Soil Science in Pushchino, Russia, extended that limit quite significantly.

The team took a sample from deep within the Siberian permafrost and began testing it to see what was there. What the team found was pretty normal, including rotifers and other microorganisms. What happened next, however, was shocking. One of the rotifers began moving and quickly went back to living a normal life.

In a study published in Current Biology, the researchers explained:

“The core contained ice-rich loam from the Late Pleistocene Yedoma formation (also called the Ice Complex). The shape, good development and wide distribution of ice wedges, and occasional finding of well-preserved mammal mummies support syncryogenetic formation of the Ice Complex, i.e. that layers of sediments were frozen relatively quickly after their formation and have never melted.”

That ice froze between 24,960 and 24,485 years ago, which means the tough little rotifers have survived this entire time and emerged in a seemingly healthy way. They even went through the process of parthenogenesis, which is their method of reproducing. In a statement on this, study author Stas Malavin of the Soil Cryology Laboratory said:

“Our report is the hardest proof as of today that multicellular animals could withstand tens of thousands of years in cryptobiosis, the state of almost completely arrested metabolism.”

While this is not the oldest organism to emerge from cryptobiosis, it is the first time this species has been seen doing it. Since this species has a basic brain and gut, it is quite surprising. Malavin explained:

“The takeaway is that a multicellular organism can be frozen and stored as such for thousands of years and then return back to life – a dream of many fiction writers. Of course, the more complex the organism, the trickier it is to preserve it alive frozen and, for mammals, it’s not currently possible. Yet, moving from a single-celled organism to an organism with a gut and brain, though microscopic, is a big step forward.”

There are already some humans who have been put into a deep freeze with the hope of being able to be thawed out and reanimated someday. While it is still unlucky for those people, this new study does give some hope that this type of thing may be done successfully in the future.

If you enjoyed this post, you might love this video of an octopus showing off.