The popularity of the Darwin awards notwithstanding, mortality is not the only mechanism by which evolutionary pressure is applied - simply influencing the likelihood of having children (and recursively onward through descendants) is sufficient.
That gives wide latitude for more subtle influences (e.g. attractiveness, desire to have children) to have a large impact.
Not the main point, but it should be noted that the Darwin Awards are wide open to candidates with outstanding self-sterilizations, not just people that remove themselves from the gene pool by dying (hilariously).
That's a good point. I just wanted to emphasize that an epigenetic error being passed on is not a measure of its utility to an organism, rather, it is a necessary precondition for the resulting trait to be tested against the environment. Being a necessary element of "natural selection", the meta statement of calling this propagation a positive utility seems a bit incorrect, if only in verbiage.
That gives wide latitude for more subtle influences (e.g. attractiveness, desire to have children) to have a large impact.