Spatial Mendelian games

This paper considers complex models arising in sociobiology. These combine genetic and strategic aspects to model the effect of gene-linked strategies on the ability of individuals to survive to maturity, mate and produce offspring. Several important models considered in the literature are generalised and extended to incorporate a spatial aspect. Individuals are allowed to migrate. Contests, e.g. for food or amongst males for females, take place locally. The choice of the point at which the population structure is measured affects the complexity of the equations describing the system, although it is possible to utilise any point in the life cycle. For our spatial models the simplest approach is to measure the population structure immediately after migration. A saddle point method, developed by the authors, has previously been used to obtain results for simple discrete time spatial models. It is utilised here to obtain the speed of first spread of a new gene-linked strategy for the much more complex sociobiological models included in this paper. This demonstrates the wide-ranging applicability and power of the method.