Gotta disagree; actually a lot stops those effects. There are multiple mechanisms for DNA repair besides good old natural selection. Life developed in a mutage

Gotta disagree; actually a lot stops those effects. There are multiple mechanisms for DNA repair besides good old natural selection. Life developed in a mutagenic environment and there are natural sources of radiation all around us. Granite is measurably radioactive, for instance. Artificial radiation at much lower doses are not going to make a significant difference; they’re just very easy to detect because of the very precise energy signature they show on things like gamma ray spectrometers.