  Cell polarity refers to the spatial asymmetry of molecules on the cell
membrane. Altschuler, Angenent, Wang and Wu have proposed a stochastic model
for studying the emergence of polarity in the presence of feedback between
molecules. We analyze their model further by representing it as a model of an
evolving population with interacting individuals. Under a suitable scaling of
parameters, we show that in the infinite population limit we get a
Fleming--Viot process. Using well-known results for such processes, we
establish that cell polarity is exhibited by the model and also study its
dependence on the biological parameters of the model.
