This means there must be errors in the genetic code that are not so severe as to kill the individual organism before it reproduces, but rather survive to aide in the exploration of new or changing ecological niches. A supernova of the type used to measure cosmic distances, photographed in 1994. When the total mass of the white dwarf hits a certain limit, it blows to pieces. It turns out that most mutation is driven by chemical processes and is kept in check by genetic repair mechanisms. It also turns out that most living things survive in a natural radiation environment that is near to, but comfortably below the lethal level.
Some bacteria are remarkably resistant to radiation .
There are even strong similarities between these processes of genetic transplantation and the combining of zygotes in sexual reproduction. There are suggestions that the development of sexual reproduction, so much more efficient in creating genetic diversity than simple cell mitosis, was a variation on the theme of radiation repair. All these issues involve radiation in some intimate way. I suspect not. Just as we have found that our planet represents a tightly intertwined ecology involving all living things, I believe that the future of astrobiology will reveal that Earth is part of a galactic ecology and that life here, and elsewhere, is intermeshed with and dependent upon astronomical events throughout the galaxy.