A resilient micro animal, known as the water bear, will be the last living thing on Earth.
That’s according to a new study published this month, which claims the tiny tardigrade, or water bear, is uniquely equipped to survive the apocalypse.
The water bear, so named in 1773 for its distinctive, slow-moving gait (apparently similar, in the eyes of German zoologist Johann Goeze, to a perambulating grizzly) is a microscopic invertebrate, about as big as a grain of salt.
Small, maybe, but these critters are fiercely robust – the extremist of extremophiles – able to survive the crushing pressures of the deepest ocean or the frigid vacuum of space.
Don’t they know it’s the end of the world?
It should come as no surprise then, that any number of doomsday scenarios, from nuclear war to global warming, while undoubtedly spelling the end for you or I, would hardly cause this miniature survivalist to bat an eye.
This latest study, published in Scientific Reports, concluded it would take something so cataclysmic as to burn away the Earth’s oceans before the water bear would succumb, and that can’t happen for billions of years, not before the sun swells to a red giant and consumes the Earth.
So what’s their secret?
It’ all down to their unique biology, and an otherworldly process straight off the pages of a bad sci-fi novel, known as cryptobiosis.
In simple terms, cryptobiosis enables the tardigrade to slow its metabolism to a crawl, and enter a state of suspended animation. A neat trick, if you’re eager to avoid a nuclear winter or the after-effects of an asteroid strike.
Add to this an immunity to radiation and a Dr Who-like ability to regenerate, and we’re looking at the world’s smallest superhero.
Grizzly or Gummy?
It’s easy to get carried away with this amazing creature…and scientists often do, imbuing the humble water bear with near mythic qualities – the power to cheat death, to live forever, to exist in the harshest, most inhospitable places, on Earth and beyond…
But here’s the caveat.
For one, cryptobiosis, the water bear’s go-to power-move, takes time; it’s a complicated, drawn-out process in which the creature retracts its head and legs and leeches all the moisture from its system. The whole thing can take several hours, so any critters caught in the path of the meteorite or the blast zone of the nuke would be vaporised right along with us.
And they can’t maintain their bio-stasis indefinitely; in fact, the only real experiment ever conducted in this area revived its desiccated subjects after just eight years (although one experiment did claim ‘leg movement’ after more than a hundred).
And as for surviving in outer space, this oft quoted factoid is more than a little misleading. It stems from an experiment in 2007, and if you check the data, it’s ambiguous at best.
Of the water bears blasted into orbit, only a handful managed to reanimate back on Earth…and few of those survived for very long.
Smarter than the average bear
But this micro monster is tougher than most, surviving five mass extinctions, outliving the trilobites, the dinosaurs, and ultimately, us.
And while we may be little more than an evolutionary eye-blink, water bears, in their microscopic kingdoms, will probably be here to the bitter end, until the sun finally burns out and swallows the Earth.