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I am looking for examples of physical indeterminacy impacting the macroscopic world. By physical indeterminacy, I mean physical sources of randomness such as quantum indeterminacy or brownian motion.
One example is of particular interest here: whether such randomness influences which sperm cell fertilizes a particular ovum, or whether such biological systems are too large to be affected by random perturbations, either at the atomic level (quantum) or molecular level (brownian motion).
Some kinds of mutation provide an example of this kind of indeterminacy. UV light can be bad for our health. One of the reasons is that, when we are exposed to sunlight, UVB photons are absorbed by double bonds in pyrimidines, which break open, become reactive, and dimerize (photo-dimerization). This damages the DNA in the same way that it would damage a zipper if 2 adjacent teeth were fused together. The cell responds to this kind of damage with a repair process that may lead to mutation. Eventually the effect of the mutation will be manifested macroscopically. The causal sequence is complex, but it starts with a photon, which has an indeterminate path due to quantum indeterminacy. It is indeterminate whether a photon will hit a particular site in the genome.
