Will mutations become less freqent?

The implication of the study would seem to suggest that DNA polymerases must have a simple way with dealing double strand breaks during synthesis more than just occasionally, to me anyway. From the amount of double strand break suggested the non-template nucleotides (which are stated to occur very often) would be intergrated at an amazing rate, more than is tenable except maybe in the case of a cancer. What am I missing?More to the point of the OP, and since it has already been stated more thoroughly I'll express it more succinctly in my layman's terms: lower mutation rate = less basis for selection = extinction due to the slightest variance in environmental pressure. Which really isn't a very viable model.