Tardigrades: Toughest Animal Ever

Space.com reported today fascinating new work on tardigrades in space. Tardigrades, aka water bears, are microscopic invertebrates that can survive almost anything, desiccation, heat, cold, you name it. Now they have reached new heights, literally. The European Space Agency shot them into space last year and recently retrieved them. They not only survived vacuum, extreme cold, cosmic radiation and UV radiation from the sun 1000 times what reaches the surface, but were able to reproduce just fine afterwards. They are the gold medalists of eukaryote (multicellular) survivalists. They rank right up there with my favorite unicellular organism, Deinococcus radiodurans (although I think they are now called Micrococcus), which can withstand enough radiation to melt Pyrex glass. Their DNA can be shredded and they just put it back together and keep on ticking. Timex must be supremely jealous. What keeps these bacteria in check, you may ask? Because they grow incredibly slowly and are thus outcompeted for resources by pretty much everything else, so they only live in the fringes where nothing else can. Still, they are awesomely cool.