Mike Shaw is a quiet, unassuming man in love with the wilderness. He also knows far more about tardigrades then almost anyone. These microscopic creatures, whose name comes from the German for “slow walker,” and who are sometimes called “water bears,” after their bear-like gait, are biological oddities. While their nervous system looks and acts like us, they are wholly different and can survive in extreme situations that almost no other living organism can – including space.
Beginning in 2007, biologists sent these little suckers up to the space station (along with other so-called extremophiles) and found that tardigrades can survive the vacuum of space and the life-zapping radiation of the sun. Other experiments have shown that adult tardigrades can survive both extreme pressures and temperatures, ranging from -459 degrees Fahrenheit up to 300 degrees Fahrenheit. Even if recent DNA and RNA sequencing show that tardigrades are the sister group to arthropods and Onychophora, their evolutionary lineage is unclear. Some have even theorized – cue the X Files music – that tardigrades came from another planet, and rode to Earth on space debris.
Their secret? The little water bear is one of few groups of species that are capable of reversibly suspending their metabolism and going into a dehydrated state called cryptobiosis. In this kind of suspended animation, a tardigrade’s metabolism lowers to less than 0.01% of normal, with water content dropping to 1% of normal. No wonder they’ve got staying power: some 1,150 species of tardigrades have been described throughout the world, and they’ve been found to live virtually everywhere, from the Himalayas (above 20,000 feet), to the deep sea (below 13,000 feet) and from the polar regions to the equator. motherboard.vice.com