It seems like constant population size is one of the most important assumptions here, but it's not really discussed. It's obvious from the code given that the author is fully aware of the importance of this assumption, but it is such a blatant separation from the real world that I would think it deserves some discussion - e.g. although we know human population has grown exponentially, how do we approximate the error between what the function gives us and what actually happened genetically?
