Consider a sample of three chromosomes from a population of size N diploid individuals. Assume that both mutation and coalescent events can occur, but that, at most, only one event can occur in a given generation. Moving backwards in time, what is the probability that:
a) A coalescent event happens one generation ago
b) A mutation event happens one generation ago
c) A mutation or a coalescent event happens one generation ago
d) Going back in time, the first event to happen is a coalescent event
e) There is at least one genetic variant in the sample