“If dust in sand from the Sahara Desert can be blown to the Amazon, then tardigrades almost assuredly could undergo the same sort of circulation within the atmosphere,” says Boothby.
“They might get deposited in a place that’s quite austere. Maybe it’s cold, maybe it’s hot, maybe it doesn’t rain, or maybe it rains all the time. Maybe they’re on the top of a mountain where they’re exposed to more UV radiation. So perhaps tardigrades have evolved to survive all these stresses because they’ve been exposed to them.”
However, while water bears often have to cope with drying out, it’s less clear why they would need to survive baking hot temperatures, being cooled to just above absolute zero, or radiation only found in outer space.
Whatever the case, decoding the mystery behind these creatures’ amazing abilities may not just help humans – be it through improving storage of vaccines, reducing the harmful effects of radiotherapy, or preserving food for long distance spaceflight. It could also help to protect tardigrades themselves from the harmful effects of climate change.
Correction: A previous version of this article misstated Thomas Boothby’s university affiliation. He is an associate professor at the University of Wyoming. The article was originally published on 18 September 2025 and updated 19 September 2025.
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