This week is the Tardigrades, a micro-animal with abnormal qualities. Holly Carter reports
Tardigrades, also adorably known as water bears or moss piglets, are a tiny eight-legged micro animal. They also happen to be the toughest creature on earth. At only 0.5mm long when fully grown, they can live anywhere on the planet, and have been found pretty much everywhere from tropical rainforests to the Antarctic. They spend most of their lives living on and eating moss, as well as sucking up water from their surroundings. They are also found on dunes, beaches, soil, water sediments and even under ice. They can potentially survive for 30 years without any sustenance if conditions get too hard.
For no apparent reason, tardigrades can withstand 6 times the pressure of the deepest ocean on earth, survive 100 times the radiation that would kill a human, and endure temperatures down to absolute zero (-273oC) and up to 150oC. To survive these temperatures, they have to temporarily suspend their metabolism, only to revive and thrive when conditions improve. It’s a mystery why tardigrades evolved to be this tough when no conditions on planet earth would ever have been extreme enough to necessitate it.
Because of their resilience, these tiny, plump creatures have been sent to space, and were the first species from earth to survive exposure to space in 2007. If a human were to go to space unprotected, their blood would boil and radiation would rip apart the DNA in your cells, to name but a few of the horrific effects of being exposed to no atmosphere and huge amounts of radiation. The tardigrades, however, did not only survive, but survived for their whole 10 day exposure to incredible levels of UV radiation, and were completely healthy when they got back to earth. Some of them had even reproduced! The European Space Agency have a dedicated tardigrade mission called ‘Tardigrades in Space’, which is pleasingly shortened to TARDIS, and it aims to investigate further the conditions that tardigrades can survive. They may be tiny, but these little creatures are tough. They’ve been on earth since long before humans evolved, and will probably outlive us all.