Title: A stage-structured model of a single species:
       linear stability and travelling wave-fronts
 
Abstract: In this talk I will derive a reaction-diffusion model
      of two equations, one for the immature and one for the
      mature members of a single species. The system is partially
      coupled, in that the second equation involves only the
      mature species (though the diffusivity of the immatures
      appears as a parameter). I will
      discuss the existence of travelling
      wave-front solutions of the `mature' equation and how these
      compare with the well-known travelling front solutions
      of Fisher's equation. Existence of such solutions can be
      proved rigorously for the case when the immatures are
      immobile or move very slowly. In contrast to the delayed
      Fisher equation, travelling fronts of this model appear
      to be monotone for all values of the delay.