the planet's toughest creatures
The humble tardigrade seems to survive anything we throw at it. But how?
In early September, a small batch of tiny invertebrates called tardigrades (or water bears) was launched into space without any protection. The tiny creatures survived, came back safely and continued to breed normally, with no notable radiation damage. So what's their secret? Theyre anhydrobiotic organisms, living things that evolved to survive extreme droughts by entering a state of suspended animation and repairing their DNA when its damaged by a lack of water.
Deep inside their cells are pristine DNA fragments that can be used to replace or fix a damaged section of its genome through a process known as annealing. (read a very detailed explanation of how it works) This ability is so unique, its been proposed that anhydrobiotic creatures came from outer space and are proof of panspermia.
Its an even more tempting proposition when we consider the fact that we are too complex and too big to have such an ability. The extreme conditions that require extreme adaptations aren't conductive to complex, macro-organisms. Theyd die before they would be able to develop enough structure and complexity.
So could a colony of alien creatures related to water bears and super-tough bacteria evolve on another world, get blasted into space by an explosion, survive the millions of years it takes to travel to another planet and help spark life on this one? How about putting this idea to the test by blasting water bears to Mars and checking up on them with one of the rover missions there? How expensive could it be to blast a piece of rock to Mars and how much could we learn?
