  The fact that certain "extraordinary" probabilistic phenomena--in particular,
macroscopic violations of the second law of thermodynamics--have never been
observed to occur can be accounted for by taking hard preclusion as a basic
physical law; i.e. precluding from existence events corresponding to very small
but nonzero values of quantum-mechanical weight. This approach is not
consistent with the usual ontology of the Everett interpretation, in which
outcomes correspond to branches of the state vector, but can be successfully
implemented using a Heisenberg-picture-based ontology in which outcomes are
encoded in transformations of operators. Hard preclusion can provide an
explanation for biological evolution, which can in turn explain our subjective
experiences of, and reactions to, "ordinary" probabilistic phenomena, and the
compatibility of those experiences and reactions with what we conventionally
take to be objective probabilities arising from physical laws.
