Several years ago a friend suggested I read Rare Earth: Why Complex Life is Uncommon in the Universe. I read the book but was pretty annoyed at it. Among other things that I thought were faulty one of the claims was that a low radiation environment was required for life. I was skeptical. Sure, all life as we know it is damaged by radiation but that doesn’t mean that some life form couldn’t evolve that actually required radiation, right? Wouldn’t intelligent life from that evolutionary chain conclude the earth would be lifeless because the lack of radiation required for certain of their life processes didn’t exist?
It turns out we now have life on earth that flourish in a high radiation environment. You can thank the Chernobyl disaster for that.