This is a question which bridges the gap between biology and physics... but I thought this was the best place to ask it.
I remember reading a while ago that it is thought that neutrinos may play a role in evolution. There are billions passing through our body every second, and a small proportion will interact with atoms in our body through colliding masses and/or the weak interaction. This encourages random mutations within DNA (I guess specifically reproductive DNA) that leads to random differences between generations - survival of the fittest then takes care of the rest.
Although this seems plausible, I can't seem to find any information to back it up. Has anyone heard of this effect? Would standard radioactive decay be enough to explain random mutations?