Thanks for your contribution, Peter. One thing I know (and you all may tell me if I'm wrong) is that life originated on Earth, or at least it was imported by comet impacts and later developed on Earth, IN AN OZONE-PROTECTED environment. This does not mean that life could have never evolve otherwise, but I'm pretty sure it should have been DIFFERENT under the crude impact of UV radiation.

How will embryonal cells develop under UV bombardment ? Probably life will suffer a process of adaptation, where the strongest will survive. Then, who are the strongest ?

Un abrazo - Andrés