>>28513433The smaller a creature becomes, the less complex they become and the easier it is to survive harsh conditions, especially if they are built specifically to survive those conditions. The water bear just happens to have evolved the means to deal with the harshest shit life can throw at it, but only because it's at a microscopic level.
On another level of biology, theres the Immortal Jellyfish, a jellyfish that is capable of regressing to it' polyp stage at the end of it's life and re-living it's life from the start. It's unlikely any other creature of more complex biology could do such a thing naturally, and the jellyifsh can get away with it because it's barely a sentient creature to begin with, thus it's simplicity gives it a lot of leeway in what shit it gets away with.
