The S-Allele for self-incompatability in plants has long been a subject  for theoretical analysis, since, through frequency dependence, it  maintains dozens of alleles in even small populations.  Previous work has  been based on single patch models or on stepping-stone configurations  with constant population sizes.  In collaboration with Josh Kohn (UCSD)  and Adam Richman (Montana State University), I'm developing java-based  model that incorporates local extinction of a patch followed by a  colonization and founder event.  The model tracks alleles and genetic distance data, such as F_ST.  Metapopulation dynamics increase isolation with distance and reduce the regional number of alleles.